mirror of
https://github.com/JorjBauer/aiie.git
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1112 lines
33 KiB
NASM
1112 lines
33 KiB
NASM
.feature labels_without_colons
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.feature leading_dot_in_identifiers
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.feature c_comments
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.P02 ; normal 6502
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.macro ADR val
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.addr val
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.endmacro
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.macro BLT val
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BCC val
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.endmacro
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.macro BGE val
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BCS val
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.endmacro
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; Force APPLE 'text' to have high bit on; Will display as NORMAL characters
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.macro ASC text
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.repeat .strlen(text), I
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.byte .strat(text, I) | $80
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.endrep
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.endmacro
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.struct iob_t
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type .byte ; table type (always $01)
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slot .byte ; slot (<<4)
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drive .byte ; drive (1/2)
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volume .byte ; volume ($00 = all)
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track .byte
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sector .byte
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dct .word ; low/hi pointer to a DCT
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data .word ; low/hi pointer to sector data
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unused .word
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bytes .word ; # bytes to read/write ($00 == 256)
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command .byte ; 0=seek, 1=read, 2=write, 4=fmt
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retval .byte ; return code
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retvol .byte ; return volume
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retslot .byte ; return slot
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retdrive .byte ; return drive
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.endstruct
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a_cr = $0d ; Carriage return.
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RWTS_GETIOB = $03E3 ; low returned in Y, high A ($B7E8 is the normal IOB)
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RWTS = $03D9 ; needs IOB address in Y/A
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DOS33_IOB = $B7E8
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IOB = DOS33_IOB
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DOS33_SECBUF = $B4BB ; $B4BB-B5BA
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RWTS_WRTDIR = $B037 ; hidden routine in DOS to call RWTS (cf. AAL Vol2, iss 8)
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RWTS_WRTCMD = $B041 ; ... which wants to call write by default and we modify it to do something else
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F8ROM_YXHEX = $F940
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F8ROM_AXHEX = $F941
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F8ROM_XHEX = $F944 ; print X register in hex -- kills X,A
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F8ROM_AHEX = $FDDA ; print A register in hex
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F8ROM_INIT = $FB2F
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F8ROM_HOME = $FC58 ; Kills A,Y
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F8ROM_CROUT = $FC62 ; carriage return out
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F8ROM_MONWAIT = $FCA8 ; wait for (A*A*2.5 + A*13.5 + 7) * 0.980 usec
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F8ROM_COUT = $FDED ; Load A with character to print
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F8ROM_RDKEY = $FD0C
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WRVEC = $03D0 ; warm re-entry point
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PHSOFF = $C080
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PHSON = $C081
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DISKOFF = $C088
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DISKON = $C089
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DRIVEA = $C08A
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DISK_LATCHR = $C08C
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DISK_LATCHW = $C08D
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DISK_MODER = $C08E
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DISK_MODEW = $C08F
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;; Zero-page addresses used
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;; Totally free and clear: 6,7,8,9; eb,ec,ed,ee,ef;fa,fb,fc,fd
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ZP_STORPTR = $06 ;06,07
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ZP_STOR2 = $08 ;08,09
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ZP_SCRATCH = $eb ;just eb
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ZP_TRANSP = $ec ;ec,ed
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DST = $ee ;ee,ef
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ZP_SECTP = $fa ;fa,fb
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ZP_PRINT = $fc ;fc, fd
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.segment "CODE"
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START
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JMP Entry
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Entry
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PHP ;save interrupt state
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SEI ;disable interrupts
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JSR F8ROM_INIT
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JSR F8ROM_HOME
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JSR Prtmsg
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ASC "Insert a blank floppy in s6d1 and press a key..."
