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/ Apple II Magazines (PO) / Nibble Volume 10, No. 05 (1989-05)(MicroSPARC)(Side A)[a].zip / Nibble Volume 10, No. 05 (1989-05)(MicroSPARC)(Side A)[a].po / RESET.S.txt < prev next >

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Text File | 1996-12-24 | 15KB | 330 lines

************************** * RESET.OBJ SOURCE CODE * * BY KENN SCRIBNER * * COPYRIGHT (C) 1989 * * MICROSPARC, INC. * * CONCORD, MA 01742 * ************************** * * * ORCA/M 4.1 Assembler * ORG $6EC7 KEEP RESET RESET START ;............................................................... ; ; Program EQUates. ;............................................................... CSWL EQU $36 ;monitor character output hook KSWL EQU $38 ;monitor character input hook VBL1 EQU $3C ;temporary storage location VBL2 EQU $3D ;temporary storage location VBL3 EQU $3E ;temporary storage location VBL4 EQU $3F ;temporary storage location A1L EQU $3C ;source starting address for MOVE A2L EQU $3E ;source ending address for MOVE A4L EQU $42 ;destination address for MOVE LINNUM EQU $50 ;ASoft line number in progress CURLIN EQU $75 ;ASoft line number in progress VARPNT EQU $83 ;pointer to ASoft variable data TXTPTR EQU $B8 ;current ASoft token's address ERRPOS EQU $DC ;temporary storage for TXTPTR INBUFR EQU $200 ;DOS command input buffer RSTVCTL EQU $3F2 ;reset vector low byte RSTVCTH EQU $3F3 ;reset vector high byte RSTVCTV EQU $3F4 ;reset vector power-up validation byte ERROR EQU $D412 ;ASoft error handler, errnum in xreg STKINI EQU $D683 ;restore ASoft's stack pointer STXTPT EQU $D697 ;reset TXTPTR to beginning of program NEWSTT EQU $D7D2 ;execute ASoft program from TXTPTR GETLIN EQU $D941 ;find line in LINNUM in memory PTRGET EQU $DFE3 ;find/create simple variable in memory GIVAYF EQU $E2F2 ;convert integer in A,Y to floating pt. GETADR EQU $E752 ;convert floating pt. number to integer MOVFM EQU $EAF9 ;unpack variable data and move to FAC MOVMF EQU $EB2B ;pack FAC data and move to variable SETHMEM1 EQU $F28E ;calculate and set HIMEM from LINNUM MOVE EQU $FE2C ;monitor memory move routine ;............................................................... ; ; ProDOS and BASIC.SYSTEM EQUates. ;............................................................... DOSCMD EQU $BE03 ;execute DOS command stored at $200 ERROUT EQU $BE09 ;BASIC.SYSTEM error handler VECTOUT EQU $BE30 ;BASIC.SYSTEM output link VECTIN EQU $BE32 ;BASIC.SYSTEM input link GETBUFR EQU $BEF5 ;reserve x pages above HIMEM, x in areg KVERSION EQU $BFFF ;ProDOS Kernel Version ;............................................................... ; ; DOS 3.3 EQUates. ;............................................................... CONNECT EQU $3EA ;DOS 3.3 I/O vector reconnection routine MAXFILES EQU $A258 ;DOS 3.3 MAXFILES command CLOSE EQU $A316 ;close all open DOS 3.3 files ;............................................................... ; ; Set up SV variable. ;............................................................... LDA #>SETUP ;variable data high byte STA VBL1 ;store it for subroutine LDA #<SETUP ;variable data low byte STA VBL2 ;store it LDA #>SVVBL ;variable name's location high byte STA VBL3 ;store it LDA #<SVVBL ;variable name's location low byte STA VBL4 ;store it JSR SETVBL ;set up the variable RTS ;done, let user initialize reset pgm ;............................................................... ; ; Set up RE