dos33fsprogs/mist/qkumba_popwr.s
Vince Weaver 1de2b95073 mist: start adding qkumba's write routines
though hit a roadblock because I have no idea what they are doing
2020-07-25 23:14:01 -04:00

210 lines
4.9 KiB
ArmAsm

; popwr -- code provided by qkumba
; !cpu 6502
; !to "popwr",plain
; *=$d500
;bit2tbl=$dc00 ; in loader.s
encbuf=$e00
frombuff=$d00
popwr:
lda #$60
and #$70 ; the slot number is in the top here
sta slotpatchw1+1 ; self modify the code
sta slotpatchw2+1
sta slotpatchw3+1
sta slotpatchw4+1
; convert the input to nibbles?
ldy #2 ; why start at 2?
aa:
ldx #$aa
b1:
dey
frombuff_smc:
lda frombuff, 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 b1
tya
bne aa
; look for the proper sector to write
cmpsecwr:
b2:
jsr readd5aa ; look for dd55aa marker
cmp #$96
bne b2
ldy #3 ; try getting the sector number
b3:
jsr readnib
rol
sta tmpsec
jsr readnib
and tmpsec ; and with prev nibble?
dey
bne b3
;reqsec:
tay
bne cmpsecwr ; retry if not what we want?
;skip tail #$DE #$AA #$EB some #$FFs ...
ldy #$24
b4:
dey
bpl b4
; c0e0 slot 6 ph0 off
; c0e1 slot 6 ph0 on
; c0e2 slot 6 ph1 off
; c0e3 slot 6 ph1 on
; c0e4 slot 6 ph2 off
; c0e5 slot 6 ph2 on
; c0e6 slot 6 ph3 off
; c0e7 slot 6 ph3 on
; c0e8 slot 6 motor off
; c0e9 slot 6 motor on
; c0ea slot 6 drive 1
; c0eb slot 6 drive 2
; c0ec slot 6 q6 off read
; c0ed slot 6 q6 on wp sense
; c0ee slot 6 q7 off read/wp sense
; c0ef slot 6 q7 on write
; write sector data
slotpatchw1:
ldx #$d1
lda $c08d, x ; prime drive ; c0ed if X=$60
lda $c08e, x ; required by Unidisk ; c0ee
tya
sta $c08f, x ; c0ef write
ora $c08c, x ; c0ec read?
;40 cycles
ldy #4 ; 2 cycles
cmp $ea ; 3 cycles
cmp ($ea,x) ; 6 cycles
b5:
jsr writenib1 ; (29 cycles)
; +6 cycles
dey ; 2 cycles
bne b5 ; 3 cycles if taken, 2 if not
; 36 cycles
; +10 cycles
ldy #(prolog_e-prolog)
; 2 cycles
cmp $ea ; 3 cycles
b6:
lda prolog-1, y ; 4 cycles
jsr writenib3 ; (17 cycles)
; 32 cycles if branch taken
; +6 cycles
dey ; 2 cycles
bne b6 ; 3 cycles if taken, 2 if not
;36 cycles on first pass
;+10 cycles
tya ;2 cycles
ldy #$56 ;2 cycles
b7: eor bit2tbl-1, y ;5 cycles
tax ;2 cycles
lda xlattbl, x ;4 cycles
slotpatchw2:
ldx #$d1 ;2 cycles
sta $c08d, x ;5 cycles
lda $c08c, x ;4 cycles
;32 cycles if branch taken
lda bit2tbl-1, y ;5 cycles
dey ;2 cycles
bne b7 ;3 cycles if taken, 2 if not
;32 cycles
;+9 cycles
clc ;2 cycles
b88: eor encbuf, y ;4 cycles
b8: tax ;2 cycles
lda xlattbl, x ;4 cycles
slotpatchw3:
ldx #$d1 ;2 cycles
sta $c08d, x ;5 cycles
lda $c08c, x ;4 cycles
bcs f1 ;3 cycles if taken, 2 if not
;32 cycles if branch taken
lda encbuf, y ;4 cycles
iny ;2 cycles
bne b88 ;3 cycles if taken, 2 if not
;32 cycles
;+10 cycles
sec ;2 cycles
bcs b8 ;3 cycles
;32 cycles
;+3 cycles
f1: ldy #(epilog_e-epilog)
;2 cycles
cmp ($ea,x) ;6 cycles
b9: lda epilog-1, y ;4 cycles
jsr writenib3 ;(17 cycles)
;32 cycles if branch taken
;+6 cycles
dey ;2 cycles
bne b9 ;3 cycles if branch taken, 2 if not
lda $c08e, x
lda $c08c, x
lda $c088, x
rts
writenib1:
cmp ($ea,x) ;6 cycles
cmp ($ea,x) ;6 cycles
writenib3:
slotpatchw4:
ldx #$d1 ;2 cycles
writenib4:
sta $c08d, x ;5 cycles
ora $c08c, x ;4 cycles
rts ;6 cycles
prolog: .byte $ad, $aa, $d5
prolog_e:
epilog: .byte $ff, $eb, $aa, $de
epilog_e:
xlattbl:
.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