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.byte $8D, $00
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JSR F8ROM_RDKEY ; wait for a keypress
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;; set up pointers to SECDATA and TRANS62
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LDA #>SECDATA
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STA ZP_SECTP+1
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LDA #<SECDATA
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STA ZP_SECTP
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LDA #>TRANS62 ; set up ZP_TRANSP to point at TRANS62
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STA ZP_TRANSP+1 ; (a 64-byte lookup table)
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LDA #<TRANS62
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STA ZP_TRANSP
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;; initialize the buffer to start, so we can see what's going on
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;; DEBUGGING *** - don't really need to do this
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LDA #$FE
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STA VALUE
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LDA #>NYBDATA
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STA DST+1
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LDA #<NYBDATA
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STA DST
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LDA #$00
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STA CNT
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LDA #$1A
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STA CNT+1
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JSR memset
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;; Turn on motor for slot 6, drive 1
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LDX #$60 ; slot 6
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LDA DISKON,X
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LDA DRIVEA,X
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;; and seek out to track 0
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JSR RecalibrateTrack
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;; Wait for it to come to speed
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JSR WaitMotor
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;; write 40 tracks of data
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LDA #$00
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@writeAnotherTrack
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JSR WriteOneTrack ; takes track number in A and preserves it
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CLC
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ADC #1
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CMP #35
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BNE @writeAnotherTrack
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;; Turn off motor for slot 6, drive 1 and let RWTS turn it back on
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LDX #$60 ; slot 6
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LDA DISKOFF,X
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@rwtstest
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;; using RWTS, validate the sector contents of each sector on the track
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;;
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;; call RWTS to perform the read
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;; Reset the current track
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JSR RecalibrateTrack
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;; Let RWTS think we're changing slots, so it doesn't use any cached
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;; data about the head position
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LDA #$70
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STA DOS33_IOB+iob_t::retslot
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LDA #01
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STA RWTS_WRTCMD ; set read command
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;; Pick track/sector to read
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LDA #$00
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STA $B397 ; track
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LDA #$00
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STA $B398 ; sector
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@readAnotherSector
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LDA $B397
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JSR F8ROM_AHEX
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LDA $B398
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JSR F8ROM_AHEX
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JSR Prtmsg
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ASC " :Reading track/sector"
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.byte $00
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JSR RWTS_WRTDIR
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;; check for an error (detail is in IOB + $0D)
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BCC @noErrors
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JMP rwtsTestsFailed
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@noErrors
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;; Generate the expected block of data so we can validate the sector
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LDA $B397
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STA TARGETTRK
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LDA $B398
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STA TARGETSEC
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JSR MakeSectorData
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;; compare SECDATA against the RWTS sector buffer at DOS33_SECBUF
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LDA TARGETSEC
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JSR F8ROM_AHEX
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JSR Prtmsg
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ASC " : validate sector contents"
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.byte $00
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JSR Seccmp
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BCC @cmpok
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JMP FailedSectorCompare
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@cmpok
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;; *** Something is wrong with the IOB+iob::sector approach -- if I hard code addresses for track/sector this works, but if I use the :: struct mechanism is doesn't
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;; *** ... and the T/S offsets don't match the IOB header, so I'm not
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;; *** sure why storing them at these addresses works - need more
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;; *** RWTS info
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;; *** https://www.txbobsc.com/aal/1982/aal8205.html#a6
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;; Read the next sector
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INC $B398
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LDA $B398
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CMP #$10
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BEQ @nextTrack
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JMP @readAnotherSector
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@nextTrack
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LDA #$00
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STA $B398
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INC $B397
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LDA $B397 ;track
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CMP #$23
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BEQ @doneReadTest
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JMP @readAnotherSector
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@doneReadTest
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;; Find sector # 6 (arbitrarily chosen) and replace its data
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;; with 256 bytes of 0xFF (nybbles 0xFF 0x96 0x96 0x96 ... )
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;; ...
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;; using RWTS, validate the sector contents of all 16 sectors again
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;; ...
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TestsDone
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JSR Prtmsg
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ASC "Test complete, no errors found."
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.byte $00
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Exit
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PLP ;restore interrupts
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LDA #$00
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STA $48 ; RWTS: needs to be cleared after calls
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;; for debugging, show where the sector and nybble data are
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LDA #>SECDATA
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JSR F8ROM_AHEX
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LDA #<SECDATA
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JSR F8ROM_AHEX
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JSR Prtmsg
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ASC " : sector data buffer"
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.byte $00
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LDA #>NYBDATA
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JSR F8ROM_AHEX
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LDA #<NYBDATA
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JSR F8ROM_AHEX
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JSR Prtmsg
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ASC " : nybble data buffer"
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.byte $00
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;; Fix DOS where we butchered it
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LDA #02
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STA RWTS_WRTCMD ; reset command to original value ("write")
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;; Turn off motor for slot 6, drive 1 before exiting
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LDX #$60 ; slot 6
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LDA DISKOFF,X
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JMP WRVEC ; done; warm-start for the user
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rwtsTestsFailed
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LDA IOB+iob_t::retval ; get return code from our IOB
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JSR F8ROM_AHEX ; print it
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JSR Prtmsg
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ASC " : error reported during RWTS... stopping"
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.byte $00
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JMP Exit
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WriteProtected
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JSR Prtmsg
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ASC "Disk is write protected; aborting"
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.byte $00
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JMP Exit
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FailedSectorCompare
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JSR Prtmsg
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ASC "Sector comparison failed"
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.byte $00
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JMP Exit
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;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; Start of subroutines
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;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; Prtmsg: display text on screen, using inline
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;; null-terminated strings. Trashes A,X,Y, ZP_PRINT, ZP_PRINT+1.
