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PRORWTS.S
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PRORWTS.S
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;open/read/write binary file in ProDOS filesystem
;copyright (c) Peter Ferrie 2013-16
!cpu 6502
!to "prorwts",plain
*=$800
;constants
cmdread = 1 ;requires enable_write=1
cmdwrite = 2 ;requires enable_write=1
SETKBD = $fe89
SETVID = $fe93
DEVNUM = $bf30
PHASEOFF = $c080
MOTOROFF = $c088
MOTORON = $c089
Q6L = $c08c
Q6H = $c08d
Q7L = $c08e
Q7H = $c08f
MLI = $bf00
KEY_POINTER = $11 ;ProDOS constant
EOF = $15 ;ProDOS constant
AUX_TYPE = $1f ;ProDOS constant
ROMIN = $c081
LCBANK2 = $c089
CLRAUXRD = $c002
CLRAUXWR = $c004
;options
enable_floppy = 0 ;set to 1 to enable floppy drive support
poll_drive = 0 ;set to 1 to check if disk is in drive
override_adr = 0 ;set to 1 to require an explicit load address
aligned_read = 0 ;set to 1 if all reads can be a multiple of block size
enable_write = 0 ;set to 1 to enable write support
;file must exist already and its size cannot be altered
;writes occur in multiples of block size (256 bytes for floppy, 512 bytes for HDD)
allow_multi = 0 ;set to 1 to allow multiple floppies
check_checksum=0 ;set to 1 to enforce checksum verification for floppies
allow_subdir = 0 ;set to 1 to allow opening subdirectories to access files
might_exist = 0 ;set to 1 if file is not known to always exist already
;makes use of status to indicate success or failure
allow_aux = 0 ;set to 1 to allow read/write directly to/from aux memory
;requires load_high to be set for arbitrary memory access
;else driver must be running from same memory target
;i.e. running from main if accessing main, running from aux if accessing aux
load_high = 0 ;load into banked RAM instead of main RAM
lc_bank = 1 ;load into specified bank (1 or 2) if load_high=1
;zpage usage
!if enable_floppy=1 {
tmpsec = $3c
reqsec = $3d
} ;enable_floppy
!if enable_floppy=1 {
curtrk = $40
} ;enable_floppy
command = $42 ;ProDOS constant
unit = $43 ;ProDOS constant
adrlo = $44 ;ProDOS constant
adrhi = $45 ;ProDOS constant
bloklo = $46 ;ProDOS constant
blokhi = $47 ;ProDOS constant
!if aligned_read=0 {
secsize = $46
secsize1 = $47
secsize2 = $48
} ;aligned_read
!if might_exist=1 {
status = $f3 ;returns non-zero on error
} ;might_exist
!if allow_aux=1 {
auxreq = $f4 ;set to 1 to read/write aux memory, else main memory is used
} ;allow_aux
sizelo = $f5 ;set if enable_write=1 and writing
sizehi = $f6 ;set if enable_write=1 and writing
entries = $f7 ;(internal) total number of entries
reqcmd = $f8 ;set (read/write) if enable_write=1
;if allow_multi=1, bit 7 selects floppy drive in current slot (clear=drive 1, set=drive 2)
ldrlo = $f9 ;set to load address if override_adr=1
ldrhi = $fa ;set to load address if override_adr=1
namlo = $fb ;name of file to access
namhi = $fc ;name of file to access
!if enable_floppy=1 {
step = $fd ;(internal) state for stepper motor
tmptrk = $fe ;(internal) temporary copy of current track
