MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00001 

              00001 ;SYSRES/ASM - LS-DOS 6.2
000A          00003 LF      EQU     10
000D          00004 CR      EQU     13
              00005 ;
              00006 ;*LIST  OFF                     ;Xref of Lowcore
0000          00007 *GET    LDOS60/EQU:2
08F0          00008 @$SYS   EQU     08F0H
0000          00009 @@1     DEFL    0000H
0000          00010 @@2     DEFL    0000H
0000          00011 @@3     DEFL    0000H
0000          00012 @@4     DEFL    0000H
0877          00013 @BANK   EQU     0877H
FFFF          00014 @BLD631 EQU     0FFFFH
FFFF          00015 @BLD631C        EQU     0FFFFH
FFFF          00016 @BLD631D        EQU     0FFFFH
FFFF          00017 @BLD631E        EQU     0FFFFH
FFFF          00018 @BLD631F        EQU     0FFFFH
FFFF          00019 @BLD631G        EQU     0FFFFH
FFFF          00020 @BLD631H        EQU     0FFFFH
1300          00021 @BYTEIO EQU     1300H
0689          00022 @CHNIO  EQU     0689H
0553          00023 @CKBRKC EQU     0553H
0545          00024 @CLS    EQU     0545H
0623          00025 @CTL    EQU     0623H
06E3          00026 @DIV16  EQU     06E3H
0642          00027 @DSP    EQU     0642H
052D          00028 @DSPLY  EQU     052DH
0000          00029 @FRENCH EQU     0000H
0000          00030 @GERMAN EQU     0000H
0638          00031 @GET    EQU     0638H
07BD          00032 @HEX16  EQU     07BDH
07C2          00033 @HEX8   EQU     07C2H
06F8          00034 @HEXD   EQU     06F8H
06F6          00035 @HEXDEC EQU     06F6H
0000          00036 @HZ50   EQU     0000H
0000          00037 @INTL   EQU     0000H
0630          00038 @JCL    EQU     0630H
0635          00039 @KBD    EQU     0635H
0628          00040 @KEY    EQU     0628H
0585          00041 @KEYIN  EQU     0585H
0089          00042 @KITSK  EQU     0089H
0503          00043 @LOGER  EQU     0503H
0500          00044 @LOGOT  EQU     0500H
0000          00045 @MOD2   EQU     0000H
FFFF          00046 @MOD4   EQU     0FFFFH
0530          00047 @MSG    EQU     0530H
06C9          00048 @MUL16  EQU     06C9H
0084          00049 @OPREG  EQU     0084H
0528          00050 @PRINT  EQU     0528H
063D          00051 @PRT    EQU     063DH
0E29          00052 @PRTIMO EQU     0E29H
0645          00053 @PUT    EQU     0645H
0FE9          00054 @RSTNMI EQU     0FE9H
0680          00055 @RSTREG EQU     0680H
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00002 

078D          00056 @TIME   EQU     078DH
FFFF          00057 @USA    EQU     0FFFFH
0B99          00058 @VDCTL  EQU     0B99H
0D38          00059 @VDCTL3 EQU     0D38H
0935          00060 @VDPRT  EQU     0935H
0D42          00061 @_VDCTL EQU     0D42H
0DF1          00062 ADDR_2_ROWCOL   EQU     0DF1H
0201          00063 BAR$    EQU     0201H
439D          00064 BOOTST$ EQU     439DH
0200          00065 BUR$    EQU     0200H
0A7B          00066 CASHK$  EQU     0A7BH
006C          00067 CFLAG$  EQU     006CH
0300          00068 CORE$   DEFL    0300H
F800          00069 CRTBGN$ EQU     0F800H
0033          00070 DATE$   EQU     0033H
07A8          00071 DATELO$ EQU     07A8H
04C7          00072 DAYTBL$ EQU     04C7H
0031          00073 DCBKL$  EQU     0031H
0470          00074 DCT$    EQU     0470H
006D          00075 DFLAG$  EQU     006DH
0846          00076 DIS_DO_RAM      EQU     0846H
0B94          00077 DODATA$ EQU     0B94H
0210          00078 DODCB$  EQU     0210H
0C44          00079 DO_CONTROL      EQU     0C44H
0CB8          00080 DO_DSPCHAR      EQU     0CB8H
0C8C          00081 DO_INVERT_DIS   EQU     0C8CH
0C89          00082 DO_INVERT_ENA   EQU     0C89H
0C9B          00083 DO_INVERT_OFF   EQU     0C9BH
0000          00084 DO_MASK EQU     0000H
0BCB          00085 DO_RET  EQU     0BCBH
0BCC          00086 DO_RET1 EQU     0BCCH
0CCE          00087 DO_SCROLL       EQU     0CCEH
0BEA          00088 DO_TABS EQU     0BEAH
04C0          00089 DSKTYP$ EQU     04C0H
04C2          00090 DTPMT$  EQU     04C2H
0FF4          00091 DVREND$ EQU     0FF4H
0206          00092 DVRHI$  EQU     0206H
0817          00093 ENADIS_DO_RAM   EQU     0817H
000E          00094 FDDINT$ EQU     000EH
006A          00095 FLGTAB$ EQU     006AH
0DAE          00096 GET_@_ROWCOL    EQU     0DAEH
0750          00097 HERTZ$  EQU     0750H
040E          00098 HIGH$   EQU     040EH
0072          00099 IFLAG$  EQU     0072H
0420          00100 INBUF$  EQU     0420H
003E          00101 INTVC$  EQU     003EH
0203          00102 JCLCB$  EQU     0203H
0230          00103 JLDCB$  EQU     0230H
07D6          00104 KCK@    EQU     07D6H
0074          00105 KFLAG$  EQU     0074H
08FC          00106 KIDATA$ EQU     08FCH
0208          00107 KIDCB$  EQU     0208H
0202          00108 LBANK$  EQU     0202H
0401          00109 MAXDAY$ EQU     0401H
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00003 

0076          00110 MODOUT$ EQU     0076H
04DC          00111 MONTBL$ EQU     04DCH
0077          00112 NFLAG$  EQU     0077H
0078          00113 OPREG$  EQU     0078H
086E          00114 OPREG_SV_AREA   EQU     086EH
0835          00115 OPREG_SV_PTR    EQU     0835H
0410          00116 PAKNAM$ EQU     0410H
0382          00117 PAUSE@  EQU     0382H
07AF          00118 PCSAVE$ EQU     07AFH
001B          00119 PDRV$   EQU     001BH
0218          00120 PRDCB$  EQU     0218H
0DCD          00121 PUTA@DE EQU     0DCDH
0DCA          00122 PUT_@   EQU     0DCAH
0DC6          00123 PUT_@_ROWCOL    EQU     0DC6H
007B          00124 RFLAG$  EQU     007BH
0DD0          00125 ROWCOL_2_ADDR   EQU     0DD0H
04C4          00126 RSTOR$  EQU     04C4H
0238          00127 S1DCB$  EQU     0238H
0CF3          00128 SET_SCROLL      EQU     0CF3H
007C          00129 SFLAG$  EQU     007CH
0220          00130 SIDCB$  EQU     0220H
0228          00131 SODCB$  EQU     0228H
0380          00132 STACK$  EQU     0380H
0000          00133 START$  EQU     0000H
002D          00134 TIME$   EQU     002DH
002C          00135 TIMER$  EQU     002CH
002B          00136 TIMSL$  EQU     002BH
0713          00137 TIMTSK$ EQU     0713H
04C3          00138 TMPMT$  EQU     04C3H
07B1          00139 TRACE_INT       EQU     07B1H
0A8F          00140 TYPHK$  EQU     0A8FH
0B26          00141 TYPTSK$ EQU     0B26H
007F          00142 VFLAG$  EQU     007FH
0401          00143 ZERO$   EQU     0401H
              00144 ;*LIST  ON
0000          00145 *GET    COPYCOM:3               ;Embed copyright notice
              00146 ; COPYCOM - File for Copyright COMment block
              00147 ;
0000          00148 *GET BUILDVER/ASM:3
              00149 ;
              00150 ;       Buildver/asm is a bit of a kludge since not all utilities can load
              00151 ;       equates from LDOS60 and still compile.  LOWCORE and everybody else
              00152 ;       relies on this setting, and it eventually ends up in LDOS60/EQU
              00153 ;       for programs that can use that.
              00154 ;
FFFF          00155 @BLD631         EQU     -1      ;<631>Build 631 distribution (LEVEL 1B)
              00156 ;       These switches activate patches made since the 1B release.
              00157 ;       It is important that all earlier patches be enabled when a higher
              00158 ;       patch is enabled.
              00159 ;       Patches C thru F were published in TMQ IV.iv, page 32 (NOTE: the
              00160 ;       patch addresses listed for SPOOL in SPOOL1/FIX are 19H high.)
FFFF          00161 @BLD631C        EQU     -1      ;<631>Apply 1C patches (SETKI)
FFFF          00162 @BLD631D        EQU     -1      ;<631>Apply 1D patches (DIR)
FFFF          00163 @BLD631E        EQU     -1      ;<631>Apply 1E patches (DIR & MEMDISK/DCT)
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00004 

FFFF          00164 @BLD631F        EQU     -1      ;<631>Apply 1F patches (SPOOL)
              00165 ;       Patches G and H were published in TMQ V.i, pages 10 and 18/19.
FFFF          00166 @BLD631G        EQU     -1      ;<631>Apply 1G patches (//KEYIN,DIR,DO *)
FFFF          00167 @BLD631H        EQU     -1      ;<631>Apply 1H patches (MEMORY)
              00168 ;
              00169 ;End of BUILDVER/ASM
              00170         IF      @BLD631
              00172         ELSE
              00173         COM     '<*(C) 1982,3,4,6 by LSI*>'
              00174         ENDIF
              00175 ;
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00005 

'System low core assignments

              00177 ;
              00178 ;       LDOS 6.2 Low Core RAM storage assignments
              00179 ;       Copyright (C) 1982 by Logical Systems, Inc.
              00180 ;
0000          00181 START$  EQU     0
0000          00182         ORG     0+START$
              00183 ;
              00184 ;       Page 0 - RST's, data, and buffers
              00185 ;
0000 F3       00186 @RST00  DI                      ;IPL Entry for R/S 4-P
0001 3E01     00187         LD      A,00000001B     ;Set image in A
0003 D39C     00188         OUT     (9CH),A         ;toggle in BOOT/ROM
0005 00       00189         DB      0,0,0           ;CP/M emulator SVC
     00 00 
0008 C9       00190 @RST08  RET
0009 0000     00191         DW      0
000B 0000     00192 SVCRET$ DW      0               ;Return address from SVC
000D 00       00193 LSVC$   DB      0               ;Last SVC executed
000E F3       00194 FDDINT$ DI                      ;NOP or DI (F3H) for
000F C9       00195         RET                     ;  System (Smooth)
0010 C9       00196 @RST10  RET
0011 0000     00197         DW      0
0013          00198 USTOR$  DS      5               ;User storage area
0018 C9       00199 @RST18  RET
0019 0000     00200         DW      0
001B 01       00201 PDRV$   DB      1               ;Current drive, physical
001C 0000     00202 PHIGH$  DW      0               ;Physical HIGH$
001E 0030     00203 LOW$    DW      3000H           ;Lowest usable memory
0020 C9       00204 @RST20  RET
0021 0000     00205         DW      0
0023 00       00206 LDRV$   DB      0               ;Current drive, logical
0024 0000     00207 JDCB$   DW      0               ;Saved FCB pointer
0026 0000     00208 JRET$   DW      0               ;Saved I/O return address
0028 C35B1A   00209 @RST28  JP      RST28           ;System SVC processor
002B 55       00210 TIMSL$  DB      55H             ;Fast=55, slow=FF
002C 00       00211 TIMER$  DB      0               ;RTC counter
002D 00       00212 TIME$   DC      3,0             ;SS:MM:HH storage area
     00 00 
0030 C3A019   00213 @RST30  JP      @DEBUG          ;DEBUG call address
0033          00214 DATE$   DS      5               ;YY/DD/MM/packed
0038 C3FF1B   00215 @RST38  JP      RST38@          ;Interrupt RST
              00216         IF      @BLD631
003B 01       00217 OSRLS$  DB      01H             ;<631>OS Release #
              00218         ELSE
              00219 OSRLS$  DB      00H             ;OS Release #
              00220         ENDIF
              00221 ;
              00222 ;       INTIM$ stores the image read from RDINTSTATUS*
              00223 ;
003C 00       00224 INTIM$  DB      0               ;Interrupt latch image
              00225 ;
              00226 ;       INTMSK$ masks the image read from RDINTSTATUS*
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00006 

'System low core assignments

              00227 ;       LDOS 6.x permits only RS-232 RCV INT, IOBUS INT,
              00228 ;       and RTC INT to be used by the TASKER off of RST38
              00229 ;
003D 2C       00230 INTMSK$ DB      2CH             ;Mask for INTIM$
              00231 ;
              00232 ;       INTVC$ stores the eight vectors associated
              00233 ;       with the INTIM$ bit assignments
              00234 ;
003E 481C     00235 INTVC$  DW      RETINST         ;Primary interrupts
0040 481C     00236         DW      RETINST,RTCPROC,RETINST
     941C 481C 
0046 481C     00237         DW      RETINST,RETINST,RETINST,RETINST
     481C 481C 481C 
              00238 ;
              00239 ;       TCB$ stores the TCB vectors for task slots 0-11
              00240 ;
004E          00241 TCB$    DS      24              ;Interrupt task vectors
              00242 ;
              00243 ;       NMI vector used in disk I/O
              00244 ;
0066          00245 @NMI    DS      3               ;Don't overlay this
              00246 ;
              00247 ;       OVRLY$ stores the system's overlay request #
              00248 ;
0069 00       00249 OVRLY$  DB      0               ;Current overlay resident
              00250 ;
              00251 ;       FLGTAB$ stores 26 flags and images. A pointer
              00252 ;       to this table is obtained from SVC-@FLAGS
              00253 ;
006A          00254 FLGTAB$ EQU     $
              00255 ;
              00256 ;
              00257 ;       AFLAG$ - Start CYL for Allocation search
              00258 ;
006A 01       00259 AFLAG$  DB      01              ;AFLAG
006B 00       00260         DB      0               ;BFLAG
              00261 ;
              00262 ;       CFLAG$ assignments:
              00263 ;        0 - Cannot change HIGH$ via SVC-100
              00264 ;        1 - @CMNDR in execution
              00265 ;        2 - @KEYIN request from SYS1
              00266 ;        3 - System request for drivers, filters, DCTs
              00267 ;        4 - @CMNDR to only execute LIB commands
              00268 ;        5 - Sysgen inhibit bit
              00269 ;        6 - @ERROR inhibit display
              00270 ;        7 - @ERROR to use user (DE) buffer
              00271 ;
006C 00       00272 CFLAG$  DB      0               ;Condition flag
              00273 ;
              00274 ;       DFLAG$ assignments:
              00275 ;        0 - SPOOL is active
              00276 ;        1 - TYPE ahead is active
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00007 

'System low core assignments

              00277 ;        2 - VERIFY is on
              00278 ;        3 - SMOOTH active
              00279 ;        4 - MemDISK active
              00280 ;        5 - FORMS active
              00281 ;        6 - KSM active
              00282 ;        7 - accept GRAPHICS in screen print
              00283 ;
006D 0A       00284 DFLAG$  DB      00001010B       ;DEV Flag (SMOOTH,TYPE)
              00285 ;
              00286 ;       EFLAG$ - Assignments: (sys13 usage)
              00287 ;       use only bits 4, 5 and 6 to indicate user
              00288 ;       entry code to be passed to SYS13. SYS13
              00289 ;       will be executed from SYS1 if this byte
              00290 ;       is NON/0, bit 4, 5 and 6 will be merged into
              00291 ;       the SYS13 (1000,1111b) overlay request
              00292 ;
006E 00       00293 EFLAG$  DB      0               ;Flag E
006F 00       00294 FEMSK$  DB      0               ;Port FE mask
0070 00       00295         DC      2,0             ;Flags G-H
     00 
              00296 ;
              00297 ;       IFLAG$ - Assignments: (INTERNATIONAL)
              00298 ;        0 - FRENCH
              00299 ;        1 - GERMAN
              00300 ;        2 - SWISS
              00301 ;        3 -
              00302 ;        4 - 
              00303 ;        5 - 
              00304 ;        6 - Special DMP mode ON/OFF
              00305 ;        7 - '7' bit mode ON/OFF
              00306 ;
0072          00307 IFLAG$  EQU     $
              00308         IF      @FRENCH
              00309         DB      01000001B
              00310         ENDIF
              00311         IF      @GERMAN
              00312         DB      01000010B
              00313         ENDIF
              00314         IF      @USA
0072 00       00315         DB      0
              00316         ENDIF
0073 00       00317         DB      0               ;Flag J
              00318 ;
              00319 ;       KFLAG$ assignments:
              00320 ;        0 - BREAK latch
              00321 ;        1 - PAUSE latch
              00322 ;        2 - ENTER latch
              00323 ;        3 - reserved
              00324 ;        4 - reserved
              00325 ;        5 - CAPs lock
              00326 ;        6 - reserved
              00327 ;        7 - character in TYPE ahead
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00008 