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;; Adds a newline at the end of the string. Strings may be
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;; arbitrarily long. Expects the string to have the high bit
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;; set where necessary; passes the characters directly to COUT.
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Prtmsg
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PLA
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STA ZP_PRINT
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PLA
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STA ZP_PRINT+1
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LDY #$00
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@LoopA
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INY
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BNE @noinc
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INC $FD
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@noinc
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TYA
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PHA
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LDA (ZP_PRINT),Y
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BEQ @done
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JSR F8ROM_COUT
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PLA
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TAY
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JMP @LoopA
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@done
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PLA
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CLC
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TYA
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ADC ZP_PRINT
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TAX
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LDA ZP_PRINT+1
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ADC #$00
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PHA
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TXA
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PHA
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JSR F8ROM_CROUT
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RTS
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;; WaitMotor: delay to wait for a drive to come up to speed
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WaitMotor
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LDA #$EF
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STA WAITCTR
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LDA #$D8
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STA WAITCTR+1
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@LoopA LDY #$12
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@LoopB DEY
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BNE @LoopB
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INC WAITCTR
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BNE @LoopA
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INC WAITCTR+1
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BNE @LoopA
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RTS
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;; MoveTrack: move from CURHALFTRK to DSTHALFTRK
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;; Note that those are (as the names imply) half-tracks; be
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;; sure to multiply actual track numbers by two
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MoveTrack
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LDA CURHALFTRK
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CMP DSTHALFTRK
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BNE @MoreWork
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RTS ; all done, return
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@MoreWork
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BCC @MoveUp ; If we want to move up, then go there
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;; otherwise fall through to movedown
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@MoveDown
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DEC CURHALFTRK
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JMP @MoveHead
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@MoveUp
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INC CURHALFTRK
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@MoveHead
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LDA CURHALFTRK ;compute phase number for new track
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AND #$03
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ASL
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ORA #$60 ; slot number 6
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TAY
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LDA PHSON,Y ; turn on phase to move
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LDA #$56
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JSR F8ROM_MONWAIT ; delay for physical action
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LDA PHSOFF, Y ; turn off phase
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JMP MoveTrack ; and see if there's more work to do
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;; RecalibrateTrack: make sure we're on track 0 by moving more tracks
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;; (outward) than exist on the drive
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RecalibrateTrack
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LDA #$80 ; move more half-tracks than exist
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STA CURHALFTRK
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LDA #$00
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STA DSTHALFTRK
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JMP MoveTrack
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;; EraseTrack: Write 0x3000 nybbles of 0xFF to the current track.
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;; Assumes disk is running and up to speed, and on the destination
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;; track already.
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;; Tromps A, Y, and zero-page ZP_SCRATCH
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;; FIXME: need to be sure EraseTrack does not span pages or the timing
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;; will be broken
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EraseTrack
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LDA #$30 ; 0x3000 nybbles to write
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STA NYBCOUNT
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LDX #$60 ; Slot 6
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LDA DISK_LATCHW,X
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LDA DISK_MODER,X
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BPL @NOTWP
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JMP WriteProtected ; Disk is write protected, so bail
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@NOTWP
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LDA #$FF ; nybble data to write
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STA DISK_MODEW,X
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CMP DISK_LATCHR,X ;4
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BIT ZP_SCRATCH ;+3=7
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LDY #$00 ;+2=9
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@LoopA
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DEC ZP_SCRATCH ;+5=14
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NOP ;+2=16
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@LoopB ; (always 16 here)
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DEC ZP_SCRATCH ;+5=21
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CMP $FFFF ;+4=25
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NOP ;+2=27
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STA DISK_LATCHW,X ;+5=32
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CMP DISK_LATCHR,X ;4
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DEY ;+2=6
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BNE @LoopA ;+3 (branch)=9 or +2=8
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DEC NYBCOUNT ;8+5=13
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BNE @LoopB ;+3(branch)=16 or +2=15
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JSR @rts ; waste +12=27
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DEC ZP_SCRATCH ;+5=32
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LDA DISK_MODER,X
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LDA DISK_LATCHR,X
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@rts
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RTS
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;; WriteTrack: write <6656 ($1A00) nybbles to the current track.
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;; Assumes drive is on and up to speed, and on the right track.
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;; The data to write is at NYBDATA.