phase = $ff ;(internal) current phase for seek
!if enable_write=1 {
!if load_high=1 {
reloc = $d000 ;$300 bytes code, $100 bytes data
dirbuf = reloc+$400
encbuf = dirbuf+$200
} else { ;load_high
reloc = $bc00 ;$300 bytes code, $100 bytes data
dirbuf = reloc-$200
encbuf = dirbuf-$100
} ;load_high
} else { ;enable_write
!if load_high=1 {
reloc = $d000 ;$200 bytes code, $100 bytes data
dirbuf = reloc+$300
} else { ;load_high
reloc = $bd00 ;$200 bytes code, $100 bytes data
dirbuf = reloc-$200
} ;load_high
} ;enable_write
} else { ;enable_floppy
!if load_high=1 {
reloc = $d000 ;$200 bytes code
!if aligned_read=0 {
dirbuf = reloc+$200
} else { ;aligned_read
dirbuf = reloc+$100
} ;aligned_read
} else { ;load_high
reloc = $be00 ;$200 bytes code
!if aligned_read=0 {
dirbuf = reloc-$200
} else { ;aligned_read
dirbuf = reloc-$100
} ;aligned_read
} ;load_high
} ;enable_floppy
init jsr SETVID
jsr SETKBD
lda DEVNUM
sta x80_parms+1
sta unrunit+1
and #$70
!if (enable_floppy+enable_write)=2 {
sta unrslot1+1
sta unrslot2+1
sta unrslot3+1
sta unrslot4+1
} ;enable_floppy and enable_write
pha
!if enable_floppy=1 {
ora #<PHASEOFF
sta unrseek+1
ora #<MOTOROFF
!if might_exist=1 {
sta unrdrvoff1+1
} ;might_exist
sta unrdrvoff2+1
tax
inx ;MOTORON
!if poll_drive=1 {
stx unrdrvon1+1
} ;poll_drive
stx unrdrvon2+1
inx ;DRV0EN
!if allow_multi=1 {
stx unrdrvsel+1
} ;allow_multi
inx
inx ;Q6L
stx unrread1+1
!if poll_drive=1 {
stx unrread2+1
stx unrread3+1
} ;poll_drive
stx unrread4+1
stx unrread5+1
!if check_checksum=1 {
stx unrread6+1
} ;check_checksum
} ;enable_floppy
ldx #1
stx namlo
inx
stx namhi
jsr MLI
!byte $c7
!word c7_parms
ldx $200
dex
stx sizelo
bmi +++
readblock jsr MLI
!byte $80
!word x80_parms
lda #<(readbuff+4)
sta bloklo
lda #>(readbuff+4)
sta blokhi
inextent ldy #0
lda (bloklo), y
pha
and #$d0
;watch for subdirectory entries
cmp #$d0
bne +
lda (bloklo), y
and #$0f
tax
iny
-- lda (bloklo), y
cmp (namlo), y
beq ifoundname
;match failed, move to next directory in this block, if possible
-
+ pla
clc
lda bloklo
adc #$27
sta bloklo
bcc +
;there can be only one page crossed, so we can increment instead of adc
inc blokhi
+ cmp #<(readbuff+$1ff) ;4+($27*$0d)
lda blokhi
sbc #>(readbuff+$1ff)
bcc inextent
;read next directory block when we reach the end of this block
lda readbuff+2
ldx readbuff+3
bcs +
ifoundname iny
dex
bne --
lda (namlo), y
cmp #'/'
bne -
tya
eor #$ff
adc sizelo
sta sizelo
clc
tya
adc namlo
sta namlo
pla
and #$20
bne ++
ldy #KEY_POINTER+1
lda (bloklo), y
tax
dey
lda (bloklo), y
!if enable_floppy=1 {
sta unrblocklo+1
stx unrblockhi+1
} ;enable_floppy
sta unrhddblocklo+1
stx unrhddblockhi+1
+ sta x80_parms+4
stx x80_parms+5
++ lda sizelo
bne readblock
+++ pla
lsr
lsr
lsr
tax
lsr
ora #$c0
ldy $bf11, x
cpy #$c8 ;max slot+1
bcs set_slot
tya
set_slot sta slot+2
sta unrentry+2
!if enable_floppy=1 {
ldx #>unrelocdsk
ldy #<unrelocdsk
slot lda $cfff
sta unrentry+1
php
beq copydrv
ldx #>unrelochdd
ldy #<unrelochdd
copydrv stx blokhi
sty bloklo
!if load_high=1 {
!if lc_bank=1 {
lda LCBANK2
lda LCBANK2