'System low core assignments

              00328 ;
0074 00       00329 KFLAG$  DB      0               ;Keyboard flag
              00330 ;
              00331 ;       LFLAG$ assignments:
              00332 ;        0 - inhibit step rate question in FORMAT
              00333 ;        4 - inhibit 8" query in FLOPPY/DCT
              00334 ;        5 - inhibit # sides question in FORMAT
              00335 ;        6,7 - Reserved for IM 2 hardware
              00336 ;
0075 11       00337 LFLAG$  DB      00010001B       ;LDOS feature inhibit
              00338 ;
              00339 ;       MODOUT$ mask assignments:
              00340 ;        0 -
              00341 ;        1 - cassette motor on/off
              00342 ;        2 - mode select (0 = 80/64, 1 = 40/32)
              00343 ;        3 - enable alternate character set
              00344 ;        4 - enable external I/O
              00345 ;        5 - video wait states (0 = disable, 1 = enable)
              00346 ;        6 - clock speed ( 1 = 4 Mhz, 0 = 2 MHz)
              00347 ;        7 -
              00348 ;
              00349         IF      @INTL
              00350 MODOUT$ DB      70H             ;MODOUT international
              00351         ELSE
0076 78       00352 MODOUT$ DB      78H             ;MODOUT port image (FAST)
              00353         ENDIF
              00354 ;
              00355 ;
              00356 ;       NFLAG$ - Network flag$
              00357 ;        0 - Allow setting of file open bit in DIR
              00358 ;        1 / 5 - Reserved
              00359 ;        6 - Set if in Task Processor
              00360 ;        7 - Reserved
              00361 ;
0077 00       00362         DB      0               ;Inhibit open bit in DIR
              00363 ;
              00364 ;       OPREG$ memory management image port
              00365 ;        0 - SEL0 - Select map overlay bit 0
              00366 ;        1 - SEL1 - Select map overlay bit 1
              00367 ;        2 - 80/64 - 1 = 80 x 24
              00368 ;        3 - Inverse video
              00369 ;        4 - MBIT0 - memory map bit 0
              00370 ;        5 - MBIT1 - memory map bit 1
              00371 ;        6 - FXUPMEM - fix upper memory
              00372 ;        7 - PAGE - page 1K video RAM (set for 80x24)
              00373 ;
0078 87       00374 OPREG$  DB      87H             ;Memory management image
              00375 ;
              00376 ;       PFLAG$ - Printer flag
              00377 ;       7 = Printer spooler is paused
              00378 ;       0 - 6 = Reserved
              00379 ;
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00009 

'System low core assignments

0079 00       00380         DB      0
007A 00       00381         DB      0               ;QFLAG$
              00382 ;
              00383 ;       RFLAG$ - Retry init for FDC driver
              00384 ;
007B 08       00385 RFLAG$  DB      08              ;FDC retry count >=2
              00386 ;
              00387 ;       SFLAG$ assignments:
              00388 ;        0 - inhibit file open bit
              00389 ;        1 - set to 1 if bit-2 set & EXEC file opened
              00390 ;        2 - set by @RUN to permit load of EXEC file
              00391 ;        3 - SYSTEM (FAST)
              00392 ;        4 - BREAK key disabled
              00393 ;        5 - JCL active
              00394 ;        6 - force extended error messages
              00395 ;        7 - DEBUG to be turned on after load
              00396 ;
007C 08       00397 SFLAG$  DB      8               ;System flag (FAST)
              00398 ;
              00399 ;
              00400 ;       Machine TYPE assignment:
              00401 ;       All values are in decimal
              00402 ;
              00403 ;        2 = TRS-80 Model 2
              00404 ;        4 = TRS-80 Model 4
              00405 ;        5 = TRS-80 MODEL 4P
              00406 ;       12 = TRS-80 Model 12
              00407 ;       16 = TRS-80 Model 16
              00408 ;
              00409         IF      @MOD4
007D 04       00410 TFLAG$  DB      04              ;Model 4 assignment
              00411         ELSE
              00412         ERR     'Undefined machine TYPE for TFLAG'
              00413         ENDIF
007E 00       00414         DB      0               ;Flag U
              00415 ;
              00416 ;       Video FLAG$ assignments:
              00417 ;        0-3 - Set blink rate (1=fastest,7=slowest)
              00418 ;        4 - display CLOCK
              00419 ;        5 - cursor blink toggle bit
              00420 ;        6 - Inhibit blinking cursor (user)
              00421 ;        7 - Inhibit blinking cursor (system)
              00422 ;
007F 00       00423 VFLAG$  DB      0               ;Blink,Slow,No clock
              00424 ;
              00425 ;       WRINT$ - interrupt mask register
              00426 ;        0 - enable 1500 baud rising edge
              00427 ;        1 - enable 1500 baud falling edge
              00428 ;        2 - enable real time clock
              00429 ;        3 - enable I/O bus interrupts
              00430 ;        4 - enable RS-232 transmit interrupts
              00431 ;        5 - enable RS-232 receive data interrupts
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00010 

'System low core assignments

              00432 ;        6 - enable RS-232 error interrupt
              00433 ;
0080 04       00434 WRINT$  DB      4               ;WRINTMASK port image
0081 00       00435         DB      0               ;Flag x
              00436 ;
              00437 ;       Bits 0-7 indicate new style dating on drives 0-7
              00438 ;
0082 FF       00439 YFLAG$  DB      0FFH
0083 00       00440         DB      0               ;Z flag
              00441 ;
              00442 ;       Contents are high-order byte of SVC table
              00443 ;
0084 01       00444         DB      SVCTAB$<-8      ;MSB of SVC table
              00445 ;
              00446 ;       OSVER$ stores the operating system version
              00447 ;
0085 63       00448 OSVER$  DB      63H             ;OS version #
              00449 ;
              00450 ;       Vector for config initialization
              00451 ;
0086 C9       00452 @ICNFG  RET                     ;Initialization config
0087 0000     00453         DW      0
              00454 ;
              00455 ;       Chain vector for KI task processor
              00456 ;
0089 C9       00457 @KITSK  RET                     ;Keyboard task routine
008A 0000     00458         DW      0
              00459 ;
              00460 ;       System File Control Block for overlays
              00461 ;
008C 80       00462 SFCB$   DB      80H,0,0         ;System /SYS FCB
     00 00 
008F 001D     00463         DW      SBUFF$
0091 00       00464         DB      0
0092 0000     00465         DW      0,0,0,-1,0,-1,-1
     0000 0000 FFFF 0000 FFFF FFFF 
              00466 ;
              00467 ;       32-byte DEBUG save area
              00468 ;
00A0          00469 DBGSV$  DS      32
              00470 ;
              00471 ;       Job Control Language File Control Block
              00472 ;
00C0 00       00473 JFCB$   DC      3,0
     00 00 
00C3 001D     00474         DW      SBUFF$
00C5          00475         DS      27
              00476 ;
              00477 ;       System Command Line file control block
              00478 ;
00E0          00479 CFCB$   EQU     $               ;Command Interpreter FCB
00E0 43       00480 CFGFCB$ DB      'CONFIG/SYS.CCC:0',3
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00011 

'System low core assignments

     4F 4E 46 49 47 2F 53 59
     53 2E 43 43 43 3A 30 03
00F1          00481         DS      15
              00482 ;
              00483 ;       Page 1 - System Supervisor Call Table
              00484 ;
0100          00485 SVCTAB$ EQU     $
              00486         IFNE $,100H
              00487         ERR     'SVCTBL location violation'
              00488         ENDIF
              00489 ;
              00490 ;       Initial version
              00491 ;
2400          00492 MAXCOR$ EQU     2400H+START$
3000          00493 MINCOR$ EQU     3000H+START$
1300          00494         ORG     @BYTEIO
              00495 ;
              00496 ;       file positioning routines - MUST BE FIRST
              00497 ;
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00012 

'<File positioning subroutines

MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00013 

'<File positioning subroutines

1300          00500 *GET    FILPOSN:3
              00501 ;FILPOSN/ASM - LS-DOS 6.3
              00502 ;
              00503 ;       Entry for byte I/O from @GET & @PUT
              00504 ;
1300 DDE5     00505 BYTEIO  PUSH    IX
1302 D1       00506         POP     DE              ;Transfer DCB to DE
1303 CD6815   00507         CALL    CKOPEN@         ;Ck file open, save regs
1306 DDCB01FE 00508         SET     7,(IX+1)        ;Denote byte or LRec
130A 78       00509         LD      A,B             ;Get type code & test
130B FE02     00510         CP      2               ;For get/put
130D 79       00511         LD      A,C
130E 281F     00512         JR      Z,WRCHAR        ;Go on PUT
1310 3058     00513         JR      NC,IORETZ       ;Ignore if CTL
              00514 ;
              00515 ;       Get a byte from a file
              00516 ;
1312 CD9215   00517 RDCHAR  CALL    CKEOF1          ;Ck for end of file
1315 C0       00518         RET     NZ              ;Return if at end
1316 DDCB016E 00519         BIT     5,(IX+1)        ;If buffer not current,
131A C47913   00520         CALL    NZ,NSEC1        ;  read next sector
131D C0       00521         RET     NZ
131E CD1214   00522         CALL    BFRPOS          ;Pt to byte posn in bfr
1321 1A       00523         LD      A,(DE)          ;P/u the byte
1322 DD3405   00524         INC     (IX+5)          ;Inc NEXT ptr
1325 CC2A13   00525         CALL    Z,SET5          ;Set bit 5 if zero
1328 BF       00526         CP      A               ;Set Z flag--no error
1329 C9       00527         RET
              00528 ;
132A DDCB01EE 00529 SET5    SET     5,(IX+1)
132E C9       00530         RET
              00531 ;
              00532 ;       Write a byte to a file
              00533 ;
132F DDCB0076 00534 WRCHAR  BIT     6,(IX+0)        ;Prot level give write acc?
1333 CAC613   00535         JP      Z,RWRIT3        ;  go if not
1336 F5       00536         PUSH    AF              ;Save byte
1337 DDCB016E 00537         BIT     5,(IX+1)        ;Get next sector if
133B C46C13   00538         CALL    NZ,WRCH2        ;  buffer is not current
133E 2803     00539         JR      Z,WRCH1         ;Skip if read was ok
1340 E3       00540         EX      (SP),HL         ;Pop stack but keep
1341 E1       00541         POP     HL              ;  error # in AF
1342 C9       00542         RET
              00543 ;
1343 CD1214   00544 WRCH1   CALL    BFRPOS          ;Next bfr byte posn
1346 F1       00545         POP     AF
1347 12       00546         LD      (DE),A          ;Stuff the byte
1348 DDCB01E6 00547         SET     4,(IX+1)        ;Buffer contains updated data
134C DD3405   00548         INC     (IX+5)          ;Inc NEXT byte
134F F5       00549         PUSH    AF              ;Save Z or NZ flag
1350 CC2A13   00550         CALL    Z,SET5          ;Set bit 5 if offset 0
1353 CD9215   00551         CALL    CKEOF1          ;Check for EOF
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00014 

'<File positioning subroutines

1356 2006     00552         JR      NZ,ATEOFW       ;Go if there
1358 DDCB0176 00553         BIT     6,(IX+1)        ;Jump if EOF set to next
135C 2009     00554         JR      NZ,DNTSET       ;  only if at EOF
135E DD7108   00555 ATEOFW  LD      (IX+8),C        ;Set EOF
1361 DD750C   00556         LD      (IX+12),L
1364 DD740D   00557         LD      (IX+13),H
1367 F1       00558 DNTSET  POP     AF              ;Restore offset flag
1368 2846     00559         JR      Z,RWRIT1        ;Go to write sector if 00
136A AF       00560 IORETZ  XOR     A               ;Set Z flag--no error
136B C9       00561         RET
              00562 ;
              00563 ;       WRCHR needs the next sector - if UPDATE, ck EOF
              00564 ;
136C DD7E01   00565 WRCH2   LD      A,(IX+1)        ;Ck if UPD bit set
136F E607     00566         AND     7               ;Mask for prot level
1371 FE04     00567         CP      4               ;Check for UPD
1373 2004     00568         JR      NZ,NSEC1        ;Bypass EOF ck on > UPD
1375 CD9215   00569 NXTSECT CALL    CKEOF1          ;Ck for end of file
1378 C0       00570         RET     NZ              ;Can't extend in update mode
1379 DD7E01   00571 NSEC1   LD      A,(IX+1)        ;Read access?
137C E607     00572         AND     7
137E FE06     00573         CP      6
1380 3044     00574         JR      NC,RWRIT3       ;"Illegal access..." if not
1382 CDCB15   00575 NSEC2   CALL    IOREC           ;Calc cylinder/sector
1385 C0       00576         RET     NZ
1386 DDCB01AE 00577         RES     5,(IX+1)        ;Show buffer current
138A DD6E03   00578         LD      L,(IX+3)        ;P/u buffer address
138D DD6604   00579         LD      H,(IX+4)
1390 CDF419   00580         CALL    @RDSEC          ;Read the sector
1393 2803     00581         JR      Z,BUMPNRN       ;Go if no error
1395 FE06     00582         CP      6               ;Test for prot sector
1397 C0       00583         RET     NZ              ;Quit if error not 6
1398 DD340A   00584 BUMPNRN INC     (IX+10)         ;Inc the NRN ptr LSB
139B 2003     00585         JR      NZ,ZEROA@
139D DD340B   00586         INC     (IX+11)         ;  and MSB if necessary
              00587         IF      @BLD631
              00588 @SEEKSC:                        ;<631>
              00589         ENDIF
13A0 AF       00590 ZEROA@  XOR     A
13A1 C9       00591         RET
              00592 ;
              00593 ;       Repositioning needs to write out the buffer
              00594 ;
13A2 DD7E01   00595 RWRIT@  LD      A,(IX+1)
13A5 E690     00596         AND     90H             ;Test for non-sector i/o and
13A7 FE90     00597         CP      90H             ;  buffer contents changed
13A9 2805     00598         JR      Z,RWRIT1        ;Go if conditions true
13AB 18F3     00599         JR      ZEROA@          ;  else no need to write
13AD CD6815   00600 @RWRIT  CALL    CKOPEN@         ;Ck file open, save regs
13B0 CD0B14   00601 RWRIT1  CALL    GETNRN          ;P/u NRN
13B3 7C       00602         LD      A,H             ;Ignore if rewound
13B4 B5       00603         OR      L
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00015 