variable. ;............................................................... SETUP LDA #$03 ;ASoft equivalent of LET RE = 1000 STA VBL1 LDA #$E8 ; ($03E8 = 1000 decimal) STA VBL2 LDA #>REVBL ;NOTE: this overwrites any previous STA VBL3 ; RE values! LDA #<REVBL STA VBL4 JSR SETVBL ;create/change variable LDA CSWL ;save I/O links so DOS may be recon- STA RST+1 ; nected after a reset. LDA CSWL+1 ;saving output links STA RST+5 LDA KSWL ;saving input links STA RST+9 LDA KSWL+1 STA RST+13 CHKDOS LDA KVERSION ;check which DOS we're running BMI DOS33 ;running DOS 3.3 PDOS LDA #$01 ;want 1 page (256 bytes) of reserved JSR GETBUFR ; space (moves HIMEM and protects us) BCC FIXPGM ;enough memory, okay to relocate pgm MEMERR LDX #$4D ;?OUT OF MEMORY error JMP ERROR ;not enough memory, flag user ;............................................................... ; ; This code "fixes" our program, since we don't know beforehand where ; BASIC.SYSTEM will want it moved. ;............................................................... FIXPGM STA FIX1+1 ;we need to correct any absolute STA FIX2+1 ; addresses to properly relocate code STA CLSLOOP+2 STA SETVECT+6 ;new reset vector's value (high byte) STA A4L+1 ;high byte of memory to relocate to LDA #$BE STA KILLVECT+6 ;point KV to $BE00 LDA #$00 ;low byte of memory to relocate to STA A4L STA KILLVECT+1 LDA #<RST ;beginning of program to be moved STA A1L LDA #>RST STA A1L+1 LDA #<END ;ending of program to be moved STA A2L LDA #>END STA A2L+1 LDY #$00 JSR MOVE ;move program ;............................................................... ; ; Set up KV and SV, kill vector and set vector for ProDOS version. ;............................................................... LDA FIX1+1 ;get high byte of set routine STA VBL1 ; (corrected for BASIC.SYSTEM move) LDA #<KILLVECT STA VBL2 LDA #>KVVBL ;find variable's name STA VBL3 LDA #<KVVBL STA VBL4 JSR SETVBL ;create/change KV LDA FIX1+1 ;get high byte of set routine STA VBL1 ; (corrected for BASIC.SYSTEM move) LDA #<SETVECT STA VBL2 LDA #>SVVBL ;find variable's name STA VBL3 LDA #<SVVBL STA VBL4 JSR SETVBL ;create/change SV BCC FIXVECT ;twiddle reset vector ;............................................................... ; ; DOS 3.3 version. We always know the reset program will load at ; $9600, so we won't need to fix it. ;............................................................... DOS33 LDA #$01 ;MAXFILES = 1 command JSR MAXFILES LDA #$00 ;set HIMEM to $9600 STA LINNUM LDA #$96 STA LINNUM+1 JSR SETHMEM1 ;calculate and set new HIMEM LDA #$00 ;low byte of memory to relocate to STA A4L LDA #$96 ;high byte of memory to relocate to STA A4L+1 LDA #<RST ;beginning of program to be moved STA A1L LDA #>RST STA A1L+1 LDA #<END ;ending of program to be moved STA A2L LDA #>END STA A2L+1 LDY #$00 JSR MOVE ;move program LDA #$96 ;get high byte of kill routine STA VBL1 LDA #<KILLVECT STA VBL2 LDA #>KVVBL ;find variable's name STA VBL3 LDA #<KVVBL STA VBL4 JSR SETVBL ;create/change KV LDA #$96 ;get high byte of set routine STA VBL1 LDA #<SETVECT STA VBL2 LDA #>SVVBL ;find variable's name STA VBL3 LDA #<SVVBL STA VBL4 JSR SETVBL ;create/change SV ;............................................................... ; ; Set up reset vector. ;............................................................... FIXVECT LDA #$00 ;low byte STA RSTVCTL FIX1 LDA #$96 ;(corrected) high byte STA RSTVCTH EOR #$A5 ;twiddle power-up byte STA RSTVCTV RTS ;done, ASoft reset enabled ;............................................................... ; ; Routine to create/find ASoft variables. ;............................................................... SETVBL LDA TXTPTR ;save present location in ASoft pgm STA ERRPOS LDA TXTPTR+1 STA ERRPOS+1 LDA VBL3 ;retrieve high byte of our variable STA TXTPTR+1 LDA VBL4 ;retrieve low byte of our variable STA TXTPTR JSR PTRGET ;find/create variable LDA VBL1 ;retrieve high byte's value LDY VBL2 ;retrieve low data byte's value JSR GIVAYF LDX VARPNT LDY VARPNT+1 JSR MOVMF LDA ERRPOS ;restore actual location of ASoft pgm STA TXTPTR LDA ERRPOS+1 STA TXTPTR+1 CLC ;clear carry to force branch on return RTS ;done! ;............................................................... ; ; Set and Kill variable names. ;............................................................... SVVBL DC H'53 56 00' ;"SV" KVVBL DC H'4B 56 00' ;"KV" ;............................................................... ; ; Reset routine. ;............................................................... RST LDA #$F0 ;reconnect default I/O links STA CSWL ;character output LDA #$FD ; (default 40 columns, COUT = $FDF0) STA CSWL+1 LDA #$1B ;character input STA KSWL ; (default keyboard) LDA #$FD STA KSWL+1 LDA KVERSION ;are we running ProDOS? BMI RSTDOS33 ;no, reset for DOS 3.3 LDA #$F0 ;set default BASIC.SYSTEM global vectors STA VECTOUT ; (character output --> $FDF0, or COUT) LDA #$FD STA VECTOUT+1 LDA #$1B ; (character input --> $FD1B, or KEYIN) STA VECTIN LDA #$FD STA VECTIN+1 CLSFILE LDX #$00 ;have BASIC.SYSTEM close all open files CLSLOOP LDA CLSCMD,X ;(we have BASIC.SYSTEM CLOSE files... BEQ CLSALL ;...rather than the ProDOS MLI 'cause... STA INBUFR,X ;...BASIC.SYSTEM does some other... INX ;...housekeeping the MLI doesn't) BNE CLSLOOP CLSCMD DC H'C3 CC CF D3 C5 8D 00' ;"CLOSE", with carriage return and $00 CLSALL JSR DOSCMD BCC READVBL LDA #$15 ;FILE(S) STILL OPEN error JMP ERROUT RSTDOS33 JSR CONNECT ;reconnect DOS 3.3 JSR CLOSE ;close all open files READVBL LDA #<REVBL ;retrieve line number from RE STA TXTPTR FIX2 LDA #$96 ;byte will be corrected for ProDOS call STA TXTPTR+1 JSR PTRGET ;find variable data JSR MOVFM ;move it to the FAC JSR GETADR ;convert it to integer (in LINNUM) LDA LINNUM+1 ;get high byte of line number STA CURLIN+1 ;store it for execution LDA LINNUM ;get low byte of line num STA CURLIN ;store it for execution JSR STKINI ;restore stack JSR STXTPT ;reset TXTPTR to beginning of program JSR GETLIN ;find our new line in memory JMP NEWSTT ;start execution at new line number ;............................................................... ; ; Restore variable name. ;............................................................... REVBL DC H'52 45 00' ;"RE" ;............................................................... ; ; Routine to re-enable the reset program. ;............................................................... SETVECT LDA #$00 ;point reset vector to $9600 STA RSTVCTL LDA #$96 ;will be modified for ProDOS version STA RSTVCTH EOR #$A5 STA RSTVCTV RTS ;............................................................... ; ; Routine to disable the reset program. ;............................................................... KILLVECT LDA #$BF ;restore reset vector to default values STA RSTVCTL ;($9DBF for DOS 3.3) LDA #$9D ;($BE00 for BASIC.SYSTEM, which will... STA RSTVCTH ;...be inserted here before this code... EOR #$A5 ;...is relocated) STA RSTVCTV END RTS END