cc65/libsrc/geos-cbm/disk/dio_cts.s

188 lines
4.3 KiB
ArmAsm

;
; 2001-07-02, Maciej 'YTM/Elysium' Witkowiak
; 2015-08-26, Greg King
;
;
; unsigned char __fastcall__ dio_phys_to_log (dhandle_t handle,
; dio_phys_pos *physpos, /* input */
; unsigned *sectnum); /* output */
;
.export _dio_phys_to_log
.export sectab_1541_l, sectab_1541_h ; for log_to_phys
.import popax,__oserror
.importzp ptr1,ptr2,ptr3,tmp1,tmp2,tmp3,tmp4
.include "dio.inc"
.include "geossym.inc"
.include "const.inc"
_dio_phys_to_log:
sta ptr1
stx ptr1+1 ; pointer to result
jsr popax
sta ptr2
stx ptr2+1 ; pointer to input structure
jsr popax
sta ptr3
stx ptr3+1 ; pointer to handle
ldy #sst_flag
lda (ptr3),y
and #128
beq _inv_hand ; handle not open or invalid
ldy #diopp_head
lda (ptr2),y
bne _inv_data ; there is only head 0
ldy #diopp_track
lda (ptr2),y
beq _inv_data ; there is no track 0
sta tmp1
iny
lda (ptr2),y
bne _inv_data ; there are no more than 256 tracks
dec tmp1 ; normalize track to start from 0
ldy #diopp_sector
lda (ptr2),y
sta tmp2
iny
lda (ptr2),y
bne _inv_data ; there are no more than 256 sectors
; tmp1 (int) holds track+sector, translate it using device info
ldy #sst_driveno
lda (ptr3),y
tay
lda driveType,y
and #%00001111 ; remove ramDisk flags
cmp #DRV_1541
beq dio_cts1541
cmp #DRV_1571
beq dio_cts1571
cmp #DRV_1581
beq dio_cts1581
lda #INCOMPATIBLE ; unsupported device
ldx #0
beq ret
dio_ctsend:
ldy #1
lda tmp2
sta (ptr1),y
dey
lda tmp1
sta (ptr1),y
ldx #0
txa
ret:
sta __oserror
rts ; return success
; errors
_inv_data:
lda #INV_TRACK
.byte $2c
_inv_hand:
lda #DEV_NOT_FOUND
ldx #0
beq ret
; device-depended stuff, tmp1=track-1, tmp2=sector
dio_cts1541:
ldy tmp1
cpy #35
bcs _inv_data
lda sectab_1541_l,y
clc
adc tmp2
sta tmp1
lda sectab_1541_h,y
adc #0
sta tmp2
jmp dio_ctsend
dio_cts1571:
lda tmp1
cmp #70
bcs _inv_data
cmp #35 ; last track of one side
bcs _sub35
jmp dio_cts1541 ; track <=35 - same as 1541
_sub35:
sec
sbc #35
sta tmp1
jsr dio_cts1541 ; get offset on second side of disk
lda tmp1 ; add second side base
clc
adc #<683
sta tmp1
lda tmp2
adc #>683
sta tmp2
jmp dio_ctsend
dio_cts1581:
; 1581 has 80 tracks, 40 sectors each secnum=track*40+sector
ldx #0
stx tmp3
stx tmp4
lda tmp1
beq _nomult
cmp #80
bcs _inv_data
; mul40 by Christian Groessler
sta tmp4
asl a
rol tmp3
asl a
rol tmp3 ; val * 4
adc tmp4
bcc L1
inc tmp3 ; val * 5
L1: asl a
rol tmp3 ; val * 10
asl a
rol tmp3
asl a
rol tmp3 ; val * 40 = AX
ldx tmp3
sta tmp3
stx tmp4
_nomult:
lda tmp2
clc
adc tmp3
sta tmp1
lda tmp4
adc #0
sta tmp2
jmp dio_ctsend
.rodata
sectab_1541_l:
.byte $00, $15, $2a, $3f, $54, $69, $7e, $93
.byte $a8, $bd, $d2, $e7, $fc, $11, $26, $3b
.byte $50, $65, $78, $8b, $9e, $b1, $c4, $d7
.byte $ea, $fc, $0e, $20, $32, $44, $56, $67
.byte $78, $89, $9a, $ab
sectab_1541_h:
.byte $00, $00, $00, $00, $00, $00, $00, $00
.byte $00, $00, $00, $00, $00, $01, $01, $01
.byte $01, $01, $01, $01, $01, $01, $01, $01
.byte $01, $01, $02, $02, $02, $02, $02, $02
.byte $02, $02, $02, $02