'<File positioning subroutines

13B5 C8       00604         RET     Z
13B6 2B       00605         DEC     HL              ;Dec & reset NRN
13B7 DD750A   00606         LD      (IX+10),L
13BA DD740B   00607         LD      (IX+11),H
              00608 ;
              00609 ;       Check access protection level
              00610 ;
13BD DD7E01   00611 RWRIT2  LD      A,(IX+1)        ;Get prot
13C0 E607     00612         AND     7
13C2 FE05     00613         CP      5               ;Update access or better?
13C4 3804     00614         JR      C,RWRIT4
13C6 3E25     00615 RWRIT3  LD      A,25H           ;Illegal access error code
13C8 B7       00616         OR      A               ;Return NZ
13C9 C9       00617         RET
              00618 ;
13CA E604     00619 RWRIT4  AND     4               ;If UPDATE access, then
13CC 2805     00620         JR      Z,RWRIT5        ;  can't extend if at EOF
13CE CD9215   00621         CALL    CKEOF1
13D1 20F3     00622         JR      NZ,RWRIT3       ;  so show "Illegal access...
13D3 CDCB15   00623 RWRIT5  CALL    IOREC           ;Calculate cylinder & sector
13D6 C0       00624         RET     NZ
13D7 DD6E03   00625         LD      L,(IX+3)        ;P/u buffer addr
13DA DD6604   00626         LD      H,(IX+4)
13DD DDCB01A6 00627         RES     4,(IX+1)        ;Altered buffer flag off
13E1 DDCB00D6 00628         SET     2,(IX+0)        ;Show modification done
13E5 CDE819   00629         CALL    @WRSEC          ;  for directory mod flag
13E8 C0       00630         RET     NZ
13E9 3E00     00631 VEROP   LD      A,0             ;Verify operation if set
13EB B7       00632         OR      A
13EC C4DC19   00633         CALL    NZ,@VRSEC       ;Verify if no write error
13EF C0       00634         RET     NZ              ;Return if wrt/ver error
13F0 CD9813   00635         CALL    BUMPNRN         ;Increment NRN
              00636 ;
              00637 ;       Check if ERN to be set to NRN
              00638 ;       Should be done for byte i/o, but not random i/o
              00639 ;
13F3 CD9215   00640         CALL    CKEOF1          ;Returns 0 if not at EOF
13F6 3D       00641         DEC     A               ;Set bit 6 if retcod=0
13F7 DDA601   00642         AND     (IX+1)          ;If IX+1, bit 6 set, then
13FA E640     00643         AND     40H             ;  don't update EOF unless at
13FC 20A2     00644         JR      NZ,ZEROA@       ;  or past the old EOF
13FE DD750C   00645 YESEOF  LD      (IX+12),L       ;Update ERN
1401 DD740D   00646         LD      (IX+13),H
1404 DDCB015E 00647         BIT     3,(IX+1)        ;Test if ending '!'
              00648         IF      @BLD631
1408 202C     00649         JR      NZ,WEOF1        ;<631>Upd dir if so
              00650         ELSE
              00651         JP      NZ,WEOF1        ;Upd dir if so
              00652         ENDIF
140A C9       00653         RET
              00654 ;
140B DD6E0A   00655 GETNRN  LD      L,(IX+10)       ;Xfer NRN to HL
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00016 

'<File positioning subroutines

140E DD660B   00656         LD      H,(IX+11)
1411 C9       00657         RET
              00658 ;
1412 DD7E05   00659 BFRPOS  LD      A,(IX+5)        ;P/u byte offset in buffer
1415 DD8603   00660         ADD     A,(IX+3)        ;Add to buffer lsb
1418 5F       00661         LD      E,A
1419 DD7E04   00662         LD      A,(IX+4)        ;  and adjust buffer MSB
141C CE00     00663         ADC     A,0             ;  if needed
141E 57       00664         LD      D,A             ;Return DE = posn
141F C9       00665         RET
              00666         IF      @BLD631
              00667 ;<631>
              00668 ;<631>  Return formatted date, HL => user buffer
              00669 ;<631>
1420 CDA807   00670 @DATE   CALL    DATELO$         ;<631>Call existing date code in LOWCORE
1423 E5       00671         PUSH    HL              ;<631>
1424 2B       00672         DEC     HL              ;<631>
1425 2B       00673         DEC     HL              ;<631>
1426 7E       00674         LD      A,(HL)          ;<631>
1427 FE3A     00675         CP      ':'             ;<631>Test for decade overflow
1429 3803     00676         JR      C,DATE1         ;<631>
142B D60A     00677         SUB     0AH             ;<631>
142D 77       00678         LD      (HL),A          ;<631>
142E E1       00679 DATE1   POP     HL              ;<631>
142F C9       00680         RET                     ;<631>
              00681         ELSE
              00682 ;
              00683 ;       Entry to seek next record of a file
              00684 ;
              00685 @SEEKSC CALL    CKOPEN@         ;Link to FCB & ck if open
              00686         CALL    CKEOF1          ;Ensure not > EOF
              00687         CALL    Z,IOREC         ;Get track/sector data
              00688         RET     NZ              ;Back on I/O error
              00689         CALL    @SEEK           ;Issue seek to drive
              00690         XOR     A               ;Ignore seek errors here
              00691         RET
              00692         ENDIF
              00693         IF      @BLD631
              00694 ;
              00695 ;       Entry to Write an end-of-file mark
              00696 ;<631>  This routine relocated here to allow more relative branch references.
              00697 ;
1430 CD6815   00698 @WEOF   CALL    CKOPEN@
1433 CDA213   00699         CALL    RWRIT@          ;Write buffer if needed
1436 DD4607   00700 WEOF1   LD      B,(IX+7)        ;P/u DEC of FPDE
1439 DD4E06   00701         LD      C,(IX+6)        ;P/u drive #
143C CDBB18   00702         CALL    @DIRRD          ;Read file's dir record
143F C0       00703         RET     NZ              ;Back if read error
1440 2C       00704         INC     L               ;Pt to ERN offset
1441 2C       00705         INC     L
1442 2C       00706         INC     L
1443 DD7E08   00707         LD      A,(IX+8)        ;P/u EOF offset
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00017 

'<File positioning subroutines

1446 77       00708         LD      (HL),A          ;Put in direc
1447 111100   00709         LD      DE,17           ;Pt to EOF in dir
144A 19       00710         ADD     HL,DE
144B DD7E0C   00711         LD      A,(IX+12)       ;P/u lo EOF
144E 77       00712         LD      (HL),A          ;Put EOF in direc
144F 23       00713         INC     HL
1450 DD7E0D   00714         LD      A,(IX+13)       ;P/u hi EOF
1453 77       00715         LD      (HL),A
1454 C30318   00716         JP      @DIRWR          ;Write direc and return
              00717         ENDIF
              00718 ;
              00719 ;       Entry to Skip record routine
              00720 ;
1457 CDDA14   00721 @SKIP   CALL    @LOC            ;Locate next record
145A 03       00722         INC     BC              ;Step past it
              00723 ;
              00724 ;       Entry to Position to record routine
              00725 ;
145B CD6815   00726 @POSN   CALL    CKOPEN@
145E DDCB01F6 00727         SET     6,(IX+1)        ;Upd eof only if NRN>EOF
1462 DDCB017E 00728         BIT     7,(IX+1)        ;Jump if sector i/o only
1466 281D     00729         JR      Z,POSN1
1468 60       00730         LD      H,B             ;Record ptr to HL
1469 69       00731         LD      L,C
146A DDB609   00732         OR      (IX+9)          ;P/u LRL
146D 2816     00733         JR      Z,POSN1         ;Skip nxt if LRL=256
146F CDC906   00734         CALL    @MUL16          ;Calc sector & offset
1472 44       00735         LD      B,H             ;Physical sector =>BC
1473 4D       00736         LD      C,L
1474 DD7705   00737         LD      (IX+5),A        ;Set byte ptr
1477 DDCB016E 00738         BIT     5,(IX+1)        ;Jump if buffer does not
147B 200B     00739         JR      NZ,POSN2        ;  contain current sector
147D CD0B14   00740         CALL    GETNRN          ;P/u the NRN
1480 37       00741         SCF
1481 ED42     00742         SBC     HL,BC
1483 2812     00743         JR      Z,$CKEOF        ;Pass on to CKEOF
1485 DD7705   00744 POSN1   LD      (IX+5),A        ;Offset in buffer
1488 C5       00745 POSN2   PUSH    BC
1489 CDA213   00746 POSN2A  CALL    RWRIT@          ;Write current if needed
148C C1       00747         POP     BC              ;  before moving
148D C0       00748         RET     NZ              ;Back on write error
148E DD710A   00749         LD      (IX+10),C       ;NRN
1491 DD700B   00750         LD      (IX+11),B
1494 CD2A13   00751         CALL    SET5            ;Show bfr does not
1497 C39215   00752 $CKEOF  JP      CKEOF1          ;  contain current sector
              00753 ;
              00754 ;       Entry to force a physical read
              00755 ;
149A CD6815   00756 @RREAD  CALL    CKOPEN@
149D 0E01     00757         LD      C,1             ;Cause ADJUST to bump
              00758 ;                               ;  NRN when called
149F CD0B14   00759 BKSP1   CALL    GETNRN          ;Get current record #
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00018 

'<File positioning subroutines

14A2 7C       00760         LD      A,H             ;If file is rewound,
14A3 B5       00761         OR      L               ;  then ignore the req
14A4 2815     00762         JR      Z,BKSP0         ;  & force OFFSET = 0
14A6 2B       00763         DEC     HL              ;Back up by 1
14A7 CDBA15   00764         CALL    ADJ2            ;RET if sector I/O only,
              00765                                 ;  else bump fwd if RREAD
              00766                                 ;  then back up if bit 5=0
14AA E5       00767         PUSH    HL              ;Will be popped into BC
14AB 18DC     00768         JR      POSN2A          ;Finish the job
              00769 ;
              00770 ;       Entry to backspace one logical record
              00771 ;
14AD CD6815   00772 @BKSP   CALL    CKOPEN@
14B0 4F       00773         LD      C,A             ;Keep ADJUST from bumping
14B1 DD4609   00774         LD      B,(IX+9)        ;P/u LRL
14B4 B0       00775         OR      B               ;Is it a 0
14B5 28E8     00776         JR      Z,BKSP1         ;Go if so
14B7 DD7E05   00777         LD      A,(IX+5)        ;P/u next byte pointer
14BA 90       00778         SUB     B               ;Sub one record length
14BB DD7705   00779 BKSP0   LD      (IX+5),A
14BE 38DF     00780         JR      C,BKSP1         ;Go if crossed sec bdry
14C0 AF       00781         XOR     A               ;  else all done
14C1 C9       00782         RET
              00783 ;
              00784 ;       Entry to Rewind to beginning
              00785 ;
14C2 CD6815   00786 @REW    CALL    CKOPEN@
14C5 47       00787         LD      B,A             ;Zero NRN
14C6 4F       00788         LD      C,A
14C7 18BC     00789         JR      POSN1           ;Will also zero offset
              00790 ;
              00791 ;       Entry to Position to end-of-file
              00792 ;
14C9 CD6815   00793 @PEOF   CALL    CKOPEN@
14CC DD4E0C   00794         LD      C,(IX+12)       ;ERN to BC
14CF DD460D   00795         LD      B,(IX+13)
14D2 DDB608   00796         OR      (IX+8)          ;P/u EOF byte
14D5 28AE     00797         JR      Z,POSN1         ;Go if full sector
14D7 0B       00798         DEC     BC              ;Point to last rec
14D8 18AB     00799         JR      POSN1           ;Use POSN to get end
              00800 ;
              00801 ;       Entry to Locate current record number
              00802 ;
14DA CD6815   00803 @LOC    CALL    CKOPEN@
14DD CD0B14   00804         CALL    GETNRN          ;P/u NRN
14E0 CDB715   00805         CALL    ADJUST          ;Get offset and adj NRN
14E3 DD5E09   00806 LOC1    LD      E,(IX+9)        ;P/u LRL
14E6 7B       00807         LD      A,E             ;Test LRL for zero
14E7 B7       00808         OR      A               ;If zero, then give NRN
14E8 2816     00809         JR      Z,LOC3          ;LRL=0, NRN is correct
14EA 0C       00810         INC     C               ;If offset is zero,
14EB 0D       00811         DEC     C               ;  then it's at 256,
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00019 

'<File positioning subroutines

14EC 2801     00812         JR      Z,LOC2          ;  and we don't dec NRN
14EE 2B       00813         DEC     HL
              00814 ;
              00815 ;       Divide the three byte pointer (HLC) by the LRL
              00816 ;
14EF CDE306   00817 LOC2    CALL    @DIV16          ;Divide (NRN-1)/LRL
14F2 45       00818         LD      B,L             ;Save high order result
14F3 54       00819         LD      D,H             ;Save possible overflow
14F4 67       00820         LD      H,A             ;Prepare 2nd dividend
14F5 69       00821         LD      L,C             ;P/u low order dividend
14F6 7B       00822         LD      A,E             ;P/u LRL divisor again
14F7 CDE306   00823         CALL    @DIV16
14FA 60       00824         LD      H,B             ;Xfer high order result
14FB B7       00825         OR      A               ;If remainder, we have a
14FC 2801     00826         JR      Z,$+3           ;  partial record to round
14FE 23       00827         INC     HL              ;  up to next record #
14FF 7A       00828         LD      A,D             ;Xfer possible overflow
1500 C1       00829 LOC3    POP     BC              ;Pop RESTREG return adr
1501 E3       00830         EX      (SP),HL         ;Exchange value with BC
1502 C5       00831         PUSH    BC              ;Restore RESTREG
              00832 ;
              00833         IF      @MOD4
1503          00834 ORARET@ EQU     $
              00835         ENDIF
1503 B7       00836         OR      A
1504 C9       00837         RET
              00838 ;
              00839 ;       Entry to Locate the end-of-file record
              00840 ;
1505 CD6815   00841 @LOF    CALL    CKOPEN@
1508 DD6E0C   00842         LD      L,(IX+12)       ;P/u ERN
150B DD660D   00843         LD      H,(IX+13)
150E DD4E08   00844         LD      C,(IX+8)        ;EOF byte
1511 18D0     00845         JR      LOC1            ;Handle all LRLs
              00846         IF      @BLD631
              00847 ;<631>  @WEOF has been relocated above @SKIP in 6.3.1
              00848         ELSE
              00849 ;
              00850 ;       Entry to Write an end-of-file mark
              00851 ;
              00852 @WEOF   CALL    CKOPEN@
              00853         CALL    RWRIT@          ;Write buffer if needed
              00854 WEOF1   LD      B,(IX+7)        ;P/u DEC of FPDE
              00855         LD      C,(IX+6)        ;P/u drive #
              00856         CALL    @DIRRD          ;Read file's dir record
              00857         RET     NZ              ;Back if read error
              00858         INC     L               ;Pt to ERN offset
              00859         INC     L
              00860         INC     L
              00861         LD      A,(IX+8)        ;P/u EOF offset
              00862         LD      (HL),A          ;Put in direc
              00863         LD      DE,17           ;Pt to EOF in dir
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00020 

'<File positioning subroutines

              00864         ADD     HL,DE
              00865         LD      A,(IX+12)       ;P/u lo EOF
              00866         LD      (HL),A          ;Put EOF in direc
              00867         INC     HL
              00868         LD      A,(IX+13)       ;P/u hi EOF
              00869         LD      (HL),A
              00870         JP      @DIRWR          ;Write direc and return
              00871         ENDIF
              00872 ;
              00873 ;       Entry to Read a record
              00874 ;
1513 CD6815   00875 @READ   CALL    CKOPEN@
1516 E5       00876         PUSH    HL
1517 CDA213   00877         CALL    RWRIT@          ;Write buffer if needed
151A E1       00878         POP     HL
151B C0       00879         RET     NZ              ;Back on write error
151C DD4609   00880         LD      B,(IX+9)        ;P/u LRL
151F 78       00881         LD      A,B             ;If LRL=256, just
1520 B7       00882         OR      A
1521 CA7513   00883         JP      Z,NXTSECT       ;  get the next sector
1524 E5       00884 RDREC   PUSH    HL              ;Save buffer posn
1525 C5       00885         PUSH    BC              ;Save LRL
1526 CD1213   00886         CALL    RDCHAR          ;Read next byte
1529 C1       00887         POP     BC
152A E1       00888         POP     HL
152B C0       00889         RET     NZ              ;Back on read error
152C 77       00890         LD      (HL),A          ;Put char into buffer
152D 23       00891         INC     HL              ;Bump buffer ptr
152E 10F4     00892         DJNZ    RDREC           ;Loop for entire record
1530 C9       00893         RET
              00894 ;
              00895 ;       Entry to Write a record
              00896 ;
1531 CD6815   00897 @WRITE  CALL    CKOPEN@
1534 32EA13   00898 WRIT1   LD      (VEROP+1),A     ;Turn on/off verify
1537 DD4609   00899         LD      B,(IX+9)        ;P/u LRL
153A 78       00900         LD      A,B             ;Bypass if LRL=256
153B B7       00901         OR      A
153C CABD13   00902         JP      Z,RWRIT2
153F E5       00903         PUSH    HL              ;Save some FCB values
1540 DD6605   00904         LD      H,(IX+5)        ;P/u buffer offset loc
1543 DD6E08   00905         LD      L,(IX+8)        ;P/U EOF offset byte
1546 E3       00906         EX      (SP),HL         ;Put values on stack
              00907                                 ;  and recover HL
1547 7E       00908 WRREC   LD      A,(HL)          ;Pass the logical record
1548 23       00909         INC     HL              ;  to the writing routine
1549 E5       00910         PUSH    HL              ;  byte by byte
154A C5       00911         PUSH    BC
154B CD2F13   00912         CALL    WRCHAR
154E C1       00913         POP     BC
154F E1       00914         POP     HL
1550 2005     00915         JR      NZ,WRERROR      ;Exit and fix FCB
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00021 