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;; FIXME: need to be sure WriteTrack does not span pages or the timing
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;; will be broken
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WriteTrack
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LDA #>NYBDATA ; set up ZP_STORPTR to the start of NYBDATA
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STA ZP_STORPTR+1
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LDA #<NYBDATA
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STA ZP_STORPTR
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;; Bytes must be sent to the controller precisely once every 32
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;; clock cycles.
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;;
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;; Copy <$1A00 bytes from (ZP_STORPTR) to the disk drive. We don't
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;; count the bytes - instead, there's a 00 sentinel at the end of
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;; the track data. When we get that, we branch to @doneWriting.
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LDX #$60 ; Slot 6
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LDA DISK_LATCHW,X
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LDA DISK_MODER,X
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BPL @NOTWP
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JMP WriteProtected ; Disk is write protected, so bail
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@NOTWP
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LDY #$00
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LDA (ZP_STORPTR),Y
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STA DISK_MODEW,X
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;; Start of timing critical section: one byte every 32 cycles
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CMP DISK_LATCHR,X ; Start of first write... 4
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JSR @rts ; waste +12 cycles = 16
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NOP ; +2 = 18
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@loopA ;coming in to loopA, we're at 18
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NOP ; +2 = 20
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NOP ; +2 = 22
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CMP $00 ; waste +3 cycles = 25
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@loopB ;coming in to loopB, we're at 25
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NOP ; +2 = 27
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STA DISK_LATCHW,X ;+5 = 32
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CMP DISK_LATCHR,X ; Start of new write... 4
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INY ;+2=6
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BEQ @nextPage ; +2 (no branch)=8/+3 (branch)=9
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@LoadNext
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LDA (ZP_STORPTR),Y ;8+5=13
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BEQ @doneWriting ;+2=15 / +3=16
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JMP @loopA ;+3=18
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@nextPage
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INC ZP_STORPTR+1 ;9+6=15
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LDA (ZP_STORPTR),Y ;+5=20
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BEQ @doneWriting2 ;+2=22 / +3=23
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JMP @loopB ;+3=25
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@doneWriting ;coming in to @doneWriting we're at 16
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CMP $00 ; waste +3 = 19
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NOP ; +2 = 21
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NOP ; +2 = 23
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@doneWriting2 ; on entry here we're at 23
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NOP ; +2 = 25
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NOP ; +2 = 27
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NOP ; +2 = 29
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CMP $00 ; waste +3 = 32
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;; Need to hit exactly 32 cycles *before* this DISK_MODER read
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LDA DISK_MODER,X
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LDA DISK_LATCHR,X
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@rts
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RTS
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;; MakeTrackData: precompute a full track of nybblized data for
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;; track (A), and store it at NYBDATA ($2000).
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MakeTrackData
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STA TARGETTRK
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LDA #0
