mirror of
https://github.com/cc65/cc65.git
synced 2024-11-04 17:04:58 +00:00
79 lines
2.0 KiB
ArmAsm
79 lines
2.0 KiB
ArmAsm
;
|
|
; Oliver Schmidt, 2012-09-04
|
|
; Christian Groessler, 2017-12-28
|
|
;
|
|
; unsigned char getfirstdevice (void);
|
|
; unsigned char __fastcall__ getnextdevice (unsigned char device);
|
|
;
|
|
|
|
.include "atari.inc"
|
|
.export _getfirstdevice
|
|
.export _getnextdevice
|
|
|
|
MAX_DIO_DEVICES = 8
|
|
|
|
;------------------------------------------------------------------------------
|
|
; _getfirstdevice
|
|
|
|
_getfirstdevice:
|
|
lda #$FF
|
|
; Fall through
|
|
|
|
;------------------------------------------------------------------------------
|
|
; _getnextdevice
|
|
|
|
_getnextdevice:
|
|
tax
|
|
next: inx
|
|
cpx #MAX_DIO_DEVICES
|
|
beq none
|
|
|
|
jsr check_device
|
|
bmi next
|
|
|
|
done: txa
|
|
ldx #$00
|
|
rts
|
|
|
|
none: ldx #255 ; INVALID_DEVICE (see include/device.h)
|
|
bne done ; jump always
|
|
|
|
;------------------------------------------------------------------------------
|
|
; check_device - checks if a disk device is present
|
|
; input: X - device id (0 = D1, 1 = D2, ...)
|
|
; output: NF - 0/1 for detected/not detected
|
|
; X register preserved
|
|
|
|
check_device:
|
|
txa
|
|
pha
|
|
lda #SIO_STAT
|
|
sta DCOMND ; set command into DCB
|
|
lda #%01000000 ; direction value, "receive data"
|
|
sta DSTATS ; set data flow directon
|
|
lda #15
|
|
sta DTIMLO ; value got from DOS source
|
|
lda #4
|
|
sta DAUX1 ; set sector # (dummy: 4)
|
|
sta DBYTLO ; # of bytes to transfer
|
|
lda #0
|
|
sta DAUX2
|
|
sta DBYTHI
|
|
lda #>DVSTAT
|
|
sta DBUFHI
|
|
lda #<DVSTAT
|
|
sta DBUFLO ; set buffer address into DCB
|
|
lda #DISKID ; SIO bus ID of diskette drive
|
|
sta DDEVIC
|
|
inx
|
|
stx DUNIT ; unit number (1-based)
|
|
|
|
jsr SIOV ; execute SIO command
|
|
|
|
pla
|
|
tax
|
|
lda DSTATS
|
|
rts
|
|
|
|
.end
|