'<File positioning subroutines

1552 10F3     00916         DJNZ    WRREC           ;Loop for entire record
1554 E3       00917         EX      (SP),HL         ;Remove stored FCB info
1555 E1       00918         POP     HL              ;Recover HL
1556 C9       00919         RET
1557 E3       00920 WRERROR EX      (SP),HL         ;Get FCB Values
1558 DD7405   00921         LD      (IX+5),H        ;  and put them back
155B DD7508   00922         LD      (IX+8),L
155E E1       00923         POP     HL              ;Restore HL
155F C9       00924         RET                     ;Go back with error
              00925 ;
              00926 ;       Entry to Verify after write of a record
              00927 ;
1560 CD6815   00928 @VER    CALL    CKOPEN@
1563 3C       00929         INC     A               ;Set verify byte
1564 18CE     00930         JR      WRIT1
1566 37       00931 LNKFCB@ SCF                     ;Init to force file open
1567 D2       00932         DB      0D2H            ;  test by JP NC,aaaa
1568 1A       00933 CKOPEN@ LD      A,(DE)          ;Ignore if from LNKFCB
1569 07       00934         RLCA                    ;Test hi bit of FCB
156A E3       00935         EX      (SP),HL
156B 222600   00936         LD      (JRET$),HL      ;Save ret
156E ED532400 00937         LD      (JDCB$),DE      ;Save DCB
1572 E3       00938         EX      (SP),HL
1573 300F     00939         JR      NC,NOTOPEN      ;Go if not an open FCB
1575 F1       00940         POP     AF              ;Get return
1576 D5       00941         PUSH    DE              ;Dcb addr to IX
1577 DDE3     00942         EX      (SP),IX
1579 E5       00943         PUSH    HL              ;Save regs
157A D5       00944         PUSH    DE
157B C5       00945         PUSH    BC
157C E5       00946         PUSH    HL              ;Estab ret
157D 218915   00947         LD      HL,RESTREG      ;  to restore registers
1580 E3       00948         EX      (SP),HL
1581 F5       00949         PUSH    AF              ;Put back ret
1582 AF       00950         XOR     A
1583 C9       00951         RET                     ;Go back
              00952 ;
1584 F1       00953 NOTOPEN POP     AF
1585 3E26     00954         LD      A,26H           ;File not open
1587 B7       00955         OR      A
1588 C9       00956         RET
              00957 ;
1589 C1       00958 RESTREG POP     BC              ;Pop back registers save
158A D1       00959         POP     DE              ;  in CKOPEN@
158B E1       00960         POP     HL
158C DDE1     00961         POP     IX
158E C9       00962         RET
              00963 ;
              00964 ;       Entry to Check if at end-of-file
              00965 ;
158F CD6815   00966 @CKEOF  CALL    CKOPEN@
1592 CD0B14   00967 CKEOF1  CALL    GETNRN          ;P/U NRN into HL
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00022 

'<File positioning subroutines

1595 E5       00968         PUSH    HL              ;Save un-adjusted NRN
1596 CDB715   00969         CALL    ADJUST          ;Adjust for special cases
1599 7C       00970         LD      A,H             ;Compare hi byte
159A DDBE0D   00971         CP      (IX+13)
159D 200E     00972         JR      NZ,CKEOF2       ;Go if not equal
159F 7D       00973         LD      A,L             ;Compare lo byte
15A0 DDBE0C   00974         CP      (IX+12)
15A3 2008     00975         JR      NZ,CKEOF2       ;Go if not equal
15A5 0D       00976         DEC     C               ;Adjust for 00=256
15A6 DD7E08   00977         LD      A,(IX+8)        ;Compare offset byte
15A9 3D       00978         DEC     A
15AA 91       00979         SUB     C
15AB 3F       00980         CCF
15AC 03       00981         INC     BC              ;Restore old C value
15AD E1       00982 CKEOF2  POP     HL              ;Restore unadjusted NRN
15AE 3E1D     00983         LD      A,1DH           ;Rec # out of range code
15B0 2002     00984         JR      NZ,CKEOF3       ;Go if not at EOF
15B2 3D       00985         DEC     A               ;X'1C'=EOF encountered
15B3 C9       00986         RET                     ;Return with NZ flag
15B4 D0       00987 CKEOF3  RET     NC              ;Return with error
15B5 AF       00988         XOR     A               ;No error
15B6 C9       00989         RET
              00990 ;
              00991 ;       File positioning adjustment routines
              00992 ;
15B7          00993 ADJUST  EQU     $               ;Entry from @CKEOF & @LOC
15B7 DD4E05   00994         LD      C,(IX+5)        ;Pick up offset
15BA          00995 ADJ2    EQU     $               ;Entry from @BKSP/@RREAD
15BA DDCB017E 00996         BIT     7,(IX+1)        ;Sector I/O only?
15BE C8       00997         RET     Z               ;No adjustment if so
15BF 79       00998         LD      A,C             ;Offset =0? (or "RREAD?")
15C0 B7       00999         OR      A
15C1 2801     01000         JR      Z,$+3           ;Go if zero
15C3 23       01001         INC     HL              ;Adjust
15C4 DDCB016E 01002         BIT     5,(IX+1)        ;Check magic bit
15C8 C0       01003         RET     NZ              ;Go if set
15C9 2B       01004         DEC     HL              ;Adjust
15CA C9       01005         RET
              01006 ;
              01007 ;       Calculate the cylinder/sector of needed record
              01008 ;
15CB CD0B14   01009 IOREC   CALL    GETNRN          ;P/u record number
15CE CD261A   01010         CALL    @DCTBYT-5       ;Get # of sectors/gran
15D1 E61F     01011         AND     1FH
15D3 3C       01012         INC     A
15D4 CDE306   01013         CALL    @DIV16          ;By # of sectors/gran
15D7 326016   01014         LD      (CALS5+1),A     ;Sv rmndr (sector offset)
15DA DDE5     01015         PUSH    IX              ;Xfer fcb to HL
15DC E3       01016         EX      (SP),HL
15DD 010E00   01017         LD      BC,14           ;Pt to 1st extent info
15E0 09       01018         ADD     HL,BC
15E1 C1       01019         POP     BC              ;Pop gran ptr HL into BC
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00023 

'<File positioning subroutines

15E2 3E05     01020         LD      A,5             ;Init to ck 4 extents
15E4 110000   01021         LD      DE,0            ;  & extended FXDE ptr
15E7 F5       01022 GREC1   PUSH    AF
15E8 7E       01023         LD      A,(HL)          ;P/u starting cyl byte
15E9 23       01024         INC     HL              ;  & bypass if FF
15EA 3C       01025         INC     A
15EB 280B     01026         JR      Z,GREC2
15ED E5       01027         PUSH    HL              ;Xfer the # of grans up
15EE 62       01028         LD      H,D             ;  to but not including
15EF 6B       01029         LD      L,E             ;  this extent into HL
15F0 AF       01030         XOR     A               ;Sub gran pointer from
15F1 ED42     01031         SBC     HL,BC           ;  cumulative figure & go
15F3 380E     01032         JR      C,GREC3         ;  if not in previous ext
15F5 E1       01033         POP     HL
15F6 2829     01034         JR      Z,CALCSEC
15F8 23       01035 GREC2   INC     HL
15F9 F1       01036         POP     AF
15FA 3D       01037         DEC     A
15FB 2819     01038         JR      Z,GREC4         ;Jump when all quads c'kd
15FD 5E       01039         LD      E,(HL)          ;P/u cumulative # grans
15FE 23       01040         INC     HL              ;  up to but not
15FF 56       01041         LD      D,(HL)          ;  including this extent
1600 23       01042         INC     HL
1601 18E4     01043         JR      GREC1
1603 24       01044 GREC3   INC     H               ;Within 256 grans?
1604 7D       01045         LD      A,L             ;Xfer lo-order difference
1605 E1       01046         POP     HL              ;Rcvr # of contig grans
              01047 ;                               ;  in this extent
1606 20F0     01048         JR      NZ,GREC2        ;Go if not within 256
1608 D5       01049         PUSH    DE              ;Save cumulative count 
1609 5F       01050         LD      E,A             ;Xfer gran dif (neg)
160A 7E       01051         LD      A,(HL)          ;P/u # of grans
160B E61F     01052         AND     1FH             ;  in this extent
160D 83       01053         ADD     A,E             ;Add to negative diff
160E 7B       01054         LD      A,E             ;Put neg diff into A
160F D1       01055         POP     DE
1610 30E6     01056         JR      NC,GREC2        ;Go if not in this extent
1612 ED44     01057         NEG                     ;Is in this extent, make
1614 180B     01058         JR      CALCSEC         ;  diff positive & use it
              01059 ;
              01060 ;       All current quads checked - Need directory info
              01061 ;
              01062 GREC4
1616 CD6416   01063         CALL    ALLOC           ;Get # of grans
1619 C0       01064         RET     NZ              ;  into the extent
161A 325016   01065         LD      (CALS4+1),A     ;  or error RET
161D 302A     01066         JR      NC,CALS3        ;Jp if record in 1st ext
161F 181F     01067         JR      CALS1           ;  else jp if in another
              01068 ;
              01069 ;       Calc sector in gran
              01070 ;
1621 325016   01071 CALCSEC LD      (CALS4+1),A     ;Stuff # grans into
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00024 

'<File positioning subroutines

1624 46       01072         LD      B,(HL)          ;  this extent
1625 2B       01073         DEC     HL              ;P/u # contig grans &
1626 4E       01074         LD      C,(HL)          ;  rel start & start cyl
1627 23       01075         INC     HL
1628 F1       01076         POP     AF              ;Rcvr # of quad
1629 2F       01077         CPL
162A C604     01078         ADD     A,4
162C 3019     01079         JR      NC,CALS2        ;Jump if 1st ext or quad
162E 3C       01080         INC     A               ;If not 1st, set up to move
162F 07       01081         RLCA                    ;  matching quad to the
1630 07       01082         RLCA                    ;  first position by
1631 C5       01083         PUSH    BC              ;  shuffling the others up
1632 D5       01084         PUSH    DE
1633 4F       01085         LD      C,A             ;Get bytes to move
1634 0600     01086         LD      B,0
1636 EB       01087         EX      DE,HL           ;DE = top of last quad
1637 21FCFF   01088         LD      HL,-4
163A 19       01089         ADD     HL,DE           ;HL = top of next lower
163B EDB8     01090         LDDR                    ;Do the shuffle
163D EB       01091         EX      DE,HL
163E D1       01092         POP     DE
163F C1       01093         POP     BC
1640 70       01094 CALS1   LD      (HL),B          ;Move info on matching quad
1641 2B       01095         DEC     HL              ;  into position
1642 71       01096         LD      (HL),C
1643 2B       01097         DEC     HL
1644 72       01098         LD      (HL),D
1645 2B       01099         DEC     HL
1646 73       01100         LD      (HL),E
1647 60       01101 CALS2   LD      H,B             ;Xfer start & contig gran
1648 69       01102         LD      L,C             ;Xfer start cylinder
1649 7C       01103 CALS3   LD      A,H
164A 07       01104         RLCA                    ;P/u start gran on track
164B 07       01105         RLCA
164C 07       01106         RLCA
164D E607     01107         AND     7
164F C600     01108 CALS4   ADD     A,0             ;P/u # grans into extent
1651 CD1919   01109         CALL    RELCYL          ;Calc 1st relative cyl
1654 85       01110         ADD     A,L             ;Add starting cylinder
1655 57       01111         LD      D,A
1656 78       01112         LD      A,B             ;Rcvr # sectors/gran
1657 E61F     01113         AND     1FH
1659 3C       01114         INC     A
165A D5       01115         PUSH    DE              ;Calculate sector offset
165B CD0A19   01116         CALL    @MUL8           ;  into desired cylinder
165E D1       01117         POP     DE              ;  for desired granule
165F C600     01118 CALS5   ADD     A,0             ;P/u # of excess sectors
1661 5F       01119         LD      E,A             ;  over even gran & add
1662 AF       01120         XOR     A               ;  to granule sector
1663 C9       01121         RET
              01122 ;
              01123 ;       On entry, gran needed is in BC
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00025 

'<File positioning subroutines

              01124 ;
1664 CDAE16   01125 ALLOC   CALL    CYL_GRN         ;Find ext cntng gran
1667 C0       01126         RET     NZ              ;Ret on error
1668 E5       01127         PUSH    HL              ;Save starting cyl & gran
1669 60       01128         LD      H,B             ;Xfer granule needed to
166A 69       01129         LD      L,C             ;  HL then calculate how
166B AF       01130         XOR     A               ;  many grans into this
166C ED52     01131         SBC     HL,DE           ;  extent is the desired
166E 7D       01132         LD      A,L             ;  granule
166F 32A716   01133         LD      (ALL6+1),A      ;Stuff rel gran from
1672 E1       01134         POP     HL              ;  start of extent
1673 D5       01135         PUSH    DE              ;Save granule count
1674 DDE5     01136         PUSH    IX              ;  to extent
1676 E3       01137         EX      (SP),HL         ;FCB pointer to HL
1677 110E00   01138         LD      DE,14           ;Pt to 1st alloc in FCB
167A 19       01139         ADD     HL,DE
167B D1       01140         POP     DE              ;Pop starting cylinder
167C 0605     01141         LD      B,5             ;  to this extent
167E 7E       01142 ALL1    LD      A,(HL)          ;P/u a cyl
167F 23       01143         INC     HL              ;Does starting cyl of
1680 BB       01144         CP      E               ;  needed gran alloc
1681 2006     01145         JR      NZ,ALL2         ;  appear in this extent?
1683 7E       01146         LD      A,(HL)          ;Now see if needed gran is
1684 AA       01147         XOR     D               ;  in this extent field
1685 E6E0     01148         AND     0E0H            ;  by checking its starting gran
1687 2819     01149         JR      Z,ALL4
1689 05       01150 ALL2    DEC     B               ;Dec the count down loop
168A 2805     01151         JR      Z,ALL3          ;Done if no match
168C 23       01152         INC     HL              ;Go to next extent
168D 23       01153         INC     HL              ;  info in FCB
168E 23       01154         INC     HL
168F 18ED     01155         JR      ALL1
1691 D5       01156 ALL3    PUSH    DE              ;Save needed extent info
1692 EB       01157         EX      DE,HL           ;Set up to shuffle extent
1693 21FCFF   01158         LD      HL,-4           ;  info
1696 19       01159         ADD     HL,DE
1697 010C00   01160         LD      BC,12
169A EDB8     01161         LDDR
169C EB       01162         EX      DE,HL
169D C1       01163         POP     BC
169E AF       01164         XOR     A               ;Set Z, no error
169F 37       01165         SCF                     ;Set CF, extent not found
16A0 1803     01166         JR      ALL5
16A2 72       01167 ALL4    LD      (HL),D
16A3 EB       01168         EX      DE,HL
16A4 AF       01169         XOR     A               ;Set Z no error
16A5 D1       01170 ALL5    POP     DE
16A6 3E00     01171 ALL6    LD      A,0             ;# of grans into this ext
16A8 C9       01172         RET                     ;Where desired gran is
              01173 ;
              01174 ;       Extent is unused - need to allocate more space
              01175 ;
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00026 

