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/ Apple II Magazines (PO) / Nibble Volume 11, No. 04 - 05 - 06 (1990)(MindCraft Publishing)[no boot].zip / Nibble Volume 11, No. 04 - 05 - 06 (1990)(MindCraft Publishing)[no boot].po / NIBBLE.1990:APR.VOL11.NO04 / PRODOS.LINKER.S < prev next >

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Text File | 1996-12-24 | 24KB | 767 lines

******************************** * PRODOS.LINKER Source Code * * by Mark Hadley * * Copyright (c) 1990 * * MondCraft Publ. Corp. * * Concord, MA 01742 * ******************************** * MINDCRAFT ASSEMBLER -- converted to Merlin-8 * ProDOS Equates EXTRNCMD EQU $BE06 ; External cmd JMP instruction ERROUT EQU $BE09 ; Error handler XTRNADDR EQU $BE50 ; Start of external cmd handler XLEN EQU $BE52 ; External cmd name length (-1) XCNUM EQU $BE53 ; Command # (0 for external) PBITS EQU $BE54 ; Command parameter bits FBITS EQU $BE56 ; Parameters found in pares APARM EQU $BE58 ; Address parameter specified SPARM EQU $BE61 ; Slot parameter specified DPARM EQU $BE62 ; Drive parameter specified GETBUFR EQU $BEF5 ; Get free space MLI EQU $BF00 ; Machine Language Interface BITMAP EQU $BF58 ; Protected memory locations * variables DESTPTR EQU $00 ; ZP pointer for prgm dest TSPTR EQU $02 ; ZP pointer for T/S list DATAPTR EQU $04 ; ZP pointer for data FLNMLEN EQU $250 ; Length of filename YTEMP EQU $251 ; Save Y-reg CMD EQU $252 ; Command (0-DLOAD, 1-DBLOAD) TRACK EQU $253 ; Track to read from SECTOR EQU $254 ; Sector to read from LENGTH EQU $255 ; Length of file PARMTBL EQU $257 ; Beginning of parameter table UNITNUM EQU $258 ; Code for slot/drive BUFFER EQU $259 ; Pointer to buffer to load at BLOCK EQU $25B ; Block to load from disk FILENAME EQU $25D ; Name of file to load * Other equates: A1L EQU $3C ; Beginning addr of move A2L EQU $3E ; Ending addr of move A4L EQU $42 ; Destination of move TXTTAB EQU $67 ; Start of Applesoft program VARTAB EQU $69 ; Start of simple variable space HIMEM EQU $73 ; Start of ProDOS buffer PRGEND EQU $AF ; End of Applesoft program IN EQU $200 ; Input buffer KBD EQU $C000 ; Keypress input KBSTROBE EQU $C010 ; Key-pressed status LINPRT EQU $ED24 ; Prints 16 bit hex as decimal CROUT EQU $FD8E ; Output a carriage return COUT EQU $FDED ; Output a character in Acc MOVE EQU $FE2C ; Move block of memory ORG $2000 * Resetve space for commands SEC ; Calcuate # pages to reserve LDA #>END100 SBC #>BEGIN STA PAGES JSR GETBUFR ; Open room for commands BCC INSTALL LDA #14 ; BASIC error: prgm too large JMP ERROUT ; Print error msg and quit INSTALL STA PGSTART ; Addr of freed space LDA EXTRNCMD+1 ; Must create link to STA NEXTCMD+1 ; any existing external LDA EXTRNCMD+2 ; commands STA NEXTCMD+2 LDA #0 ; Install commands STA EXTRNCMD+1 ; by storing the command LDA PGSTART ; handler address at STA EXTRNCMD+2 ; EXTRNCMD * Protect memory from ProDOS operations LDA PGSTART STA PRTCTPG ; Starting page to protect PROTECT LDA PRTCTPG ; Get page to protect JSR SETBIT INC PRTCTPG DEC PAGES ; Finished with all pages? BNE PROTECT ; No, keep going. * Relocate the command code LDX #0 LDA PGSTART ; Get the new page number SEC SBC #>BEGIN ; Offset to new location STA OFFSET LDA #<BEGIN ; Search for cmds to relocate STA $FE LDA #>BEGIN STA $FF LDY #0 RELOC1 LDA ($FE),Y CMP #$D9 ; CMP command? BEQ RELOC3 CMP #$20 ; JSR command? BEQ RELOC3 CMP #$4C ; JMP command? BEQ RELOC3 CMP #$B9 ; LDA command? BEQ RELOC3 CMP #$BD ; LDA,X command? BEQ RELOC3 INC $FE BNE RELOC2 INC $FF RELOC2 LDA $FF CMP #>END100 BNE RELOC1 JMP RELOC4 RELOC3 CLC LDA $FE ADC #2 STA $FE LDA $FF ADC #0 STA $FF LDA ($FE),Y CMP #>BEGIN ; Within bounds of program? BCC RELOC2 ; No, so don't change CMP #>END100 BCS RELOC2 ; No, so don't change ADC OFFSET ; Yes, change it STA ($FE,X) JMP RELOC2 ; and continue RELOC4 LDA #>BEGIN STA $FF LDA #<BEGIN STA $FE RELOC5 LDA ($FE),Y CMP #$A9 ; LDA command? BEQ RELOC7 RELOC6 INC $FE BNE RELOC5 BEQ RELOC8 RELOC7 INC $FE LDA ($FE),Y CMP #>BEGIN ; First page of program? BCC RELOC6 ; No, don't change it CMP #>END100 ; Less than last page? BCS RELOC7 ; No, don't change it ADC OFFSET ; Yes, change to new place STA ($FE),Y JMP RELOC6 ; and continue looking... RELOC8 EQU * * Move the code to final position LDA #<BEGIN STA A1L LDA #>BEGIN STA A1L+1 LDA #<END STA A2L LDA #>END STA A2L+1 LDA #0 STA A4L LDA PGSTART STA A4L+1 LDY #0 JSR MOVE ; Move the code and exit * Announce successful installation * and display commands and parameters LDY #0 MSGOUT LDA MSG,Y ; Get next character JSR COUT ; and print it INY CPY #MSGEND-MSG ; Finished? BNE MSGOUT ; Nope, keep going. RTS ; Yes, installation complete SETBIT PHA ; Acc holds high addr byte AND #$07 ; of memory page to protect TAX PLA LSR ; Upper five bits of Acc LSR ; make an index into LSR ; the bit map TAY LDA #0 ; Lower 3 bits of Acc SEC ; choose the bit to SETLP ROR ; be set. X-reg counts DEX ; while bit is shifted into BPL SETLP ; place from carry ORA BITMAP,Y STA BITMAP,Y ; Set the bit in bit map RTS PAGES DS 1 ; Length of command handler PGSTART DS 1 ; Start of command handler OFFSET DS 1 ; Offset to new location PRTCTPG DS 1 ; Next page to protect MSG HEX 8D8D ASC "ProDOS Linker Installed" HEX 8D ASC "COMMANDS:" HEX 8D ASC "DLOAD <NAME>[,S#][,D#]" HEX 8D ASC "DBLOAD <NAME>[,S#][,D#][,A ADDR]" HEX 8D ASC "DCAT [,S#][,D#]" HEX 8D8D MSGEND EQU * DS $2200-* ; (Fill 0's to page boundary) BEGIN EQU * ******************************** * Check for commands CLD ; Req'd as I.D. for external cmd LDY #0 LDX #0 CHKCMD LDA IN,X ; Get command character INX CMP #$A0 ; Is it a blank? BEQ CHKCMD ; If it is, ignore it CMP DLNAME,Y ; Same as DLOAD? BEQ CHKCMD1 ; Yes, continue to end