} else { ;lc_bank
lda ROMIN
lda ROMIN
} ;lc_bank
} ;load_high
ldx #>((bit2tbl-opendir)+$ff)
ldy #0
- lda (bloklo), y
reladr sta reloc, y
iny
bne -
inc blokhi
inc reladr+2
dex
bne -
plp
bne ++
ldx #$16
-- stx bloklo
txa
asl
bit bloklo
beq +
ora bloklo
eor #$ff
and #$7e
- bcs +
lsr
bne -
tya
sta nibtbl-$16, x
!if enable_write=1 {
txa
ora #$80
sta xlattbl, y
} ;enable_write
iny
+ inx
bpl --
++ rts
} else { ;enable_floppy
slot lda $cfff
sta unrentry+1
!if load_high=1 {
!if lc_bank=1 {
lda LCBANK2
lda LCBANK2
} else { ;lc_bank
lda ROMIN
lda ROMIN
} ;lc_bank
} ;load_high
ldy #0
- lda unrelochdd, y
sta reloc, y
lda unrelochdd+$100, y
sta reloc+$100, y
iny
bne -
rts
} ;enable_floppy
c7_parms !byte 1
!word $200
x80_parms !byte 3, $d1
!word readbuff, 2
!if enable_floppy=1 {
unrelocdsk
!pseudopc reloc {
opendir ;read volume directory key block
unrblocklo=unrelocdsk+(*-reloc)
ldx #2
unrblockhi=unrelocdsk+(*-reloc)
lda #0
jsr readdirsel
;include volume directory header in count
readdir
!if might_exist=1 {
ldx dirbuf+37
inx
stx entries
} ;might_exist
firstent lda #<(dirbuf+4)
sta bloklo
lda #>(dirbuf+4)
sta blokhi
nextent ldy #0
!if might_exist=1 {
sty status
} ;might_exist
lda (bloklo), y
!if (might_exist+allow_subdir)>0 {
and #$f0
!if might_exist=1 {
;skip deleted entries without counting
beq ++
} ;might_exist
} ;might_exist or allow_subdir
!if allow_subdir=1 {
;subdirectory entries are seedlings
;but we need to distinguish between them later
cmp #$d0
beq savetype
} ;allow_subdir
;watch for seedling and saplings only
cmp #$30
bcs +
;remember type
savetype
!if allow_subdir=1 {
asl
asl
} else { ;allow_subdir
cmp #$20
} ;allow_subdir
php
;match name lengths before attempting to match names
lda (bloklo), y
and #$0f
tax
inx
!byte $2c
- lda (bloklo), y
cmp (namlo), y
beq foundname
;match failed, check if any directory entries remain
plp
+
!if might_exist=1 {
dec entries
bne ++
nodisk
unrdrvoff1=unrelocdsk+(*-reloc)
lda MOTOROFF
inc status
rts
} ;might_exist
;move to next directory in this block, if possible
++ clc
lda bloklo
adc #$27
sta bloklo
bcc +
;there can be only one page crossed, so we can increment instead of adc
inc blokhi
+ cmp #<(dirbuf+$1ff) ;4+($27*$0d)
lda blokhi
sbc #>(dirbuf+$1ff)
bcc nextent
;read next directory block when we reach the end of this block
ldx dirbuf+2
lda dirbuf+3
jsr readdirsec
bne firstent
foundname iny
dex
bne -
stx entries
!if enable_write=1 {
ldy reqcmd
cpy #cmdwrite ;control carry instead of zero
bne +
;round requested size up to nearest sector if writing
;or nearest block if using aligned reads
lda sizelo
!if aligned_read=0 {
beq +
inc sizehi
} else { ;aligned_read
ldx sizehi
jsr round
sta sizehi
} ;aligned_read
+
} ;enable_write
;cache EOF (file size, loaded backwards)
ldy #EOF+1
lda (bloklo), y
!if (enable_write+aligned_read)>0 {
tax
} else { ;enable_write or aligned_read
sta sizehi
} ;enable_write or aligned_read
dey
lda (bloklo), y
!if (enable_write+aligned_read)>0 {
;round file size up to nearest sector if writing without aligned reads