'<File positioning subroutines

16A9 CDF216   01176 CG06    CALL    CG07            ;Try to allocate more
16AC C1       01177         POP     BC              ;Get back desired gran
16AD C0       01178         RET     NZ              ;Return on error
              01179                                 ;Look for gran again
              01180 ;
              01181 ;       Find extent containing desired granule
              01182 ;
16AE C5       01183 CYL_GRN PUSH    BC              ;Save desired gran #
16AF 110000   01184         LD      DE,0            ;Init gran counter
16B2 DD4607   01185         LD      B,(IX+7)        ;P/u DEC of file
16B5 78       01186 CG01    LD      A,B
16B6 32AC17   01187         LD      (STUFDEC+1),A   ;Stuff
16B9 DD4E06   01188         LD      C,(IX+6)        ;P/u drive for file
16BC CDBB18   01189         CALL    @DIRRD          ;Read its directory
16BF 011600   01190         LD      BC,22           ;Point to 1st extent
16C2 09       01191         ADD     HL,BC           ;  of its directory
16C3 EB       01192         EX      DE,HL           ;Gran count to HL
16C4 C1       01193         POP     BC              ;Restore desired gran
16C5 C0       01194         RET     NZ              ;Return on read error
16C6 1A       01195 CG02    LD      A,(DE)          ;Is this extent
16C7 FEFE     01196         CP      0FEH            ;  allocated?
16C9 301F     01197         JR      NC,CG05         ;Jump if it is not
16CB 13       01198         INC     DE              ;Point to allocation
16CC 1A       01199         LD      A,(DE)          ;P/u relative gran & #
16CD E5       01200         PUSH    HL              ;  of contiguous grans
16CE E61F     01201         AND     1FH             ;Keep contiguous grans
16D0 3C       01202         INC     A               ;  & bump for 0 offset
16D1 85       01203         ADD     A,L             ;Add to count in HL
16D2 6F       01204         LD      L,A
16D3 3001     01205         JR      NC,CG03
16D5 24       01206         INC     H               ;Bump hi order
16D6 E5       01207 CG03    PUSH    HL              ;Save gran count to
16D7 2B       01208         DEC     HL              ;  end of extent
16D8 AF       01209         XOR     A               ;Test if EOF is in this
16D9 ED42     01210         SBC     HL,BC           ;  allocation
16DB E1       01211         POP     HL
16DC 3004     01212         JR      NC,CG04         ;EOF not > this alloc
16DE 13       01213         INC     DE              ;Get rid of old
16DF F1       01214         POP     AF              ;  current quantity
16E0 18E4     01215         JR      CG02            ;Check next extent
              01216 ;
              01217 ;       The EOF is within this allocation. Recover
              01218 ;       the allocation data and exit
              01219 ;
16E2 E1       01220 CG04    POP     HL              ;P/u gran count to extent
16E3 EB       01221         EX      DE,HL           ;Gran count to DE
16E4 7E       01222         LD      A,(HL)          ;P/u granule data
16E5 2B       01223         DEC     HL
16E6 6E       01224         LD      L,(HL)          ;P/u starting cylinder
16E7 67       01225         LD      H,A
16E8 AF       01226         XOR     A
16E9 C9       01227         RET
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00027 

'<File positioning subroutines

              01228 ;
              01229 ;       This extent is 1) unused, or 2) FXDE pointer
              01230 ;       and the needed gran has not been found yet
              01231 ;
16EA C5       01232 CG05    PUSH    BC              ;Gran count to DE &
16EB EB       01233         EX      DE,HL           ;DIR ptr to HL
16EC 20BB     01234         JR      NZ,CG06         ;Jump if unused
16EE 23       01235         INC     HL              ;Point to DEC of FXDE
16EF 46       01236         LD      B,(HL)          ;P/u the DEC
16F0 18C3     01237         JR      CG01            ;  & loop
              01238 ;
              01239 ;       See if the drive has enough free space left
              01240 ;
16F2 C5       01241 CG07    PUSH    BC              ;Save needed gran
16F3 DD4E06   01242         LD      C,(IX+6)        ;P/u file's drive
16F6 CD7418   01243         CALL    @GATRD          ;Get GAT
16F9 C1       01244         POP     BC              ;Rcvr needed gran
16FA C0       01245         RET     NZ              ;Return if GAT error
16FB E5       01246         PUSH    HL
16FC 60       01247         LD      H,B             ;Xfer the requested
16FD 69       01248         LD      L,C             ;  gran to HL &
16FE AF       01249         XOR     A               ;  subtract current gran
16FF ED52     01250         SBC     HL,DE           ;Count to calculate how
1701 44       01251         LD      B,H             ;  many excess grans
1702 4D       01252         LD      C,L             ;  are needed
1703 03       01253         INC     BC
1704 D1       01254         POP     DE              ;Rcvr dir byte ptr
1705 13       01255         INC     DE              ;Pt to next DIR byte
1706 2623     01256         LD      H,DIRBUF$<-8    ;Start looking at TRK #1
1708 3A6A00   01257         LD      A,(AFLAG$)      ;P/u Search start CYL
170B 6F       01258         LD      L,A             ;  and put it in L
170C C5       01259         PUSH    BC              ;Save excess grans needed
170D 7B       01260         LD      A,E             ;Is this extent the 1st?
170E E61E     01261         AND     1EH             ;Jump if so, else we can
1710 FE16     01262         CP      16H             ;  use it for allocation
1712 2842     01263         JR      Z,CG14
1714 1D       01264         DEC     E               ;Backup to previous
1715 1D       01265         DEC     E               ;  extent
1716 1A       01266 CG12    LD      A,(DE)          ;P/u # of contig grans to
1717 E61F     01267         AND     1FH             ;  see if the last gran
1719 3C       01268         INC     A               ;  used can be extended
171A 4F       01269         LD      C,A             ;Is current # the max
171B FE20     01270         CP      20H             ;  an extent can hold?
171D 2820     01271         JR      Z,CG13          ;Jump if a full extent
171F 1A       01272         LD      A,(DE)          ;  (32 grans max) - else
1720 E6E0     01273         AND     0E0H            ;  p/u the relative
1722 07       01274         RLCA                    ;  granule offset
1723 07       01275         RLCA
1724 07       01276         RLCA
1725 81       01277         ADD     A,C             ;Add the # of contiguous
1726 D5       01278         PUSH    DE              ;  granules
1727 CD1919   01279         CALL    RELCYL          ;Calc relative cyl needed
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00028 

'<File positioning subroutines

172A 47       01280         LD      B,A             ;Save offset
172B 4B       01281         LD      C,E
172C D1       01282         POP     DE
172D 1B       01283         DEC     DE              ;Backup to starting cyl
172E 1A       01284         LD      A,(DE)
172F 13       01285         INC     DE              ;  & repoint to alloc byte
1730 80       01286         ADD     A,B             ;Add cyls used to
1731 6F       01287         LD      L,A             ;  starting cyl
1732 2623     01288         LD      H,DIRBUF$<-8    ;Is it less than max?
1734 FECB     01289         CP      0CBH
1736 3007     01290         JR      NC,CG13         ;Jump if too big
1738 79       01291         LD      A,C
1739 46       01292         LD      B,(HL)          ;P/u the cyl's GAT
173A CD5B18   01293         CALL    TSTBIT          ;Test if gran is free
173D 284B     01294         JR      Z,CG21          ;Bypass if free gran
              01295 ;
              01296 ;       The next gran cannot be used - get another extent
              01297 ;
173F 1C       01298 CG13    INC     E               ;Else point to next
1740 1C       01299         INC     E               ;  extent field
1741 7B       01300         LD      A,E
1742 E61E     01301         AND     1EH             ;Jump if not on the FXDE
1744 FE1E     01302         CP      1EH             ;  field, else we have to
1746 200E     01303         JR      NZ,CG14         ;  obtain an FXDE record
              01304 ;
              01305 ;       Last extent used up, get new dir rec for FXDE
              01306 ;
1748 CDA417   01307         CALL    CG23            ;Write curent GAT & HIT
174B C1       01308         POP     BC
174C C0       01309         RET     NZ              ;Ret if GAT/HIT error
174D C5       01310         PUSH    BC
174E CDAF17   01311         CALL    NEWHIT          ;Get new HIT for FXDE
1751 C1       01312         POP     BC
1752 C0       01313         RET     NZ              ;Loop to process
1753 C3AE16   01314         JP      CYL_GRN         ;  new extent
              01315 ;
              01316 ;       Extent is vacant - use it & get new allocation
              01317 ;
1756 CDFE18   01318 CG14    CALL    MAXCYL          ;Get highest # cyl
1759 326017   01319         LD      (CG17+1),A      ;Stuff highest cyl
175C 0602     01320         LD      B,2
175E 7D       01321 CG16    LD      A,L             ;Test last cyl used
175F FE00     01322 CG17    CP      0               ;P/u max cyl
1761 3007     01323         JR      NC,CG18
1763 7E       01324         LD      A,(HL)          ;P/u a GAT byte
1764 3C       01325         INC     A
1765 2010     01326         JR      NZ,CG19         ;Go if space in this cyl
1767 2C       01327         INC     L               ;  else bump to next one
1768 18F4     01328         JR      CG16            ;  & loop
176A 2E00     01329 CG18    LD      L,0             ;Now start from begin
176C 10F0     01330         DJNZ    CG16            ;  of disk & recheck
176E C1       01331         POP     BC
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00029 

'<File positioning subroutines

176F CDA417   01332         CALL    CG23            ;Write out GAT & HIT
1772 C0       01333         RET     NZ
1773 3E1B     01334         LD      A,1BH           ;"disk space full"
1775 B7       01335         OR      A
1776 C9       01336         RET
              01337 ;
              01338 ;       Found available space in cylinder
              01339 ;
1777 3EFF     01340 CG19    LD      A,0FFH          ;Set DIR extent to FF
1779 12       01341         LD      (DE),A
177A 0E00     01342         LD      C,0
177C 46       01343         LD      B,(HL)          ;P/u current GAT alloc
177D 79       01344 CG20    LD      A,C
177E CD5B18   01345         CALL    TSTBIT          ;Find a free gran
1781 2807     01346         JR      Z,CG21          ;  & jump when found
1783 1A       01347         LD      A,(DE)          ;  else advance starting
1784 C620     01348         ADD     A,20H           ;  rel gran value
1786 12       01349         LD      (DE),A
1787 0C       01350         INC     C               ;Bump pointer to test
1788 18F3     01351         JR      CG20            ;  next gran
              01352 ;
              01353 ;       Next gran in line is free - allocate it
              01354 ;
178A 79       01355 CG21    LD      A,C
178B CD6818   01356         CALL    SETBIT          ;Show it allocated
178E B6       01357         OR      (HL)
178F 77       01358         LD      (HL),A
1790 1D       01359         DEC     E               ;Backup to starting cyl
1791 1A       01360         LD      A,(DE)          ;Bump by one to see if
1792 3C       01361         INC     A               ;  this alloc is the 1st
1793 2002     01362         JR      NZ,CG22         ;  one for the extent &
1795 7D       01363         LD      A,L             ;  we have to set the
              01364                                 ;  starting cylinder
1796 12       01365         LD      (DE),A          ;Stuff starting cyl
1797 1C       01366 CG22    INC     E
1798 1A       01367         LD      A,(DE)          ;Add 1 to # of contiguous
1799 3C       01368         INC     A               ;  granules
179A 12       01369         LD      (DE),A
179B C1       01370         POP     BC              ;Decrement needed gran
179C 0B       01371         DEC     BC              ;  count since we just
179D C5       01372         PUSH    BC              ;  allocated one
179E 78       01373         LD      A,B             ;Loop if we need more
179F B1       01374         OR      C               ;  space allocated
17A0 C21617   01375         JP      NZ,CG12
17A3 C1       01376         POP     BC
17A4 DD4E06   01377 CG23    LD      C,(IX+6)        ;Else p/u the drive #
17A7 CD7518   01378         CALL    @GATWR          ;  & write out the GAT
17AA C0       01379         RET     NZ
17AB 0600     01380 STUFDEC LD      B,0             ;P/u DEC of FPDE
17AD 1854     01381         JR      @DIRWR
              01382 ;
              01383 ;       Get new HIT for FXDE
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00030 

'<File positioning subroutines

              01384 ;
17AF DD4E06   01385 NEWHIT  LD      C,(IX+6)        ;P/u drive #
17B2 CD9718   01386         CALL    @HITRD          ;Read the HIT
17B5 C0       01387         RET     NZ
17B6 DD7E07   01388         LD      A,(IX+7)        ;P/u FPDE DEC so 1st ck
17B9 E61F     01389         AND     1FH             ;  will be for next
17BB CD1F18   01390         CALL    @SCNHIT         ;  in line
17BE 3E1E     01391         LD      A,1EH           ;Init "full directory...
17C0 C0       01392         RET     NZ              ;Ret if no space
17C1 45       01393         LD      B,L             ;Set DEC for
17C2 7D       01394         LD      A,L             ;  directory read
17C3 320218   01395         LD      (NHIT3+1),A     ;Stuff new DEC from HIT
17C6 54       01396         LD      D,H
17C7 DD5E07   01397         LD      E,(IX+7)        ;P/u current DEC
17CA 1A       01398         LD      A,(DE)          ;Copy filespec hash code
17CB 77       01399         LD      (HL),A          ;  to new DEC
17CC CD9818   01400         CALL    @HITWR
17CF CCBB18   01401         CALL    Z,@DIRRD
17D2 C0       01402         RET     NZ
17D3 3690     01403         LD      (HL),90H        ;Show dir rec in use as
17D5 2C       01404         INC     L               ;  FXDE record
17D6 C5       01405         PUSH    BC              ;P/u DEC of FPDE &
17D7 3AAC17   01406         LD      A,(STUFDEC+1)   ;  stuff it into FXDE's
17DA 77       01407         LD      (HL),A          ;  DIR+1 to link back
17DB 2C       01408         INC     L
17DC 0614     01409         LD      B,20            ;Zero out 20 bytes
17DE 3600     01410 NHIT1   LD      (HL),0          ;  in the FXDE
17E0 2C       01411         INC     L
17E1 10FB     01412         DJNZ    NHIT1
17E3 E5       01413         PUSH    HL              ;Save ptr to 1st extent
17E4 060A     01414         LD      B,10            ;Init to X'FF' 10 bytes
17E6 36FF     01415 NHIT2   LD      (HL),0FFH       ;  or 5 extents
17E8 2C       01416         INC     L
17E9 10FB     01417         DJNZ    NHIT2
17EB D1       01418         POP     DE              ;Rcvr ptr to 1st extent
17EC 13       01419         INC     DE              ;Pt to allocation byte
17ED C1       01420         POP     BC
17EE CD0318   01421         CALL    @DIRWR          ;Write FXDE back to disk
17F1 C0       01422         RET     NZ              ;Return if error
17F2 3AAC17   01423         LD      A,(STUFDEC+1)   ;  else p/u DEC of FPDE
17F5 47       01424         LD      B,A
17F6 CDBB18   01425         CALL    @DIRRD          ;Read its directory
17F9 C0       01426         RET     NZ              ;  & return if error
17FA 7D       01427         LD      A,L
17FB C61E     01428         ADD     A,1EH           ;Point to FXDE posn
17FD 6F       01429         LD      L,A             ;  in FPDE
17FE 36FE     01430         LD      (HL),0FEH       ;Show link to FXDE
1800 2C       01431         INC     L
1801 3600     01432 NHIT3   LD      (HL),0          ;Show what's the FXDE DEC
              01433                                 ;  & write the DIR back
              01434 ;
              01435 ;       Routine to write a directory sector
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00031 