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STA TARGETSEC
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LDA #16
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STA SECCOUNT ; we want to write 16 sectors of nyb'd data
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LDA #>NYBDATA
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STA ZP_STORPTR+1 ; high address
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LDA #<NYBDATA
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STA ZP_STORPTR ; low address
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@NextSector
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JSR MakeSectorData ; will increment ZP_STORPTR by 388 as it goes
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INC TARGETSEC
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DEC SECCOUNT
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BNE @NextSector
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;; Stick a 00 at the end -- it's an illegal byte for writing to the
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;; disk controller, so we'll use it as the sentinel for when we've
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;; reached the end of the data to write
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LDY #$01
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LDA #$00
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STA (ZP_STORPTR),Y
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RTS
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;; MakeSectorData: Create one sector of nybblized data for
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;; track TARGETTRK, sector TARGETSEC and store it at
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;; ZP_STORPTR (low) +1 (high)
|
|
;; Increments ZP_STORPTR as it goes
|
|
;; trashes Y/A
|
|
MakeSectorData
|
|
LDA TARGETTRK
|
|
JSR F8ROM_AHEX
|
|
LDA TARGETSEC
|
|
JSR F8ROM_AHEX
|
|
JSR Prtmsg
|
|
ASC " : generate sector data"
|
|
.byte $00
|
|
|
|
LDY #16 ; write 16 sync bytes
|
|
LDA #$FF
|
|
@LoopA
|
|
DEY
|
|
STA (ZP_STORPTR),Y
|
|
CPY #00
|
|
BNE @LoopA
|
|
|
|
;; add 20 to ZP_STORPTR
|
|
LDA #16
|
|
CLC
|
|
ADC ZP_STORPTR
|
|
STA ZP_STORPTR
|
|
BCC @SectorHeader
|
|
INC ZP_STORPTR+1
|
|
@SectorHeader
|
|
;; Emit the sector header
|
|
LDY #$00
|
|
LDA #$D5 ; 3 bytes of header prolog
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
LDA #$AA
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
LDA #$96
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
|
|
LDA #$FF ; Volume number (255), 4-and-4 encoded
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
|
|
LDA TARGETTRK ; Track number, 4-and-4 encoded
|
|
JSR _Store44
|
|
LDA TARGETSEC ; Sector number, 4-and-4 encoded
|
|
JSR _Store44
|
|
|
|
LDA TARGETTRK ; compute checksum
|
|
EOR TARGETSEC
|
|
EOR #$FF ; (volume number)
|
|
JSR _Store44 ; Store it, 4-and-4 encoded
|
|
|
|
LDA #$DE ; Sector header epilog
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
LDA #$AA
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
LDA #$EB
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
|
|
;; 3 gap bytes
|
|
LDA #$FF
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
|
|
LDA #$D5 ; Data prolog
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
LDA #$AA
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
LDA #$AD
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
|
|
;; Add 20 to ZP_STORPTR
|
|
LDA ZP_STORPTR
|
|
CLC
|
|
ADC #20
|
|
STA ZP_STORPTR
|
|
BCC @SectorDataTime
|
|
INC ZP_STORPTR+1
|
|
|
|
@SectorDataTime
|
|
LDY #00
|
|
|
|
;; Now for the fun bit - 343 bytes of data! Prep a 256 byte sector
|
|
;; and then translate it to 6-and-2 encoding (plus checksum),
|
|
;; and store it at ZP_STORPTR
|
|
;;
|
|
;; The test sector data is the value of (track + sector),
|
|
;; incrementing 256 times. Easy to generate...
|
|
LDA TARGETTRK
|
|
CLC
|
|
ADC TARGETSEC
|
|
@SectorLoop
|
|
STA (ZP_SECTP),Y
|
|
TAX
|
|
INX
|
|
TXA
|
|
INY
|
|
BNE @SectorLoop ; store 256 bytes
|
|
|
|
;; Convert and store as 6-and-2 with checksum
|
|
JSR Encode6and2
|
|
;; Encode6and2 added 0x157 to ZP_STORPTR, so we don't have to
|
|
|
|
;; data epilog
|
|
LDY #$00
|
|
LDA #$DE ; Data prolog
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
LDA #$AA
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
LDA #$EB
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
|
|
;; add 3 bytes to ZP_STORPTR
|
|
LDA #$03
|
|
CLC
|
|
ADC ZP_STORPTR
|
|
BCC @finishnocarry
|
|
INC ZP_STORPTR+1
|
|
@finishnocarry
|
|
STA ZP_STORPTR
|
|
RTS
|
|
|
|
;; Store A in (ZP_STORPTR),Y with 4-and-4 encoding (2 bytes)
|
|
;; increments Y by 2, trashes A and ZP_SCRATCH
|
|
_Store44
|
|
STA ZP_SCRATCH
|
|
AND #$AA
|
|
LSR
|
|
ORA #$AA
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
|
|
LDA ZP_SCRATCH
|
|
AND #$55
|
|
ORA #$AA
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
RTS
|
|
|
|
;; Encode6and2: given 256 bytes of data at SECDATA, 6-and-2
|
|
;; encode it in to 0x156 nybble-bytes at (ZP_STORPTR) with a
|
|
;; 1-byte checksum after (== 0x157 total).