;or nearest block if using aligned reads
!if aligned_read=0 {
bcc ++
beq +
inx
lda #0
} else { ;aligned_read
!if enable_write=1 {
jsr round
tax
} else { ;enable_write
adc #$fe
txa
adc #1
and #$fe
} ;enable_write
} ;aligned_read
;set requested size to min(length, requested size)
!if enable_write=1 {
+ cpx sizehi
bcs +
++ stx sizehi
+
} else { ;enable_write
sta sizehi
} ;enable_write
} ;enable_write or aligned_read
!if aligned_read=0 {
sta sizelo
} ;aligned_read
;cache AUX_TYPE (load offset for binary files)
!if override_adr=0 {
!if allow_subdir=1 {
pla
tax
} else { ;allow_subdir
plp
} ;allow_subdir
ldy #AUX_TYPE
lda (bloklo), y
pha
iny
lda (bloklo), y
pha
!if allow_subdir=1 {
txa
pha
} ;allow_subdir
} ;override_adr
;cache KEY_POINTER
ldy #KEY_POINTER
lda (bloklo), y
tax
sta dirbuf
iny
lda (bloklo), y
sta dirbuf+256
;read index block in case of sapling
!if allow_subdir=1 {
plp
bpl rdwrfile
php
jsr readdirsec
plp
} else { ;allow_subdir
!if override_adr=1 {
plp
} ;override_adr
bcc rdwrfile
jsr readdirsec
} ;allow_subdir
;restore load offset
rdwrfile
!if override_adr=1 {
ldx ldrhi
lda ldrlo
} else { ;override_adr
pla
tax
pla
} ;override_adr
!if allow_subdir=1 {
;check file type and fake size and load address for subdirectories
bcc +
ldy #2
sty sizehi
ldx #>dirbuf
lda #<dirbuf
+
} ;allow_subdir
sta adrlo
stx adrhi
!if allow_aux=1 {
ldx auxreq
jsr setaux
} ;allow_aux
!if enable_write=1 {
ldy reqcmd
sty command
} ;enable_write
rdwrloop
!if aligned_read=0 {
;set read/write size to min(length, $200)
lda sizelo
ldx sizehi
cpx #2
bcc +
lda #0
ldx #2
+ sta secsize1
stx secsize2
} ;aligned_read
;fetch data block and read/write it
ldy entries
inc entries
ldx dirbuf, y
lda dirbuf+256, y
jsr seekrdwr
!if aligned_read=0 {
;if low count is non-zero then we are done
;(can happen only for partial last block)
lda secsize1
bne rdwrdone
;if count is $1xx then we are done
;(can happen only for partial last block)
dec sizehi
beq rdwrdone
;loop while size-$200 is non-zero
dec sizehi
lda sizehi
ora sizelo
} else { ;aligned_read
;loop while size-$200 is non-zero
dec sizehi
dec sizehi
} ;aligned_read
bne rdwrloop
unrdrvoff2=unrelocdsk+(*-reloc)
rdwrdone lda MOTOROFF
!if allow_aux=1 {
ldx #0
setaux sta CLRAUXRD, x
sta CLRAUXWR, x
} ;allow_aux
seekret rts
;no tricks here, just the regular stuff
seek sty step
asl phase
txa
asl
copy_cur tax
sta tmptrk
sec
sbc phase
beq +++
bcs +
eor #$ff
inx
bcc ++
+ sbc #1
dex
++ cmp step
bcc +
lda step
+ cmp #8
bcs +
tay
sec
+ txa
pha
ldx step1, y
+++ php
bne +
--- clc
lda tmptrk
ldx step2, y
+ stx tmpsec
and #3
rol
tax
lsr
unrseek=unrelocdsk+(*-reloc)
lda PHASEOFF, x
-- ldx #$13
- dex
bne -
dec tmpsec
bne --
bcs ---
plp
beq seekret
pla
inc step
bne copy_cur
step1 !byte 1, $30, $28, $24, $20, $1e, $1d, $1c
step2 !byte $70, $2c, $26, $22, $1f, $1e, $1d, $1c
readadr
- jsr readd5aa
cmp #$96
bne -
ldy #3
- sta curtrk
jsr readnib
rol
sta tmpsec
jsr readnib
and tmpsec
dey
bne -
rts
readd5aa
-- jsr readnib
- cmp #$d5
bne --
jsr readnib
cmp #$aa
bne -
tay ;we need Y=#$AA later