'<File positioning subroutines

              01436 ;       B => DEC of FPDE, C => logical drive number
              01437 ;       HL <= points to directory record in SBUFF$
              01438 ;
1803 CD0718   01439 @DIRWR  CALL    DIRWR           ;Permit two attempts
1806 C8       01440         RET     Z
1807 D5       01441 DIRWR   PUSH    DE              ;Save the reg
1808 CDCA18   01442         CALL    CALCDIR         ;Calc dir cyl
180B 2E00     01443         LD      L,0             ;Set buffer to start
180D CDEC19   01444         CALL    @WRSSC          ;Write the sector
1810 CCDC19   01445         CALL    Z,@VRSEC        ;Verify on no error
1813 D606     01446         SUB     6
1815 D1       01447         POP     DE
1816 C8       01448         RET     Z               ;Back on system sector
1817 FE09     01449         CP      0FH-6           ;WP error?
1819 3E12     01450         LD      A,18            ;Set dir write error
181B C0       01451         RET     NZ              ;  if not WP
181C D603     01452         SUB     3
181E C9       01453         RET
              01454 ;
              01455 ;       Find a spare HIT entry
              01456 ;
181F F5       01457 @SCNHIT PUSH    AF
1820 3E07     01458         LD      A,7             ;Get highest # sector
1822 CD2B1A   01459         CALL    @DCTBYT         ;  on a cylinder
1825 D5       01460         PUSH    DE              ;  into register E
1826 57       01461         LD      D,A
1827 E61F     01462         AND     1FH
1829 5F       01463         LD      E,A
182A 1C       01464         INC     E               ;& get number of heads
182B AA       01465         XOR     D               ;  into register A
182C 07       01466         RLCA
182D 07       01467         RLCA
182E 07       01468         RLCA
182F 3C       01469         INC     A
1830 CD0A19   01470         CALL    @MUL8           ;To calc sectors/cylinder
1833 CD3B19   01471         CALL    CKDBLBIT        ;Double if necessary
1836 D1       01472         POP     DE              ;Total sectors per cyl
1837 D602     01473         SUB     2               ;Reduce for GAT & HIT
1839 324D18   01474         LD      (NHIT7+1),A     ;# of directory sectors
183C F1       01475         POP     AF              ;Get DEC init entry
183D 6F       01476         LD      L,A
183E CD4918   01477         CALL    NHIT6           ;Ck if HIT slot is spare
1841 C8       01478         RET     Z               ;Return if it is spare
1842 2E01     01479         LD      L,1             ;Start at beginning
1844 2C       01480 NHIT5   INC     L
1845 2002     01481         JR      NZ,NHIT6
1847 B4       01482         OR      H
1848 C9       01483         RET
1849 7D       01484 NHIT6   LD      A,L
184A E61F     01485         AND     1FH
184C FE00     01486 NHIT7   CP      0
184E 7D       01487         LD      A,L
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00032 

'<File positioning subroutines

184F 3805     01488         JR      C,NHIT8
1851 F61F     01489         OR      1FH
1853 6F       01490         LD      L,A
1854 18EE     01491         JR      NHIT5
1856 7E       01492 NHIT8   LD      A,(HL)
1857 B7       01493         OR      A
1858 C8       01494         RET     Z
1859 18E9     01495         JR      NHIT5
              01496 ;
              01497 ;       Test if gran is free in GAT
              01498 ;
185B E607     01499 TSTBIT  AND     7               ;Get 0 to 7
185D 07       01500         RLCA                    ;Shift to match BIT n,
185E 07       01501         RLCA                    ;  opcode
185F 07       01502         RLCA
1860 F640     01503         OR      40H
1862 326618   01504         LD      (TBIT1+1),A     ;Modify BIT instruction
1865 CB40     01505 TBIT1   BIT     0,B
1867 C9       01506         RET
              01507 ;
              01508 ;       Set gran to allocated in GAT
              01509 ;
1868 07       01510 SETBIT  RLCA                    ;Shift to create opcode
1869 07       01511         RLCA                    ;  to match current bit
186A 07       01512         RLCA
186B F6C7     01513         OR      0C7H
186D 327218   01514         LD      (SBIT1+1),A     ;Create SET n, opcode
1870 AF       01515         XOR     A
1871 CBC7     01516 SBIT1   SET     0,A
1873 C9       01517         RET
              01518 ;
              01519 ;       Routine reads/writes the Granule Allocation Table
              01520 ;
1874 F6       01521 @GATRD  DB      0F6H            ;Set NZ for test
1875 AF       01522 @GATWR  XOR     A               ;Set Z for test
1876 D5       01523         PUSH    DE
1877 E5       01524         PUSH    HL
1878 F5       01525         PUSH    AF              ;Save flag for test
1879 CDF718   01526         CALL    @DIRCYL
187C 210023   01527         LD      HL,DIRBUF$
187F 5D       01528         LD      E,L             ;Set E to 0
1880 F1       01529         POP     AF              ;Rcvr flag for R/W
1881 2807     01530         JR      Z,GATRW1        ;Go if @GATWR
1883 CDD818   01531         CALL    @RDSSC
1886 3E14     01532         LD      A,14H           ;Init "GAT read error"
1888 180A     01533         JR      GATRW2
188A CDEC19   01534 GATRW1  CALL    @WRSSC          ;Protected sector write
188D CCDC19   01535         CALL    Z,@VRSEC        ;Verify if OK
1890 FE06     01536         CP      6               ;Protected sector?
1892 3E15     01537         LD      A,15H           ;Init "GAT write error"
1894 E1       01538 GATRW2  POP     HL
1895 D1       01539         POP     DE
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00033 

'<File positioning subroutines

1896 C9       01540         RET
              01541 ;
              01542 ;       Read or write the hash index table
              01543 ;
1897 F6       01544 @HITRD  DB      0F6H            ;Set NZ for test
1898 AF       01545 @HITWR  XOR     A               ;Set Z for test
1899 C5       01546         PUSH    BC
189A D5       01547         PUSH    DE
189B F5       01548         PUSH    AF              ;Save flag for test
189C CDF718   01549         CALL    @DIRCYL         ;D => directory cylinder
189F 1E01     01550         LD      E,1             ;E => HIT sector
18A1 21001D   01551         LD      HL,SBUFF$       ;HL => HIT buffer area
18A4 F1       01552         POP     AF              ;Rcvr flag for RD/WR
18A5 2807     01553         JR      Z,HITRW1        ;Go if @HITWR
18A7 CDD818   01554         CALL    @RDSSC          ;Read cyl D, sector E
18AA 3E16     01555         LD      A,22            ;Init "HIT read error"
18AC 180A     01556         JR      HITRW2
18AE CDEC19   01557 HITRW1  CALL    @WRSSC          ;Protected sector write
18B1 CCDC19   01558         CALL    Z,@VRSEC        ;Verify the write
18B4 FE06     01559         CP      6               ;Protected sector?
18B6 3E17     01560         LD      A,23            ;"HIT write error"
18B8 D1       01561 HITRW2  POP     DE              ;Message for other than
18B9 C1       01562         POP     BC              ;  attempt protected sector
18BA C9       01563         RET
              01564 ;
              01565 ;       Routine to read a directory sector
              01566 ;       B => DEC of FPDE, C => logical drive number
              01567 ;       HL <= points to directory record in SBUFF$
              01568 ;
18BB D5       01569 @DIRRD  PUSH    DE
18BC CDCA18   01570         CALL    CALCDIR         ;Set HL to SBUFF$
18BF E5       01571         PUSH    HL
18C0 2E00     01572         LD      L,0             ;Start of bfr
18C2 CDD818   01573         CALL    @RDSSC          ;Read it
18C5 E1       01574         POP     HL
18C6 3E11     01575         LD      A,17            ;Init to dir read err
18C8 D1       01576         POP     DE
18C9 C9       01577         RET
              01578 ;
              01579 ;       Routine to get directory access data
              01580 ;       B => DEC
              01581 ;       DE <= cylinder and sector needed
              01582 ;       HL <= pointer to directory record in SBUFF$
              01583 ;
18CA CDF718   01584 CALCDIR CALL    @DIRCYL         ;Get directory cyl in D
18CD 78       01585         LD      A,B             ;Calculate record start
18CE E6E0     01586         AND     0E0H            ;  from the DEC
18D0 6F       01587         LD      L,A
18D1 261D     01588         LD      H,SBUFF$<-8     ;Point to buffer start
18D3 A8       01589         XOR     B               ;Calculate directory
18D4 C602     01590         ADD     A,2             ;  sector needed
18D6 5F       01591         LD      E,A
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00034 

'<File positioning subroutines

18D7 C9       01592         RET
              01593 ;
              01594 ;       Read system sector, D=Track, E=Sector, HL=Buffer
              01595 ;
18D8 CDF118   01596 @RDSSC  CALL    READIR
18DB C8       01597         RET     Z
18DC D5       01598         PUSH    DE
18DD 110100   01599         LD      DE,1            ;Pt to tk 0, sec 1
18E0 CDF419   01600         CALL    @RDSEC          ;Read to find dir cyl
18E3 D1       01601         POP     DE
18E4 C0       01602         RET     NZ
18E5 E5       01603         PUSH    HL
18E6 23       01604         INC     HL              ;Pt to dir tk #
18E7 23       01605         INC     HL
18E8 56       01606         LD      D,(HL)          ;P/u dir tk fm boot
18E9 2609     01607         LD      H,9             ;Update memory table
18EB CD341A   01608         CALL    DCTFLD@
18EE 6F       01609         LD      L,A
18EF 72       01610         LD      (HL),D
18F0 E1       01611         POP     HL
18F1 CDF419   01612 READIR  CALL    @RDSEC          ;Retry dir read
18F4 D606     01613         SUB     6               ;Test protected
18F6 C9       01614         RET
              01615 ;
18F7 3E09     01616 @DIRCYL LD      A,9
18F9 CD2B1A   01617         CALL    @DCTBYT         ;Get the dir cylinder
18FC 57       01618         LD      D,A
18FD C9       01619         RET
              01620 ;
18FE 3E06     01621 MAXCYL  LD      A,6
1900 C5       01622         PUSH    BC
1901 DD4E06   01623         LD      C,(IX+6)
1904 CD2B1A   01624         CALL    @DCTBYT         ;Get highest # cyl
1907 3C       01625         INC     A               ;Adjust for zero offset
1908 C1       01626         POP     BC
1909 C9       01627         RET
              01628 ;
              01629 ;       Multiply register E by register A
              01630 ;
190A C5       01631 @MUL8   PUSH    BC              ;Mult A x E
190B 57       01632         LD      D,A
190C AF       01633         XOR     A
190D 0608     01634         LD      B,8
190F 87       01635 MEA1    ADD     A,A
1910 CB23     01636         SLA     E
1912 3001     01637         JR      NC,MEA2
1914 82       01638         ADD     A,D
1915 10F8     01639 MEA2    DJNZ    MEA1
1917 C1       01640         POP     BC
1918 C9       01641         RET
              01642 ;
              01643 ;       Calculate relative cylinder for granule needed
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00035 

'<File positioning subroutines

              01644 ;
1919 5F       01645 RELCYL  LD      E,A
191A CD261A   01646         CALL    @DCTBYT-5       ;Get # of grans/track
191D 47       01647         LD      B,A             ;Hang on to this
191E 07       01648         RLCA
191F 07       01649         RLCA
1920 07       01650         RLCA
1921 E607     01651         AND     7
1923 3C       01652         INC     A               ;Adj for 0 offset
1924 CD3B19   01653         CALL    CKDBLBIT
              01654 ;
              01655 ;       Divide register E by register A
              01656 ;
1927 C5       01657 @DIV8   PUSH    BC
1928 4F       01658         LD      C,A
1929 0608     01659         LD      B,8
192B AF       01660         XOR     A
192C CB23     01661 DEA1    SLA     E
192E 17       01662         RLA
192F B9       01663         CP      C
1930 3802     01664         JR      C,DEA2
1932 91       01665         SUB     C
1933 1C       01666         INC     E
1934 10F6     01667 DEA2    DJNZ    DEA1
1936 4F       01668         LD      C,A
1937 7B       01669         LD      A,E
1938 59       01670         LD      E,C
1939 C1       01671         POP     BC
193A C9       01672         RET
              01673 ;
              01674 ;       Routine to double the A register if DBL bit is set
              01675 ;
              01676 CKDBLBIT
193B 57       01677         LD      D,A             ;Adjust for 2-sided &
193C 3E04     01678         LD      A,4             ;  calculate # of cyls
193E CD2B1A   01679         CALL    @DCTBYT
1941 CB6F     01680         BIT     5,A             ;Test if 2-sided
1943 7A       01681         LD      A,D
1944 2801     01682         JR      Z,$+3           ;Double the grans if 2
1946 87       01683         ADD     A,A             ;  & fall thru to DIV8
1947 C9       01684         RET
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00036 

'<File positioning subroutines

1948          01686 CORE$   DEFL    $
F80D          01687         ORG     CRTBGN$+13
              01688         IF      @BLD631
F80D 4C       01689         DB      'LS-DOS 06.03.01'       ;<631>
     53 2D 44 4F 53 20 30 36
     2E 30 33 2E 30 31 
              01690         ELSE
              01691         DB      'LS-DOS 06.03.00'
              01692         ENDIF
              01693         IF      @USA
F81C 20       01694         DB      ' '
              01695         ENDIF
              01696         IF      @GERMAN
              01697         DB      'D'
              01698         ENDIF
              01699         IF      @FRENCH
              01700         DB      'F'
              01701         ENDIF
              01702         IF      @BLD631
F81D 2D       01703         DB      '- Copyright 1986/90 '  ;<631>
     20 43 6F 70 79 72 69 67
     68 74 20 31 39 38 36 2F
     39 30 20 
F831 4D       01704         DB      'MISOSYS, Inc.    '     ;<631>
     49 53 4F 53 59 53 2C 20
     49 6E 63 2E 20 20 20 20
              01705         ELSE
              01706         DB      '- Copyright 1986 '
              01707         DB      'Logical Systems Inc.'
              01708         ENDIF
F85E          01709         ORG     CRTBGN$+80+14
F85E 20       01710         DB      '               All Rights Reserved. '
     20 20 20 20 20 20 20 20
     20 20 20 20 20 20 41 6C
     6C 20 52 69 67 68 74 73
     20 52 65 73 65 72 76 65
     64 2E 20 
F882 20       01711         DB      '               '
     20 20 20 20 20 20 20 20
     20 20 20 20 20 20 
              01712 ;       DB      'Licensed to Tandy Corporation.'
1948          01713         ORG     CORE$
              01714 ;
              01715 ;       get the system loader
              01716 ;
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00037 

'<System Loader and associated routines

MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00038 

'<System Loader and associated routines

1948          01719 *GET    LOADER:3
              01720 ;LOADER/ASM - LS-DOS 6.2
1948          01721 CORE$   DEFL    $
0100          01722         ORG     SVCTAB$
              01723 ;
              01724 ;       Supervisor Call table - Page 5
              01725 ;
0100 F21B     01726         DW      @IPL,@KEY,@DSP,@GET             ;0-3
     2806 4206 3806 
0108 4506     01727         DW      @PUT,@CTL,@PRT,@WHERE           ;4-7
     2306 3D06 7919 
0110 3506     01728         DW      @KBD,@KEYIN,@DSPLY,@LOGER       ;8-11
     8505 2D05 0305 
0118 0005     01729         DW      @LOGOT,@MSG,@PRINT,@VDCTL       ;12-15
     3005 2805 990B 
0120 8203     01730         DW      @PAUSE,@PARAM,@DATE,@TIME       ;16-19
     8719 2014 8D07 
0128 8906     01731         DW      @CHNIO,@ABORT,@EXIT,SVCERR      ;20-23
     081B 0B1B F41A 
0130 7E19     01732         DW      @CMNDI,@CMNDR,@ERROR,@DEBUG     ;24-27
     7B19 0F1B A019 
0138 F51C     01733         DW      @CKTSK,@ADTSK,@RMTSK,@RPTSK     ;28-31
     DA1C D71C EB1C 
0140 D01C     01734         DW      @KLTSK,@CKDRV,@DODIR,@RAMDIR    ;32-35
     9319 AF19 AC19 
0148 F41A     01735         DW      SVCERR,SVCERR,SVCERR,SVCERR     ;36-39
     F41A F41A F41A 
0150 B519     01736         DW      @DCSTAT,@SLCT,@DCINIT,@DCRES    ;40-43
     BC19 C019 C419 
0158 C819     01737         DW      @RSTOR,@STEPI,@SEEK,@RSLCT      ;44-47
     CC19 D019 D419 
0160 D819     01738         DW      @RDHDR,@RDSEC,@VRSEC,@RDTRK     ;48-51
     F419 DC19 E019 
0168 E419     01739         DW      @HDFMT,@WRSEC,@WRSSC,@WRTRK     ;52-55
     E819 EC19 F019 
0170 9619     01740         DW      @RENAME,@REMOVE,@INIT,@OPEN     ;56-59
     A619 8D19 8A19 
0178 9919     01741         DW      @CLOSE,@BKSP,@CKEOF,@LOC        ;60-63
     AD14 8F15 DA14 
0180 0515     01742         DW      @LOF,@PEOF,@POSN,@READ          ;64-67
     C914 5B14 1315 
0188 C214     01743         DW      @REW,@RREAD,@RWRIT,@SEEKSC      ;68-71
     9A14 AD13 A013 
0190 5714     01744         DW      @SKIP,@VER,@WEOF,@WRITE         ;72-75
     6015 3014 3115 
0198 381B     01745         DW      @LOAD,@RUN,@FSPEC,@FEXT         ;76-79
     1D1B 8119 8419 
01A0 9C19     01746         DW      @FNAME,@GTDCT,@GTDCB,@GTMOD     ;80-83
     1E1A 9019 B219 
01A8 F41A     01747         DW      SVCERR,@RDSSC,@GATRD,@DIRRD     ;84-87
     D818 7418 BB18 
01B0 0318     01748         DW      @DIRWR,@GATWR,@MUL8,@MUL16      ;88-91
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00039 