|
|
;; Trashes A and Y and X
|
|
;; Updates ZP_STORPTR
|
|
;; trashes ZP_STOR2, ZP_TRANSP, IDX6, IDX2, CKSUM,
|
|
;; ZP_SECTP
|
|
Encode6and2
|
|
LDA ZP_STORPTR ; set up ZP_STOR2 to point 256 bytes above
|
|
STA ZP_STOR2 ; ZP_STORPTR for convenience, since we're
|
|
LDY ZP_STORPTR+1 ; addressing an output buffer of > 0x100
|
|
INY ; bytes
|
|
STY ZP_STOR2+1
|
|
|
|
;; Clear output buffer 0x157 bytes
|
|
LDY #$00
|
|
LDA #$00
|
|
STA CKSUM ; convenient place to clear the checksum for later
|
|
@ClearLoop
|
|
STA (ZP_STORPTR),Y
|
|
CPY #$57 ; also clear at +0x100 if < 0x157
|
|
BLT @AlsoClearHigh ;Y < #$57? Branch
|
|
@ClearNext
|
|
INY
|
|
BEQ @ClearDone ; if Y became 0, we rolled over and are done
|
|
JMP @ClearLoop
|
|
@AlsoClearHigh
|
|
STA (ZP_STOR2),Y
|
|
JMP @ClearNext
|
|
@ClearDone
|
|
;; Work through the 256 bytes of data to construct the 6and2 data,
|
|
;; with ZP_SECTP as the input and ZP_STORPTR as the output
|
|
;;
|
|
LDA #$55
|
|
STA IDX2
|
|
;; for (idx6 = 0x0101; idx6 >= 0; idx6--)
|
|
LDA #$01
|
|
STA IDX6
|
|
STA IDX6+1 ; IDX6 = 0x0101
|
|
@WorkLoopA
|
|
LDY IDX6 ; val6 = input[idx6 & 0xFF]
|
|
LDA (ZP_SECTP),Y
|
|
STA VAL6
|
|
|
|
LDY IDX2 ; val2 = output[idx2];
|
|
LDA (ZP_STORPTR),Y
|
|
STA VAL2
|
|
|
|
;; val2 = (val2 << 1) | (val6 & 1); val6 >>= 1;
|
|
LSR VAL6+1
|
|
ROR VAL6 ; val6 >>= 1, and C = old (val6&1)
|
|
LDA VAL2
|
|
ROL ; A = (val2 << 1) | C
|
|
STA VAL2 ; val2 = all that jazz
|
|
|
|
;; another round of the same
|
|
LSR VAL6+1
|
|
ROR VAL6 ; val6 >>= 1, and C = old (val6&1)
|
|
LDA VAL2
|
|
ROL ; A = (val2 << 1) | C
|
|
STA VAL2 ; val2 = all that jazz
|
|
|
|
LDY IDX2 ; output[idx2] = val2
|
|
LDA VAL2
|
|
STA (ZP_STORPTR),Y
|
|
|
|
;; if (idx6 < 0x100) { output[0x56+idx6] = val6; }
|
|
LDA IDX6+1
|
|
CMP #01
|
|
BEQ @decidx2
|
|
LDA #$56
|
|
CLC
|
|
ADC IDX6
|
|
BCC @storeLT100
|
|
|
|
;; we need to store in ZP_STOR2 (the result overflowed)
|
|
TAY ; Y = idx6 + 0x56 and is >= 0x100
|
|
LDA VAL6
|
|
STA (ZP_STOR2),Y
|
|
JMP @decidx2
|
|
|
|
@storeLT100
|
|
TAY ; Y = idx6 + 0x56 and is < 0x100
|
|
LDA VAL6
|
|
STA (ZP_STORPTR),Y
|
|
JMP @decidx2
|
|
|
|
@decidx2
|
|
;; if (--idx2 < 0) { idx2 = 0x55; }
|
|
;; IDX2 never exceeds $55, so we can test using DEC and BMI/BPL
|
|
DEC IDX2
|
|
BPL @dontresetidx2
|
|
;; ... high bit is set, so we underflowed; reset IDX2 back to $55
|
|
|
|
LDA #$55
|
|
STA IDX2
|
|
@dontresetidx2
|
|
|
|
;; End of WorkLoopA: 16-bit decrement idx6, and loop to @WorkLoopA
|
|
;; if it is >= 0
|
|
LDA IDX6 ; sets Z if it's zero
|
|
BNE @simpledeclo ; if not zero, just decrement and continue
|
|
LDA IDX6+1 ; low was zero, so repeat w/ high
|
|
BEQ @DoneWorkloopA ; if high is also zero we're done
|
|
DEC IDX6+1
|
|
@simpledeclo
|
|
DEC IDX6
|
|
|
|
;; continue loop
|
|
JMP @WorkLoopA
|
|
|
|
;; Both IDX6 and IDX6+1 reached 0, so we are done the loop
|
|
@DoneWorkloopA
|
|
;; Mask out the "extra" 2-bit data:
|
|
;; output[0x54] &= 0x0F; output[0x55] &= 0x0F;
|
|
LDY #$54
|
|
LDA (ZP_STORPTR),Y
|
|
AND #$0F
|
|
STA (ZP_STORPTR),Y
|
|
INY
|
|
AND #$0F
|
|
STA (ZP_STORPTR),Y
|
|
|
|
;; Loop over the data one more time to construct the actual output
|
|
;; and compute the checksum