readnib
unrread1=unrelocdsk+(*-reloc)
- lda Q6L
bpl -
rts
!if (enable_write+aligned_read)=2 {
round clc
adc #$ff
txa
adc #1
and #$fe
rts
} ;enable_write and aligned_read
readdirsel ldy #0
sty adrlo
!if aligned_read=0 {
sty secsize1
} ;aligned_read
!if allow_multi=1 {
asl reqcmd
bcc seldrive
iny
seldrive lsr reqcmd
unrdrvsel=unrelocdsk+(*-reloc)
cmp DRV0EN, y
} ;allow_multi
!if poll_drive=1 {
sty status
unrdrvon1=unrelocdsk+(*-reloc)
ldy MOTORON
unrread2=unrelocdsk+(*-reloc)
- ldy Q6L
bpl -
unrread3=unrelocdsk+(*-reloc)
- cpy Q6L
bne readdirsec
inc status
bne -
pla
pla
jmp nodisk
} ;poll_drive
readdirsec ldy #>dirbuf
sty adrhi
!if aligned_read=0 {
ldy #2
sty secsize2
} ;aligned_read
ldy #cmdread
sty command
;convert block number to track/sector
seekrdwr
unrdrvon2=unrelocdsk+(*-reloc)
ldy MOTORON
lsr
txa
ror
lsr
lsr
sta phase
txa
and #3
php
asl
plp
rol
sta reqsec
!if aligned_read=0 {
;set read size to min(first size, $100) and then read address
ldy #0
lda secsize2
bne +
ldy secsize1
+ sty secsize
dec secsize2
} ;aligned_read
jsr readadr
;if track does not match, then seek
ldx curtrk
cpx phase
beq checksec
jsr seek
;force sector mismatch
lda #$ff
;match or read/write sector
checksec jsr cmpsec
!if aligned_read=0 {
;return if less than one sector requested
tya
bne readret
;return if only one sector requested
lda secsize1
cmp secsize2
beq readret
sta secsize
} ;aligned_read
inc reqsec
inc reqsec
;force sector mismatch
cmpsecrd lda #$ff
cmpsec
!if enable_write=1 {
ldy command
cpy #cmdwrite ;we need Y=2 below
beq encsec
} ;enable_write
cmpsec2 cmp reqsec
beq readdata
jsr readadr
beq cmpsec2
;read sector data
readdata jsr readd5aa
eor #$ad ;zero A if match
;; bne * ;lock if read failure
unrread4=unrelocdsk+(*-reloc)
- ldx Q6L
bpl -
eor nibtbl-$96, x
sta bit2tbl-$aa, y
iny
bne -
unrread5=unrelocdsk+(*-reloc)
-- ldx Q6L
bpl --
eor nibtbl-$96, x
sta (adrlo), y ;the real address
iny
!if check_checksum=1 {
!if aligned_read=0 {
bne check_end
} else { ;aligned_read
bne --
} ;aligned_read
unrread6=unrelocdsk+(*-reloc)
- ldx Q6L
bpl -
eor nibtbl-$96, x
bne cmpsecrd
} ;check_checksum
!if aligned_read=0 {
check_end
cpy secsize
bne --
ldy #0
} ;aligned_read
-- ldx #$a9
- inx
beq --
lda (adrlo), y
lsr bit2tbl-$aa, x
rol
lsr bit2tbl-$aa, x
rol
sta (adrlo), y
iny
!if aligned_read=0 {
cpy secsize
} ;aligned_read
bne -
readret inc adrhi
rts
!if enable_write=1 {
encsec
-- ldx #$aa
- dey
lda (adrlo), y
lsr
rol bit2tbl-$aa, x
lsr
rol bit2tbl-$aa, x
sta encbuf, y
lda bit2tbl-$aa, x
and #$3f
sta bit2tbl-$aa, x
inx
bne -
tya
bne --
cmpsecwr jsr readadr
cmp reqsec
bne cmpsecwr
;skip tail #$DE #$AA #$EB some #$FFs ...
ldy #$24
- dey
bpl -
;write sector data
unrslot1=unrelocdsk+(*-reloc)
ldx #$d1
lda Q6H, x ;prime drive
lda Q7L, x ;required by Unidisk
tya
sta Q7H, x
ora Q6L, x
;40 cycles
ldy #4 ;2 cycles
cmp $ea ;3 cycles
cmp ($ea,x) ;6 cycles
- jsr writenib1 ;(29 cycles)
;+6 cycles
dey ;2 cycles
bne - ;3 cycles if taken, 2 if not
;36 cycles
;+10 cycles
ldy #(prolog_e-prolog) ;2 cycles