how to make your own version
This commit is contained in:
Peter Ferrie
parent
da6232ca8d
commit
30571429ad
|
|
@ -0,0 +1,231 @@
|
|||
;aPLib data decompressor for Apple II
|
||||
;Peter Ferrie (peter.ferrie@gmail.com)
|
||||
;assemble using ACME
|
||||
;src<dst
|
||||
!cpu 6502
|
||||
!to "aplib",plain
|
||||
*=$d000
|
||||
|
||||
;unpacker variables, no need to change these
|
||||
src = $0
|
||||
dst = $2
|
||||
ecx = $4
|
||||
last = $6
|
||||
tmp = $8
|
||||
|
||||
lda #>pakoff
|
||||
sta src+1
|
||||
lda #<pakoff
|
||||
sta src
|
||||
lda #0
|
||||
sta dst+1
|
||||
sta dst
|
||||
sta last
|
||||
sta ecx+1
|
||||
jsr unpack
|
||||
tay ;returns A=0
|
||||
- lda $d600, y
|
||||
sta $bf00, y
|
||||
iny
|
||||
bne -
|
||||
ldx $2b
|
||||
stx $bfd6 ;set current slot in RWTS
|
||||
stx $bfe4 ;set previous slot in RWTS
|
||||
ldx #$16
|
||||
-- stx src
|
||||
txa
|
||||
asl
|
||||
bit src
|
||||
beq +
|
||||
ora src
|
||||
eor #$ff
|
||||
and #$7e
|
||||
- bcs +
|
||||
lsr
|
||||
bne -
|
||||
tya
|
||||
sta $fa80, x ;regenerate tables
|
||||
txa
|
||||
ora #$80
|
||||
sta $fa29, y ;regenerate tables
|
||||
iny
|
||||
+ inx
|
||||
bpl --
|
||||
tax ;A=FF
|
||||
txs ;clean stack
|
||||
jmp $dd84 ;DOS entrypoint
|
||||
|
||||
unpack ;unpacker entrypoint
|
||||
|
||||
literal
|
||||
jsr getput
|
||||
ldy #2
|
||||
|
||||
nexttag
|
||||
jsr getbit
|
||||
bcc literal
|
||||
jsr getbit
|
||||
bcc codepair
|
||||
jsr getbit
|
||||
bcs onebyte
|
||||
jsr getsrc
|
||||
lsr
|
||||
beq donedepacking
|
||||
ldx #0
|
||||
stx ecx
|
||||
rol ecx
|
||||
stx last+1
|
||||
tax
|
||||
bne domatch_with_2inc
|
||||
|
||||
getbit
|
||||
asl last
|
||||
bne .stillbitsleft
|
||||
jsr getsrc
|
||||
asl
|
||||
sta last
|
||||
inc last
|
||||
|
||||
.stillbitsleft
|
||||
|
||||
donedepacking
|
||||
rts
|
||||
|
||||
onebyte
|
||||
ldy #1
|
||||
sty ecx
|
||||
iny
|
||||
lda #0
|
||||
sta tmp+1
|
||||
lda #$10
|
||||
|
||||
.getmorebits
|
||||
pha
|
||||
jsr getbit
|
||||
pla
|
||||
rol
|
||||
bcc .getmorebits
|
||||
bne domatch
|
||||
jsr putdst
|
||||
|
||||
linktag
|
||||
bne nexttag
|
||||
|
||||
codepair
|
||||
jsr getgamma
|
||||
- jsr dececx
|
||||
dey
|
||||
bne -
|
||||
tay
|
||||
ora ecx+1
|
||||
beq +
|
||||
|
||||
normalcodepair
|
||||
dey
|
||||
sty last+1
|
||||
jsr getsrc
|
||||
tax
|
||||
!byte $a9
|
||||
+ iny
|
||||
jsr getgamma
|
||||
cpy #$7d
|
||||
bcs domatch_with_2inc
|
||||
cpy #5
|
||||
bcs domatch_with_inc
|
||||
txa
|
||||
bmi domatch_new_lastpos
|
||||
tya
|
||||
bne domatch_new_lastpos
|
||||
|
||||
domatch_with_2inc