CMP #$E0 ; Lower case? BCC NOTFOUND1 ; No, so try next AND #$DF ; Yes, convert to uppercase CMP DLNAME,Y ; OK now? BNE NOTFOUND1 ; No, so try next CHKCMD1 INY CPY #DLLEN-DLNAME ; At end? BNE CHKCMD ; No, so continue BEQ DLOAD ; Yes, so DLOAD requested NOTFOUND1 LDY #0 ; Try next command LDX #0 CHKCMD2 LDA IN,X INX CMP #$A0 BEQ CHKCMD2 CMP DBNAME,Y BEQ CHKCMD3 CMP #$E0 BCC NOTFOUND2 AND #$DF CMP DBNAME,Y BNE NOTFOUND2 CHKCMD3 INY CPY #DBLEN-DBNAME BNE CHKCMD2 BEQ DBLOAD ; DBLOAD requested NOTFOUND2 LDY #0 LDX #0 CHKCMD4 LDA IN,X ; Get command character INX CMP #$A0 ; Is it a blank? BEQ CHKCMD4 ; If it is, ignore it CMP DCNAME,Y ; Save as DCAT? BEQ CHKCMD5 ; Yes, continue to end CMP #$E0 ; Lower case? BCC NOTFOUND3 ; No, so exit AND #$DF ; Yes, convert to uppercase CMP DCNAME,Y ; OK now? BNE NOTFOUND3 ; No, so exit CHKCMD5 INY CPY #DCLEN-DCNAME ; At end? BNE CHKCMD4 ; No, so continue BEQ DCAT ; Yes, so DCAT requested NOTFOUND3 SEC ; Set carry to indicate failure NEXTCMD JMP $0000 ; Jump to next external cmd DLOAD JSR GETNAME ; Get filename after cmd LDA #$00 STA XCNUM ; Extername cmd number = 0 LDA #<EXECUTE ; Store return address STA XTRNADDR ; for BASIC.SYSTEM LDA #>EXECUTE STA XTRNADDR+1 * Set up parsing rules for DLOAD LDA #$10 ; Pathname is not required STA PBITS LDA #$04 ; Allow slot and drive parms STA PBITS+1 LDA #$00 STA CMD ; DLOAD command active CLC ; Command recognized RTS ; Let BASIC.SYSTEM do parsing DBLOAD JSR GETNAME ; Get filename after cmd LDA #0 STA XCNUM ; Externale cmd number = 0 LDA #<EXECUTE ; Set return address STA XTRNADDR ; for BASIC SYSTEM LDA #>EXECUTE STA XTRNADDR+1 * Set up parsing rules LDA #$10 ; Pathname not required STA PBITS LDA #$84 ; Address, Slot, Drive parms STA PBITS+1 ; allowed LDA #$01 STA CMD ; DBLOAD command active CLC ; Command recognized RTS ; Let BASIC.SYSTEM do parsing DCAT DEY ; Length of command STY XLEN LDA #0 STA XCNUM ; External cmd number = 0 LDA #<EXECAT ; Set return address STA XTRNADDR ; for BASIC.SYSTEM LDA #>EXECAT STA XTRNADDR+1 * Set parsing rules for DCAT LDA #$10 ; Pathname not required STA PBITS LDA #$04 ; Slot, Drive parms allowed STA PBITS+1 CLC ; Command recognized RTS ; Let BASIC.SYSTEM do parsing * Find filename in DIS 3.3 directory EXECUTE JSR SETPARMS ; Set up MLI parameters JSR CHECKPRO ; Check for ProDOS disk LDA #3 ; Set # parms for READ_BLOCK STA PARMTBL LDA #$11 ; Track containing DOS directory STA TRACK LDA #$0F ; Sector of directory start STA SECTOR NEXTDIR CLC ; Load in data buffer JSR READTS ; Get start of directory LDA #$0B ; Position of first entry STA DATAPTR NXTENTRY LDY #0 ; Track of t/x list LDA (DATAPTR),Y CMP #$FF ; If file is deleted, skip it BEQ NOTFILE LDY #3 ; Start of filename LDX #0 CHKFLNM LDA (DATAPTR),Y CMP FILENAME,X BNE NOTFILE INY INX CPX FLNMLEN BCC CHKFLNM CPX #30 ; If filename 30 chars ling