|
|
;; Checksum is initialized to 0 above
|
|
;; for (int idx6=0; idx6<0x156; idx6++)
|
|
LDA #$00
|
|
STA IDX6+1
|
|
STA IDX6
|
|
@WorkLoopB
|
|
LDY IDX6 ; val = output[idx]
|
|
LDA IDX6+1
|
|
EOR #$01
|
|
BEQ @LoadFromHi
|
|
LDA (ZP_STORPTR),Y
|
|
JMP @c
|
|
@LoadFromHi
|
|
LDA (ZP_STOR2),Y
|
|
@c
|
|
STA ZP_SCRATCH
|
|
|
|
;; output[idx] = _trans[cksum^val]
|
|
LDA CKSUM ; Y = cksum ^ val
|
|
EOR ZP_SCRATCH
|
|
TAY
|
|
LDA IDX6+1
|
|
EOR #$01 ; to set C for BEQ coming up
|
|
BEQ @StoreToHi ; branch based on EOR (if IDX6+1 == 1)
|
|
|
|
LDA (ZP_TRANSP),Y ; A = trans[cksum^val]
|
|
LDY IDX6 ; restore Y
|
|
STA (ZP_STORPTR),Y
|
|
JMP @d
|
|
@StoreToHi
|
|
LDA (ZP_TRANSP),Y ; A = trans[cksum^val]
|
|
LDY IDX6 ; restore Y
|
|
STA (ZP_STOR2),Y
|
|
@d
|
|
;; cksum = val;
|
|
LDA ZP_SCRATCH
|
|
STA CKSUM
|
|
|
|
;; Complete for loop: idx6++ and loop if idx6 < 0x156
|
|
INC IDX6
|
|
BEQ @incHigh
|
|
@f
|
|
LDA IDX6+1
|
|
EOR #$01
|
|
BNE @WorkLoopB ; high byte isn't set yet, so continue looping
|
|
LDA IDX6
|
|
CMP #$56
|
|
BGE @setCksum ; high byte set, and low >= 0x56 - done loop
|
|
JMP @WorkLoopB
|
|
@incHigh
|
|
INC IDX6+1
|
|
JMP @f
|
|
|
|
@setCksum
|
|
;; output[342] = _trans[cksum]
|
|
LDY CKSUM ; A = _trans[cksum]
|
|
LDA (ZP_TRANSP),Y
|
|
LDY #$56
|
|
STA (ZP_STOR2),Y ; output[0x100 + Y] = A
|
|
|
|
;; Add 0x157 to ZP_STORPTR (number of bytes we added to the buffer)
|
|
INC ZP_STORPTR+1 ; add 0x100
|
|
LDA ZP_STORPTR
|
|
CLC
|
|
ADC #$57
|
|
BCC @nocarry
|
|
INC ZP_STORPTR+1
|
|
@nocarry
|
|
STA ZP_STORPTR
|
|
|
|
@done
|
|
RTS
|
|
|
|
|
|
;; set CNT, CNT+1, DST, DST+1, VALUE before calling
|
|
memset
|
|
@a
|
|
LDY #0
|
|
LDA CNT
|
|
ORA CNT+1
|
|
BEQ @fin
|
|
LDA VALUE
|
|
STA (DST),y
|
|
INC DST
|
|
BNE @b
|
|
INC DST+1
|
|
@b
|
|
DEC CNT
|
|
LDA CNT
|
|
CMP #$FF
|
|
BNE @c
|
|
DEC CNT+1
|
|
@c
|
|
SEC
|
|
BCS @a
|
|
@fin
|
|
RTS
|
|
|
|
;; Seccmp: compare SECDATA and DOS33_SECBUF (256 bytes)
|
|
;; return with carry clear if compare is ok; set if differences are
|
|
;; found
|
|
Seccmp
|
|
LDA #>SECDATA
|
|
STA ZP_STORPTR+1
|
|
LDA #<SECDATA
|
|
STA ZP_STORPTR
|
|
LDA #>DOS33_SECBUF
|
|
STA ZP_STOR2+1
|
|
LDA #<DOS33_SECBUF
|
|
STA ZP_STOR2
|
|
|
|
LDY #$FF
|
|
@next
|
|
/*
|
|
TYA ;debug message - save Y before & restore after
|
|
PHA
|
|
JSR F8ROM_AHEX ;byte number
|
|
LDA (ZP_STORPTR),Y
|
|
JSR F8ROM_AHEX
|
|
LDA (ZP_STOR2),Y
|
|
JSR F8ROM_AHEX
|
|
JSR Prtmsg
|
|
ASC " : byte cmp"
|
|
.byte $00
|
|
PLA
|
|
TAY
|
|
*/
|
|
|
|
LDA (ZP_STORPTR),Y
|
|
SEC
|
|
SBC (ZP_STOR2),Y
|
|
BNE @doneError
|
|
|
|
TYA
|
|
BEQ @done ;if Y==0 we're done
|
|
DEY
|
|
JMP @next
|
|
|
|
@done
|
|
CLC ;no error
|
|
RTS
|
|
@doneError
|
|
SEC ;error
|
|
RTS
|
|
|
|
WriteOneTrack
|
|
;; Fill track with as many FF bytes as we think fit. Per
|
|
;; https://retrocomputing.stackexchange.com/questions/503/absolute-maximum-number-of-nibbles-on-an-apple-ii-floppy-disk-track
|
|
;; track 0 can't reasonably fit more than about 8300 nybbles, so
|
|
;; we will write 8400 nybbles to be sure to have cleared any possible
|
|
;; track (track 0 is the physically largest, on the outside of
|
|
;; the disk; so track 35 will be multiply covered easily).