|
||||
inc ecx
|
||||
bne domatch_with_inc
|
||||
inc ecx+1
|
||||
|
||||
domatch_with_inc
|
||||
inc ecx
|
||||
bne domatch_new_lastpos
|
||||
inc ecx+1
|
||||
|
||||
domatch_new_lastpos
|
||||
|
||||
domatch_lastpos
|
||||
ldy #1
|
||||
lda last+1
|
||||
sta tmp+1
|
||||
txa
|
||||
|
||||
domatch
|
||||
sta tmp
|
||||
lda src+1
|
||||
pha
|
||||
lda src
|
||||
pha
|
||||
lda dst
|
||||
clc
|
||||
adc tmp
|
||||
sta src
|
||||
lda dst+1
|
||||
adc tmp+1
|
||||
sta src+1
|
||||
- jsr getput
|
||||
jsr dececx
|
||||
ora ecx+1
|
||||
bne -
|
||||
pla
|
||||
sta src
|
||||
pla
|
||||
sta src+1
|
||||
bne linktag
|
||||
|
||||
getgamma
|
||||
lda #1
|
||||
sta ecx
|
||||
sta ecx+1
|
||||
dec ecx+1
|
||||
|
||||
.getgammaloop
|
||||
jsr getbit
|
||||
rol ecx
|
||||
rol ecx+1
|
||||
jsr getbit
|
||||
bcs .getgammaloop
|
||||
rts
|
||||
|
||||
dececx
|
||||
lda ecx
|
||||
bne +
|
||||
dec ecx+1
|
||||
+ dec ecx
|
||||
lda ecx
|
||||
rts
|
||||
|
||||
getput
|
||||
jsr getsrc
|
||||
|
||||
putdst
|
||||
pha
|
||||
lda dst
|
||||
bne +
|
||||
dec dst+1
|
||||
+ dec dst
|
||||
pla
|
||||
sty tmp
|
||||
ldy #0
|
||||
sta (dst), y
|
||||
ldy tmp
|
||||
rts
|
||||
|
||||
getsrc
|
||||
lda src
|
||||
bne +
|
||||
dec src+1
|
||||
+ dec src
|
||||
sty tmp
|
||||
ldy #0
|
||||
lda (src), y
|
||||
ldy tmp
|
||||
rts
|
||||
|
||||
!bin "d600-ffff.rev.pak.rev"
|
||||
pakoff
|
||||
|
|
@ -0,0 +1,15 @@
|
|||
How to make your own version:
|
||||
|
||||
Take a regular version of Diversi-DOS, and save the $BF00-BFFF and $D700-FFFF regions to disk.
|
||||
Make whatever changes you will to that image.
|
||||
Fill the following regions with zeroes in the $D700 region:
|
||||
- the read buffer at $1DBC-1FFF;
|
||||
- the translate tables at offsets $2329-2368 and $2396-23FF (the unpacker will regenerate them);
|
||||
- the write buffer at $2500-2655
|
||||
Concatenate the two images, with the $BF00 region first (to create a file named "d600-ffff").
|
||||
Reverse the order of the bytes in the image (to create a file named "d600-ffff.rev").
|
||||
Compress the result with aPLib ("appack c d600-ffff.rev d600-ffff.rev.pak").
|
||||
Remove the $18 bytes header from the resulting file. The file size must not exceed $1F00 bytes!
|
||||
Reverse the order of the bytes in the image (to create a file named "d600-ffff.rev.pak.rev").
|
||||
Build the unpacker code with ACME. The compressed image will be linked automatically to the output file.
|
||||
Write the output file to disk, beginning with T00 S01.
|
||||
Loading…
Reference in New Issue