BEQ GOTFILE ; then file is correct one LDA (DATAPTR),Y ; If next character is space, CMP #$A0 ; then file is correct one BEQ GOTFILE NOTFILE CLC LDA DATAPTR ADC #$23 ; Move to next entry STA DATAPTR BCC NXTENTRY LDY #0 ; Must get next sector LDA #1 STA DATAPTR LDA (DATAPTR),Y ; Track of next directory BEQ FLNOTFND ; If 0, then no such file STA TRACK INY LDA (DATAPTR),Y ; Sector of next directory STA SECTOR BPL NEXTDIR ; Always branch FLNOTFND LDA #7 ; BASIC error: path not found SEC ; Flag error RTS ; Let BASIC.SYSTEM report error * File found, make sure it si right type GOTFILE LDY #2 ; Location of file type LDA (DATAPTR),Y AND #$0F ; Remove locked indicator LDX CMD ; Looking for Applesoft file? BEQ CHKAPLS ; Yes, so branch CMP #4 ; check for Binary file BEQ TYPEOK ; File is correct type BADTYPE LDA #$0D ; BASIC err: file type mismatch SEC ; Flag error RTS ; Let BASIC.SYSTEM report error CHKAPLS CMP #2 ; Check for Applesoft file BNE BADTYPE ; Error if not right TYPEOK EQU * ; Type is what we're looking for * Find and load file's T/S sector LDY #0 ; Track of file's T/S LDA (DATAPTR),Y STA TRACK INY ; Sector of file's T/S LDA (DATAPTR),Y STA SECTOR SEC ; Load into T/S buffer JSR READTS * Load file's first data sector LDY #$0C ; Track of first file sector LDA (TSPTR),Y STA TRACK INY ; Sector of first file sector LDA (TSPTR),Y STA SECTOR INY STY YTEMP CLC ; Load to data buffer JSR READTS ; Get the first sector LDA CMD ; Working on Applesoft file? BEQ APLSOFT ; Yes, so branch LDY #0 ; Find where file goes LDA (DATAPTR),Y STA DESTPTR INY LDA (DATAPTR),Y STA DESTPTR+1 LDA FBITS+1 ; Now check if addr specified BPL ADDROK ; Not specified LDA APARM ; Specified, so get it STA DESTPTR LDA APARM+1 STA DESTPTR+1 ADDROK INY ; Location of file length LDA (DATAPTR),Y STA LENGTH INY LDA (DATAPTR),Y STA LENGTH+1 INY JMP LOADFILE ; Now go move file into memory APLSOFT LDA TXTTAB ; Start of Applesoft program STA DESTPTR LDA TXTTAB+1 STA DESTPTR+1 LDY #0 ; Location of file length LDA (DATAPTR),Y STA LENGTH INY LDA (DATAPTR),Y STA LENGTH+1 INY * Load the file into memory LOADFILE LDX #0 ; No pre-index needed LDA (DATAPTR),Y ; Get byte of file STA (DESTPTR,X) ; Store it in memory INC DESTPTR BNE NOINC INC DESTPTR+1 NOINC SEC ; For subtraction LDA LENGTH SBC #1 STA LENGTH LDA LENGTH+1 SBC #0 STA LENGTH+1 BNE CONT ; Check if LENGTH = 0 LDA LENGTH BEQ DONE ; Finished loading file! CONT INY ; Move to next sector? BNE LOADFILE ; Still in same sector LDY YTEMP ; Get back T/S index LDA (TSPTR),Y ; Next track STA TRACK INY LDA (TSPTR),Y ; Next sector STA SECTOR INY STY YTEMP CLC ; Load into data buffer JSR READTS ; Get next sector LDY YTEMP ; Should next T/S be loaded? BNE SAMETS ; No, keep this T/S list LDY #2 ; Yes, get linking track, sector LDA (TSPTR),Y ; Link track STA TRACK INY LDA (TSPTR),Y ; Link sector STA SECTOR