'<System Loader and associated routines

     7518 0A19 C906 
01B8 F41A     01749         DW      SVCERR,@DIV8,@DIV16,@HEXD       ;92-95
     2719 E306 F806 
01C0 E103     01750         DW      @DECHEX,@HEXDEC,@HEX8,@HEX16    ;96-99
     F606 C207 BD07 
01C8 4819     01751         DW      @HIGH$,@FLAGS,@BANK,@BREAK      ;100-103
     6A19 7708 6F19 
01D0 9203     01752         DW      @SOUND,@CLS,@CKBRKC,@VDPRT      ;104-107
     4505 5305 3509 
01D8 F41A     01753         DW      SVCERR,SVCERR,SVCERR,SVCERR     ;108-111
     F41A F41A F41A 
01E0 F41A     01754         DW      SVCERR,SVCERR,SVCERR,SVCERR     ;112-115
     F41A F41A F41A 
01E8 F41A     01755         DW      SVCERR,SVCERR,SVCERR,SVCERR     ;116-119
     F41A F41A F41A 
01F0 F41A     01756         DW      SVCERR,SVCERR,SVCERR,SVCERR     ;120-123
     F41A F41A F41A 
01F8 F41A     01757         DW      SVCERR,SVCERR,SVCERR,SVCERR     ;124-127
     F41A F41A F41A 
1948          01758         ORG     CORE$
              01759 ;
              01760 ;       Routine to set or retrieve HIGH$/LOW$
              01761 ;
1948 7C       01762 @HIGH$  LD      A,H             ;Test if put or get
1949 B5       01763         OR      L
194A 2812     01764         JR      Z,GETHILO       ;Go if get
194C 3A6C00   01765         LD      A,(CFLAG$)      ;Is HIGH$ changeable?
194F 0F       01766         RRCA
1950 3E2B     01767         LD      A,43            ;Init SVC parm error
1952 D8       01768         RET     C               ;Back with NZ
1953 04       01769         INC     B               ;Test for HIGH$/LOW$
1954 05       01770         DEC     B
1955 200E     01771         JR      NZ,PUTLO        ;Go if LOW$
1957 220E04   01772         LD      (HIGH$),HL      ;Set new HIGH$
195A 2A0E04   01773 GETHI   LD      HL,(HIGH$)      ;P/u the value &
195D C9       01774         RET                     ;  ret with Z-flag
195E 04       01775 GETHILO INC     B               ;Test for HIGH$/LOW$
195F 05       01776         DEC     B
1960 28F8     01777         JR      Z,GETHI
1962 2A1E00   01778         LD      HL,(LOW$)       ;P/u LOW$
1965 221E00   01779 PUTLO   LD      (LOW$),HL       ;Get LOW$
1968 AF       01780         XOR     A               ;Set Z-flag
1969 C9       01781         RET
              01782 ;
196A FD216A00 01783 @FLAGS  LD      IY,FLGTAB$
196E C9       01784         RET
              01785 ;
196F E5       01786 @BREAK  PUSH    HL              ;Save user vector
1970 2A881C   01787         LD      HL,(BRKVEC$)    ;P/u current vector
1973 E3       01788         EX      (SP),HL         ;Save current & get user
1974 22881C   01789         LD      (BRKVEC$),HL    ;Stuff new vector
1977 E1       01790         POP     HL              ;Recover old vector
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00040 

'<System Loader and associated routines

1978 C9       01791         RET
              01792 ;
1979 E1       01793 @WHERE  POP     HL
197A E9       01794         JP      (HL)
              01795 ;
              01796 ;       Code for these SVCs is in system overlays
              01797 ;
197B 3EA3     01798 @CMNDR  LD      A,0A3H          ;Interpret command & RET
197D EF       01799         RST     40
197E 3EB3     01800 @CMNDI  LD      A,0B3H          ;Interpret a command
1980 EF       01801         RST     40
1981 3EC3     01802 @FSPEC  LD      A,0C3H          ;Parse a filespec
1983 EF       01803         RST     40
1984 3ED3     01804 @FEXT   LD      A,0D3H          ;Optional default EXT
1986 EF       01805         RST     40
1987 3EE3     01806 @PARAM  LD      A,0E3H          ;Parameter scanner
1989 EF       01807         RST     40
198A 3E94     01808 @OPEN   LD      A,94H           ;Open a file
198C EF       01809         RST     40
198D 3EA4     01810 @INIT   LD      A,0A4H          ;Initialize a file
198F EF       01811         RST     40
1990 3EB4     01812 @GTDCB  LD      A,0B4H          ;Get a DCB vector
1992 EF       01813         RST     40
1993 3EC4     01814 @CKDRV  LD      A,0C4H          ;Drive available?
1995 EF       01815         RST     40
1996 3EF4     01816 @RENAME LD      A,0F4H          ;Rename a file
1998 EF       01817         RST     40
1999 3E95     01818 @CLOSE  LD      A,95H           ;Close a file
199B EF       01819         RST     40
199C 3EA5     01820 @FNAME  LD      A,0A5H          ;Recover filespec
199E EF       01821         RST     40
199F C9       01822 @DBGHK  RET                     ;Init DEBUG off (NOP=on)
19A0 F5       01823 @DEBUG  PUSH    AF
19A1 3E97     01824         LD      A,97H           ;Enter system Debugger
19A3 EF       01825         RST     40
19A4 0315     01826 EXTDBG$ DW      ORARET@         ;Hook for extended DEBUG
19A6 3E9C     01827 @REMOVE LD      A,9CH           ;Remove a file/device
19A8 EF       01828         RST     40
19A9 3ECD     01829 @DOKEY  LD      A,0CDH          ;DO execution
19AB EF       01830         RST     40
19AC 3E9E     01831 @RAMDIR LD      A,09EH          ;Directory data
19AE EF       01832         RST     40
19AF 3EAE     01833 @DODIR  LD      A,0AEH          ;Directory data
19B1 EF       01834         RST     40
19B2 3EBE     01835 @GTMOD  LD      A,0BEH          ;Get module address
19B4 EF       01836         RST     40
              01837 ;
              01838 ;       These SVCs handle the disk primitive requests
              01839 ;
19B5 AF       01840 @DCSTAT XOR     A               ;FDC status
19B6 183E     01841         JR      IOFUNC
19B8 3A2300   01842 TAPDRV  LD      A,(LDRV$)       ;P/u drive #
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00041 

'<System Loader and associated routines

19BB 4F       01843         LD      C,A
19BC 3E01     01844 @SLCT   LD      A,1             ;Select drive
19BE 1836     01845         JR      IOFUNC
19C0 3E02     01846 @DCINIT LD      A,2             ;FDC init
19C2 1832     01847         JR      IOFUNC
19C4 3E03     01848 @DCRES  LD      A,3             ;FDC reset
19C6 182E     01849         JR      IOFUNC
19C8 3E04     01850 @RSTOR  LD      A,4             ;Restore to cyl 0
19CA 182A     01851         JR      IOFUNC
19CC 3E05     01852 @STEPI  LD      A,5             ;Step in 1 cyl
19CE 1826     01853         JR      IOFUNC
19D0 3E06     01854 @SEEK   LD      A,6             ;Seek a track/sector
19D2 1822     01855         JR      IOFUNC
19D4 3E07     01856 @RSLCT  LD      A,7             ;Re-select drive
19D6 181E     01857         JR      IOFUNC
19D8 3E08     01858 @RDHDR  LD      A,8
19DA 181A     01859         JR      IOFUNC
19DC 3E0A     01860 @VRSEC  LD      A,10            ;Verify a sector
19DE 1816     01861         JR      IOFUNC
19E0 3E0B     01862 @RDTRK  LD      A,11
19E2 1812     01863         JR      IOFUNC
19E4 3E0C     01864 @HDFMT  LD      A,12
19E6 180E     01865         JR      IOFUNC
19E8 3E0D     01866 @WRSEC  LD      A,13            ;Write standard sector
19EA 180A     01867         JR      IOFUNC
19EC 3E0E     01868 @WRSSC  LD      A,14            ;Write a system sector
19EE 1806     01869         JR      IOFUNC
19F0 3E0F     01870 @WRTRK  LD      A,15            ;Write a track
19F2 1802     01871         JR      IOFUNC
19F4 3E09     01872 @RDSEC  LD      A,9             ;Read a sector
              01873 ;
19F6 C5       01874 IOFUNC  PUSH    BC              ;Save reg pair
19F7 47       01875         LD      B,A             ;Xfer the function code
              01876 ;
              01877 ;       Bring up bank 0
              01878 ;
19F8 C5       01879         PUSH    BC
19F9 AF       01880         XOR     A
19FA 47       01881         LD      B,A             ;Set bank function 0,
19FB 4F       01882         LD      C,A             ;  bank number 0
19FC CD7708   01883         CALL    @BANK           ;Bring up bank
19FF F1       01884         POP     AF              ;Perform EX (SP),BC
1A00 C5       01885         PUSH    BC
1A01 F5       01886         PUSH    AF
1A02 C1       01887         POP     BC
              01888 ;
              01889 ;       Continue disk I/O setup
              01890 ;
1A03 79       01891         LD      A,C             ;Xfer the drive code
1A04 322300   01892         LD      (LDRV$),A
1A07 FDE5     01893         PUSH    IY
1A09 CD1E1A   01894         CALL    @GTDCT          ;Get DCT address in IY
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00042 

'<System Loader and associated routines

1A0C 3E20     01895         LD      A,20H           ;Set illegal drive #
1A0E B7       01896         OR      A               ;  if drive disabled
1A0F CD1C1A   01897         CALL    GODOIO
1A12 FDE1     01898         POP     IY
              01899 ;
              01900 ;       Bring back the old bank
              01901 ;
1A14 C1       01902         POP     BC
1A15 F5       01903         PUSH    AF              ;Save disk I/O retcod
1A16 3E66     01904         LD      A,102           ;Set for @BANK
1A18 EF       01905         RST     40              ;No need to ck for error
              01906                                 ;  from @BANK
1A19 F1       01907         POP     AF
1A1A C1       01908         POP     BC
1A1B C9       01909         RET
              01910 ;
1A1C FDE9     01911 GODOIO  JP      (IY)
              01912 ;
1A1E E5       01913 @GTDCT  PUSH    HL              ;Get i/o routine addr
1A1F CD341A   01914         CALL    DCTFLD@         ;  into IY
1A22 E3       01915         EX      (SP),HL
1A23 FDE1     01916         POP     IY
1A25 C9       01917         RET
              01918 ;
              01919 ;       Entry to get DCT+8 of FCB (IX) drive spec
              01920 ;
1A26 DD4E06   01921 D@FBYT8 LD      C,(IX+6)        ;P/u drive
              01922 ;
              01923 ;       Entry to get DCT+8 of Reg C drive spec
              01924 ;
              01925 DCTBYT8@
1A29 3E08     01926         LD      A,8
              01927 ;
              01928 ;       Entry to get byte (Reg A) from DCT of Reg C drive
              01929 ;        C => logical drive specification
              01930 ;        A => relative byte requested from DCT
              01931 ;        A <= data at position requested
              01932 ;
1A2B E5       01933 @DCTBYT PUSH    HL              ;Save the register pair
1A2C 67       01934         LD      H,A             ;Xfer relative position
1A2D CD341A   01935         CALL    DCTFLD@         ;Get HL pointing to
1A30 6F       01936         LD      L,A             ;  DCT position
1A31 7E       01937         LD      A,(HL)          ;Get the byte
1A32 E1       01938         POP     HL
1A33 C9       01939         RET
              01940 ;
              01941 ;       Entry to get HL pointing to DCT byte Reg C, Reg A
              01942 ;        C => logical drive number
              01943 ;        A => relative byte in DCT requested
              01944 ;       HL <= start of requested DCT for the drive
              01945 ;        A <= low order pointer to relative byte request
              01946 ;
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00043 

'<System Loader and associated routines

1A34 79       01947 DCTFLD@ LD      A,C             ;Get drive spec &
1A35 E607     01948         AND     7               ;  strip excess data
1A37 87       01949         ADD     A,A             ;Times 2
1A38 6F       01950         LD      L,A             ;  & saved
1A39 87       01951         ADD     A,A             ;Times 4
1A3A 87       01952         ADD     A,A             ;Times 8
1A3B 85       01953         ADD     A,L             ;Times 10
1A3C C670     01954         ADD     A,70H           ;Add DCT offset from 0
1A3E 6F       01955         LD      L,A             ;Point L to DCT low order
1A3F 84       01956         ADD     A,H             ;Add in rel pos desired
1A40 2604     01957         LD      H,DCT$<-8       ;Point H to DCT hi-order
1A42 C9       01958         RET
              01959 ;
              01960 ;       Process supervisory calls <0-127>
              01961 ;
1A43 FE1A     01962 SVCUSER CP      26              ;Check for @ERROR
1A45 2808     01963         JR      Z,ERRSVC        ;Skip next if so
1A47 320D00   01964         LD      (LSVC$),A       ;Store SVC request
1A4A E3       01965         EX      (SP),HL         ;P/u RET address
1A4B 220B00   01966         LD      (SVCRET$),HL    ;  and save it
1A4E E3       01967         EX      (SP),HL         ;Restore RET address
1A4F E5       01968 ERRSVC  PUSH    HL              ;Save HL
1A50 07       01969         RLCA                    ;Multiply by two
1A51 2601     01970         LD      H,SVCTAB$<-8    ;Base of table
1A53 6F       01971         LD      L,A             ;Set up the low order
1A54 7E       01972         LD      A,(HL)          ;P/u table entry
1A55 2C       01973         INC     L
1A56 66       01974         LD      H,(HL)
1A57 6F       01975         LD      L,A
1A58 E3       01976         EX      (SP),HL         ;P/u HL & stuff vector
1A59 79       01977         LD      A,C             ;Xfer for PUT type ops
1A5A C9       01978         RET
              01979 ;
              01980 ;       RST 28 vector - System & user SVCs
              01981 ;
1A5B B7       01982 RST28   OR      A               ;Test if bit 7 set
1A5C F2431A   01983         JP      P,SVCUSER       ;Jump on user SVC attempt
1A5F E3       01984         EX      (SP),HL         ;Discard return addr &
1A60 F5       01985         PUSH    AF              ;  save HL, AF
1A61 219F19   01986         LD      HL,@DBGHK       ;Set up DEBUG linkage
1A64 7E       01987         LD      A,(HL)
1A65 32791A   01988         LD      (SET@EXEC),A
1A68 36C9     01989         LD      (HL),0C9H
1A6A F1       01990         POP     AF              ;Restore AF, HL
1A6B E1       01991         POP     HL
1A6C CD7F1A   01992 HKRES$  CALL    CKMOD@          ;Get overlay if needed
1A6F 3E00     01993         LD      A,0             ;P/u new overlay #
1A70          01994 OVRLYOLD        EQU     $-1
1A71 326900   01995         LD      (OVRLY$),A      ;  & update current
1A74 CD0000   01996 TRANSFR CALL    0               ;Traadr of SYSx
1A77 F5       01997         PUSH    AF
1A78 3E00     01998         LD      A,0             ;Set to C9 if EXEC only
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00044 