|
|
|
|
PHA ; save A on the way in
|
|
STA TARGETTRK
|
|
|
|
;; postion the head for the traget track
|
|
ASL ; multiply by 2
|
|
STA DSTHALFTRK
|
|
JSR MoveTrack
|
|
|
|
;; Fill the track with 0xFF sync bytes (ensuring we've wiped the track)
|
|
JSR EraseTrack
|
|
|
|
;; Write out a track of nybblized sectors to Track 0 for physical
|
|
;; sectors 0 through 15. The data in each is algorithmic, same as
|
|
;; the wozzle test disk pattern test #7 -- 256 incrementing bytes
|
|
;; starting at (sector + track).
|
|
|
|
;; Precompute one track of nybblized data at NYBDATA for the given track
|
|
LDA TARGETTRK
|
|
JSR MakeTrackData
|
|
|
|
;; Write it to the track
|
|
JSR WriteTrack
|
|
PLA ; restore A on the way out
|
|
RTS
|
|
|
|
;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Start of data segment
|
|
;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; variable space
|
|
;;
|
|
;; Many/all of these could be zero-page and not here.
|
|
;; They also don't need to be initialized to zero so they
|
|
;; could just be memory locations instead of byte defines.
|
|
;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
WAITCTR
|
|
.byte $00, $00
|
|
|
|
CURHALFTRK
|
|
.byte $00
|
|
|
|
DSTHALFTRK
|
|
.byte $00
|
|
|
|
NYBCOUNT
|
|
.byte $00
|
|
|
|
TARGETTRK
|
|
.byte $00
|
|
TARGETSEC
|
|
.byte $00
|
|
SECCOUNT
|
|
.byte $00
|
|
|
|
IDX6
|
|
.byte $00, $00
|
|
IDX2
|
|
.byte $00
|
|
CKSUM
|
|
.byte $00
|
|
VAL2
|
|
.byte $00
|
|
VAL6
|
|
.byte $00
|
|
|
|
CNT
|
|
.byte $00, $00
|
|
VALUE
|
|
.byte $00
|
|
|
|
/*IOB
|
|
.tag iob_t*/
|
|
|
|
;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Block (read-only) data area
|
|
;;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
DCT
|
|
.byte $00 ; decide type ($00 = DiskII)
|
|
.byte $01 ; phases per track ($01 for DiskII)
|
|
.byte $EF, $D8 ; motor on time count ($EFD8 for DiskII)
|
|
|
|
.align 256
|
|
|
|
;; 6-and-2 DOS3.3 translation table (here so it doesn't
|
|
;; cross a page boundary)
|
|
TRANS62
|
|
.byte $96, $97, $9a, $9b, $9d, $9e, $9f, $a6
|
|
.byte $a7, $ab, $ac, $ad, $ae, $af, $b2, $b3
|
|
.byte $b4, $b5, $b6, $b7, $b9, $ba, $bb, $bc
|
|
.byte $bd, $be, $bf, $cb, $cd, $ce, $cf, $d3
|
|
.byte $d6, $d7, $d9, $da, $db, $dc, $dd, $de
|
|
.byte $df, $e5, $e6, $e7, $e9, $ea, $eb, $ec
|
|
.byte $ed, $ee, $ef, $f2, $f3, $f4, $f5, $f6
|
|
.byte $f7, $f9, $fa, $fb, $fc, $fd, $fe, $ff
|
|
|
|
;; scratch space for a sector of data
|
|
;; FIXME: is there an easier way to define a block so that
|
|
;; ca65 honors it and shows it properly in the lst?
|
|
.align 256
|
|
SECDATA
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
.byte $00, $00, $00, $00, $00, $00, $00, $00
|
|
|
|
;; nybblized data that we precalculate
|
|
;; and then write to the track; or that we read in from the track
|
|
;; and store here
|
|
.align 256
|
|
NYBDATA
|
|
.byte $00
|
|
|
|
|