LDY #$0C ; Next file sector STY YTEMP SEC ; Load into T/S buffer JSR READTS ; Get next T/S list SAMETS LDY #0 JMP LOADFILE ; Continue loading file * Done loading! Finish up Applesoft load. DONE LDA CMD BNE GOODEXIT ; DBLOAD, so all is done LDA DESTPTR ; Tell Applesoft where prgm ends STA PRGEND LDA DESTPTR+1 STA PRGEND+1 INC DESTPTR BNE NOINC2 INC DESTPTR+1 NOINC2 LDA DESTPTR ; Also set beginning of simple STA VARTAB ; variable space at end of LDA DESTPTR+1 ; program STA VARTAB+1 GOODEXIT CLC ; No errors RTS ; Return to BASIC.SYSTEM * Catalog DOS 3.3 disk EXECAT JSR SETPARMS ; Set up MLI parameters JSR CHECKPRO ; Check for ProDOS disk LDA #3 ; Set # parms for READ_BLOCK STA PARMTBL JSR CROUT LDA #$11 ; Track of directory STA TRACK LDA #$0F ; Sector of directory STA SECTOR LDA #0 ; To keep track of # listed, STA DESTPTR ; DESTPTR temp. used NEXTSEC CLC ; Load into DATA buffer JSR READTS LDA #$0B ; First entry in directory STA DATAPTR NXTFILE LDY #0 ; Track of file data LDA (DATAPTR),Y ; = $FF if deleted BNE CHKDEL ; Not end of directory LDY #3 LDA (DATAPTR),Y BEQ DONECAT ; If first name chr=0, then done CHKDEL CMP #$FF ; Is file deleted? BEQ SKIPDEL ; Don't list if deleted LDX #" " ; Assume file unlocked LDY #2 ; Position of file type, lock LDA (DATAPTR),Y ; Is file locked? BPL NOLOCK ; No, print space LDX #"*" ; Yes, print asterisk NOLOCK TXA JSR COUT ; Print lock status LDA (DATAPTR),Y AND #$0F ; Ignore lock, unknown types TAX LDA TYPESYMB,X ; Symbol to display (T,I,A,B) JSR COUT LDA #" " JSR COUT LDY #$21 ; Position of file size (sectors) LDA (DATAPTR),Y JSR PRNTSIZE ; Convert to decimal and display LDA #" " JSR COUT LDY #3 ; Beginning of file name PRNTNAME LDA (DATAPTR),Y ; Get character of name BEQ DONENAME ; If zero, then name is finished JSR COUT ; Print the character INY CPY #$21 ; Max filename length 30 characters BCC PRNTNAME DONENAME JSR CROUT INC DESTPTR ; Check if 20 names listed LDA DESTPTR CMP #20 BNE SKIPDEL ; Continue of not 20 CHKEY LDA KBD ; Wait for keypress BPL CHKEY ; No keypress BIT KBSTROBE ; Clear key pressed status CMP #$83 ; CTRL-C? BEQ DONECAT ; Yes, halt catalog LDA #0 ; Reset # cataloged to 0 STA DESTPTR SKIPDEL CLC LDA DATAPTR ; Move to next entry ADC #$23 STA DATAPTR BCC NXTFILE ; Continue in this directory LDY #1 ; Track of next directory LDA (DATAPTR),Y STA TRACK INY ; Sector of next directory LDA (DATAPTR),Y BEQ DONECAT ; If zero, then CAT is done STA SECTOR JMP NEXTSEC * Done with DCAT! Clean up the mess... DONECAT JSR CROUT CLC ; No errors RTS ; Ride off into the sunset * Find filename and save it GETNAME LDA IN,X ; Get next character CMP #$A0 ; Is it blank? BNE GTNM2 ; No, part of file name INX BNE GETNAME ; Always branch GTNM2 LDY #0 GTNM3 LDA IN,X ; Get character CMP #$8D ; End of command? BEQ GOTNAME CMP #"," ; End of file name? BEQ GOTNAME STA