'<System Loader and associated routines

1A79          01999 SET@EXEC        EQU     $-1
1A7A 329F19   02000         LD      (@DBGHK),A
1A7D F1       02001         POP     AF
1A7E C9       02002         RET
              02003 ;
              02004 ;       DOS command overlay request
              02005 ;
1A7F E5       02006 CKMOD@  PUSH    HL
1A80 67       02007         LD      H,A             ;Save command value
1A81 78       02008         LD      A,B
1A82 32D21A   02009         LD      (EXOVR2+1),A    ;Set overlay #
1A85 7C       02010         LD      A,H
1A86 F601     02011         OR      1               ;Set for SYS6 & SYS7
1A88 FE89     02012         CP      89H             ;Is it either?
1A8A 7C       02013         LD      A,H             ;Get back the correct #
1A8B 2813     02014         JR      Z,EXOVR         ;Sys6/7 req? Use ISAM!
1A8D FE8A     02015         CP      8AH             ;Sys8 also ISAM
1A8F 280F     02016         JR      Z,EXOVR
1A91 3A6900   02017         LD      A,(OVRLY$)      ;P/u current overlay
1A94 AC       02018         XOR     H               ;Ck if it's the one
1A95 E60F     02019         AND     0FH             ;  we need to execute
1A97 7C       02020         LD      A,H
1A98 32701A   02021         LD      (OVRLYOLD),A    ;Update current tempy
1A9B 21001E   02022         LD      HL,OVERLAY      ;Init to SYSx entry
1A9E 283A     02023         JR      Z,EXOVR3        ;Go exec if resident
              02024 ;
              02025 ;       Execute a system overlay
              02026 ;
1AA0 D5       02027 EXOVR   PUSH    DE
1AA1 C5       02028         PUSH    BC
1AA2 E60F     02029         AND     0FH             ;Get right nybble
1AA4 CB5F     02030         BIT     3,A             ;Check for SYS0-7
1AA6 2802     02031         JR      Z,EXOVR1        ;  w/o changing carry
1AA8 C618     02032         ADD     A,18H           ;Adjust for sys8-15
1AAA 329300   02033 EXOVR1  LD      (SFCB$+7),A
1AAD 47       02034         LD      B,A             ;Set DEC for directory
1AAE 3E20     02035         LD      A,20H           ;Set bit 5 of FCB+1
1AB0 328D00   02036         LD      (SFCB$+1),A
1AB3 ED62     02037         SBC     HL,HL           ;Carry is clear here
1AB5 229600   02038         LD      (SFCB$+10),HL   ;Zero NRN
1AB8 4C       02039         LD      C,H             ;Init for drive 0
1AB9 CDBB18   02040         CALL    @DIRRD          ;Read dir entry
1ABC 201A     02041         JR      NZ,EXERR        ;Go if error
1ABE 7E       02042         LD      A,(HL)          ;Was overlay purged?
1ABF E650     02043         AND     50H             ;  or is it non-system?
1AC1 EE50     02044         XOR     50H
1AC3 3E07     02045         LD      A,7             ;Init "deleted error
1AC5 2011     02046         JR      NZ,EXERR
1AC7 7D       02047         LD      A,L
1AC8 C616     02048         ADD     A,22            ;Point to 1st extent
1ACA 6F       02049         LD      L,A
1ACB 119A00   02050         LD      DE,SFCB$+14     ;Extent field in FCB
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00045 

'<System Loader and associated routines

1ACE CDE11A   02051         CALL    PAT1            ;Stuff 1st two extents
1AD1 0600     02052 EXOVR2  LD      B,0             ;P/u ISAM # or zero
1AD3 1E8C     02053         LD      E,SFCB$&0FFH
1AD5 CD561B   02054         CALL    LOADER          ;Read system overlay
1AD8 C1       02055 EXERR   POP     BC
1AD9 D1       02056         POP     DE
1ADA 22751A   02057 EXOVR3  LD      (TRANSFR+1),HL  ;Stuff overlay entry pt
1ADD E1       02058         POP     HL
1ADE C8       02059         RET     Z
1ADF 1816     02060         JR      SYSERR          ;Go if I/O error on read
              02061 ;
              02062 ;       Routine to calculate 1st two extents of SYS file
              02063 ;
1AE1 CDEC1A   02064 PAT1    CALL    PAT1A           ;Move first extent
1AE4 E61F     02065         AND     1FH             ;Compute # of granules
1AE6 3C       02066         INC     A
1AE7 12       02067         LD      (DE),A          ;And store in FCB
1AE8 13       02068         INC     DE
1AE9 AF       02069         XOR     A
1AEA 12       02070         LD      (DE),A
1AEB 13       02071         INC     DE
1AEC CDEF1A   02072 PAT1A   CALL    PAT1B           ;Move second extent
1AEF 7E       02073 PAT1B   LD      A,(HL)
1AF0 12       02074         LD      (DE),A
1AF1 23       02075         INC     HL
1AF2 13       02076         INC     DE
1AF3 C9       02077         RET
              02078 ;
              02079 ;       System error display routine
              02080 ;       The NOP is provided so an intercept routine vector
              02081 ;        may be patched in during program development
              02082 ;
1AF4 3E2B     02083 SVCERR  LD      A,43            ;SVC error
1AF6 00       02084         NOP
1AF7 E63F     02085 SYSERR  AND     3FH             ;Strip excess bits
1AF9 21191B   02086         LD      HL,ERRNUM       ;Pack error number
1AFC CDC207   02087         CALL    @HEX8           ;  into message
1AFF 21131B   02088         LD      HL,SYSERR$
1B02 CD0005   02089         CALL    @LOGOT          ;Log the error & ABORT
1B05 318003   02090         LD      SP,STACK$       ;reset stack
1B08 21FFFF   02091 @ABORT  LD      HL,-1
1B0B 3E93     02092 @EXIT   LD      A,93H           ;Exit to DOS
1B0D EF       02093         RST     40
              02094 ;
1B0E E1       02095 POPERR  POP     HL              ;Pop extended error
1B0F F5       02096 @ERROR  PUSH    AF              ;Save the error code
1B10 3E96     02097         LD      A,96H           ;Display the error number
1B12 EF       02098         RST     40
              02099 ;
1B13 45       02100 SYSERR$ DM      'Error '
     72 72 6F 72 20 
1B19 78       02101 ERRNUM  DM      'xxH',CR
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00046 

'<System Loader and associated routines

     78 48 0D 
              02102 ;
              02103 ;       Routine to RUN a program
              02104 ;
1B1D E5       02105 @RUN    PUSH    HL              ;Save register pair
1B1E 217C00   02106         LD      HL,SFLAG$
1B21 CBD6     02107         SET     2,(HL)          ;Turn on RUN flag bit
1B23 CD381B   02108         CALL    @LOAD           ;Load the program module
1B26 E3       02109         EX      (SP),HL         ;Put traadr on the stack
              02110 ;
              02111 ;       Note: The error code is set to NOT abort. Errors
              02112 ;        will be passed back to the calling module after
              02113 ;        @ERROR. Note that HL will contain the error #.
              02114 ;
1B27 20E5     02115         JR      NZ,POPERR
              02116 ;
              02117 ;       Place the INBUF$ pointer in register pair BC
              02118 ;
1B29 012004   02119         LD      BC,INBUF$       ;Reflect buffer pointer
              02120 ;
              02121 ;       Get TRAADR then test if we need to go to DEBUG
              02122 ;
1B2C 3A7C00   02123         LD      A,(SFLAG$)
1B2F CB4F     02124         BIT     1,A             ;Go to the program if
1B31 C0       02125         RET     NZ              ;  its EXEC only access
1B32 CB7F     02126         BIT     7,A             ;  else test if DEBUG
1B34 C23000   02127         JP      NZ,@RST30       ;  is on & go to it
1B37 C9       02128         RET                     ;  else go to program
              02129 ;
              02130 ;       This routine LOADs a Load Module Format file
              02131 ;
1B38 0600     02132 @LOAD   LD      B,0             ;LRL=256
1B3A 217C00   02133         LD      HL,SFLAG$
1B3D CBC6     02134         SET     0,(HL)          ;Don't set "file open"
1B3F 21001D   02135         LD      HL,SBUFF$       ;Set buffer to system
1B42 CD8A19   02136         CALL    @OPEN           ;Open the file
1B45 D5       02137         PUSH    DE              ;Save FCB pointer
1B46 CC561B   02138         CALL    Z,LOADER        ;Load if no OPEN error
1B49 D1       02139         POP     DE              ;Restore FCB pointer
1B4A C8       02140         RET     Z               ;Back if no error
1B4B 6F       02141         LD      L,A             ;Xfer the error code
1B4C 2600     02142         LD      H,0
1B4E F6C0     02143         OR      0C0H            ;Set RETurn & abbrev
1B50 FED8     02144         CP      0D8H            ;Change "file not in dir"
1B52 C0       02145         RET     NZ              ;  to "program not found"
1B53 C607     02146         ADD     A,7
1B55 C9       02147         RET
              02148 ;
              02149 ;       System command file loader
              02150 ;
1B56 78       02151 LOADER  LD      A,B             ;Set overlay # (0 on non
1B57 32B31B   02152         LD      (LDR14+1),A     ;  SYStem file)
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00047 

'<System Loader and associated routines

1B5A D5       02153         PUSH    DE              ;Save IX & xfer FCB to IX
1B5B DDE3     02154         EX      (SP),IX
1B5D 11FF1D   02155         LD      DE,SBUFF$+255   ;Init to end of buffer
1B60 CD6F1B   02156         CALL    LDR01           ;Do the load
1B63 DDE1     02157         POP     IX              ;Recover IX
1B65 C9       02158         RET
              02159 ;
              02160 ;       Routine to ignore the LMF record
              02161 ;
1B66 CDD61B   02162 LDR05   CALL    LDR15           ;Get length of "comment"
1B69 47       02163         LD      B,A
1B6A CDD61B   02164 LDR06   CALL    LDR15           ;Read & ignore that many
1B6D 10FB     02165         DJNZ    LDR06           ;  bytes then fall thru
              02166 ;
              02167 ;       Routine to parse LMF record types
              02168 ;
1B6F CDD61B   02169 LDR01   CALL    LDR15           ;Get record type
1B72 FE01     02170 LDR02   CP      1               ;Start of block?
1B74 281F     02171         JR      Z,LDR08
1B76 FE02     02172         CP      2               ;Start of TRAADR?
1B78 2814     02173 LDR03   JR      Z,LDR07
1B7A FE04     02174         CP      4               ;End of LIB member?
1B7C 282A     02175         JR      Z,LDR12
1B7E FE08     02176         CP      8               ;Begin ISAM table entry?
1B80 2828     02177         JR      Z,LDR13
1B82 FE0A     02178         CP      10              ;End of ISAM map?
1B84 2804     02179         JR      Z,LDR04
1B86 FE20     02180         CP      20H             ;Ignore all other control
1B88 38DC     02181         JR      C,LDR05
1B8A 3E22     02182 LDR04   LD      A,22H           ;Load file format err
1B8C B7       02183         OR      A
1B8D C9       02184         RET
              02185 ;
              02186 ;       Grab transfer address
              02187 ;
1B8E CDD61B   02188 LDR07   CALL    LDR15           ;Bypass 2nd X'02'
1B91 CDE81B   02189         CALL    GETADR          ;P/u transfer address
1B94 C9       02190         RET                     ;Ret Z or NZ
              02191 ;
              02192 ;       Grab load block
              02193 ;
1B95 CDD61B   02194 LDR08   CALL    LDR15           ;P/u block len
1B98 47       02195         LD      B,A
1B99 CDE81B   02196         CALL    GETADR          ;P/u load address
1B9C C0       02197         RET     NZ
1B9D 05       02198         DEC     B               ;Adj length for adr
1B9E 05       02199         DEC     B
1B9F CDD61B   02200 LDR09   CALL    LDR15           ;P/u block byte
1BA2 77       02201         LD      (HL),A
1BA3 23       02202         INC     HL
1BA4 10F9     02203         DJNZ    LDR09           ;Loop until block end
1BA6 18C7     02204         JR      LDR01
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00048 

'<System Loader and associated routines

              02205 ;
1BA8 E1       02206 LDR12   POP     HL
1BA9 C9       02207         RET
              02208 ;
              02209 ;       Routine to check ISAM table match
              02210 ;
1BAA CDD61B   02211 LDR13   CALL    LDR15           ;Get record length
1BAD 47       02212         LD      B,A
1BAE CDD61B   02213         CALL    LDR15           ;Get ISAM number
1BB1 05       02214         DEC     B               ;  & decrement counter
1BB2 FE00     02215 LDR14   CP      0               ;Either ISAM# or 0
1BB4 20B4     02216         JR      NZ,LDR06        ;Go if not a match
1BB6 CDE81B   02217         CALL    GETADR          ;  else get the TRAADR
1BB9 E5       02218         PUSH    HL              ;  & save it
1BBA CCE81B   02219         CALL    Z,GETADR        ;Get the NRN for member
1BBD 2027     02220         JR      NZ,LODERR
1BBF CDD61B   02221         CALL    LDR15           ;Get the sector offset
1BC2 5F       02222         LD      E,A             ;Update pointer offset
1BC3 C5       02223         PUSH    BC
1BC4 44       02224         LD      B,H             ;Xfer NRN position needed
1BC5 4D       02225         LD      C,L
1BC6 D5       02226         PUSH    DE              ;Save buffer ptr offset
1BC7 DDE5     02227         PUSH    IX
1BC9 D1       02228         POP     DE              ;P/u FCB into DE
1BCA CD5B14   02229         CALL    @POSN           ;Position to ISAM rec
1BCD D1       02230         POP     DE              ;Rcvr buffer ptr offset
1BCE C1       02231         POP     BC
1BCF 2015     02232         JR      NZ,LODERR
1BD1 CDDB1B   02233         CALL    LDR17           ;Read the sector
1BD4 189C     02234         JR      LDR02           ;Now go read the member
              02235 ;
              02236 ;       Routine to get the next file byte
              02237 ;
1BD6 1C       02238 LDR15   INC     E               ;Bump buf pointer
1BD7 2802     02239         JR      Z,LDR17         ;Read sector if needed
1BD9 1A       02240 LDR16   LD      A,(DE)          ;P/U byte from buffer
1BDA C9       02241         RET
1BDB E5       02242 LDR17   PUSH    HL              ;Save regs
1BDC D5       02243         PUSH    DE
1BDD C5       02244         PUSH    BC
1BDE CD7513   02245         CALL    NXTSECT         ;Read next record
1BE1 C1       02246         POP     BC              ;Restore regs
1BE2 D1       02247         POP     DE
1BE3 E1       02248         POP     HL
1BE4 28F3     02249         JR      Z,LDR16         ;Bypass if no error
1BE6 C1       02250 LODERR  POP     BC              ;Pop return address
1BE7 C9       02251         RET
              02252 ;
              02253 ;       Routine to get an address field
              02254 ;
1BE8 CDD61B   02255 GETADR  CALL    LDR15           ;Get low order byte
1BEB 6F       02256         LD      L,A
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00049 

'<System Loader and associated routines

1BEC CDD61B   02257         CALL    LDR15           ;Get hi order byte
1BEF 67       02258         LD      H,A
1BF0 BF       02259         CP      A
1BF1 C9       02260         RET
              02261 ;
              02262 ;       BOOT code brings back the ROM
              02263 ;
4300          02264 MOD3BUF EQU     4300H
1BF2 21FB03   02265 @IPL    LD      HL,BOOTCOD      ;Code to toggle in ROM
1BF5 110043   02266         LD      DE,MOD3BUF      ;Buffer used by ROM
1BF8 D5       02267         PUSH    DE              ;This is return address
1BF9 010500   02268         LD      BC,BOOTLEN
1BFC EDB0     02269         LDIR                    ;Transfer boot code and
1BFE C9       02270         RET                     ;  jump to it
              02271 ;
              02272 ;       End of loader module
              02273 ;
MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00050 

'<System front end & task processor

MISOSYS EDAS-4.3 04/11/99 20:43:48 SYSRES - LS-DOS 6.2          Page 00051 

'<System front end & task processor

1BFF          02276 *GET    TASKER:3
              02277 ;TASKER/ASM - LS-DOS 6.2
              02278 ;
              02279 ;       Interrupt task table, IM 1
              02280 ;
1BFF          02281 CORE$   DEFL    $
004E          02282         ORG     TCB$
004E E91C     02283         DW      NOTASK,NOTASK,NOTASK,NOTASK
     E91C E91C E91C 
0056 E91C     02284         DW      NOTASK,NOTASK,NOTASK,NOTASK
     E91C E91C E91C 
005E E91C     02285         DW      NOTASK,NOTASK,TYPTSK$,NOTASK
     E91C 260B E91C 
1BFF          02286         ORG     CORE$
              02287 ;
              02288 ;       Model IV task processor
              02289 ;
              02290 RST38@
1BFF E3       02291         EX      (SP),HL
1C00 22AF07   02292