FILENAME,Y INY INX BNE GTNM3 ; Always branch GOTNAME STY FLNMLEN ; Store length of file name DEX ; Save command + name length so STX XLEN ; ProDOS ignores DOS filename RTS * Convert track/sector into block and load it READTS PHP ; Save carry flag for later LDA HIMEM ; Find buffer to load to STA BUFFER LDA HIMEM+1 BCS TSBUF ; Skip next if for T/S buffer ADC #2 ; Set buffer to DATA buffer TSBUF STA BUFFER+1 LDA TRACK ASL ; Multiply track # by 8 ASL ASL STA BLOCK LDA #0 STA BLOCK+1 ROL BLOCK+1 ; Shift carry bit into BLOCK+1 LDY SECTOR ; Find relative block number LDA RELBLOCK,Y ; containing desired sector CLC ADC BLOCK ; Add relative block to base STA BLOCK JSR MLI DFB $80 ; READ_BLOCK DA PARMTBL BCS READERR ; Bad news if carry set LDY SECTOR ; Find half of block to read LDA BLKHALF,Y ; contains sector PLP ; Recover carry flag BCC DTBUF ; If clear, set up DATAPTR CLC ADC BUFFER+1 STA TSPTR+1 LDA #0 STA TSPTR BEQ READDONE DTBUF ADC BUFFER+1 STA DATAPTR+1 LDA #0 STA DATAPTR READDONE RTS READERR PLA ; Pop return addr, status PLA PLA LDA #8 ; Other erros reported as SEC ; BASIC.SYSTEM I/O ERROR RTS * Set parameters for READ_BLOCK command SETPARMS LDA SPARM ; Get slot specified ASL ; Slot * 16 ASL ASL ASL LDX DPARM ; Get drive specified CPX #2 ; Drive 2? BNE SAVEUNIT ORA #$80 ; Set bit for drive 2 SAVEUNIT STA UNITNUM ; Store slot/drive as unit # RTS * Make sure disk is not ProDOS disk CHECKPRO LDA #2 ; Set # parms for ON_LINE STA PARMTBL LDA #<IN STA BUFFER LDA #>IN STA BUFFER+1 JSR MLI ; Do ON_LINE command DFB $C5 ; Code for ON_LINE DA PARMTBL CMP #$52 ; MLI error: not ProDOS disk BEQ NOPRO ; That's what we want! TAX ; Save error code in X PLA ; Pop off return addr from stack PLA LDA #3 ; Assume error; no device CPX #$28 ; MLI error: no device BEQ SKIPIO ; If no device, don't print I/O LDA #8 ; Other error, flag as I/O error SKIPIO SEC NOPRO RTS ; Return to BASIC or command * Convert filesize to decimal and display it PRNTSIZE TAX ; Copy filesize to X-reg LDA #"0" ; Load Acc with ASCII 0 CPX #100 ; Is it greater than 100? BCS NOZERO ; Yes, don't print leading zeros CPX #10 ; Is it greater than 10? BCS ONEZERO ; Yes, only one leading zero JSR COUT ; Print 1 of 2 leading zeros ONEZERO JSR COUT ; Print a leading 0 * LINPRT converts hex number in X-reg (low) and * Acc (high) into decimal number and displays it, * therefore Acc must be 0 and X-reg is filesize NOZERO LDA #0 JMP LINPRT ; Display filesize * relative block numbers for sector computations RELBLOCK DFB 0,7,6,6,5,5,4,4 DFB 3,3,2,2,1,1,0,7 * Locate half of block containing sector BLKHALF DFB 0,0,1,0,1,0,1,0 DFB 1,0,1,0,1,0,1,1 * Filetype symbols TYPESYMB ASC "TIA B " ; 11 spaces after B * Command names DLNAME ASC "DLOAD" DLLEN EQU * DBNAME ASC "DBLOAD" DBLEN EQU * DCNAME ASC "DCAT" DCLEN EQU * END EQU * END100 EQU END+$100 ; For relocating routine