cc65/libsrc/apple2/curdevice.s

28 lines
497 B
ArmAsm

;
; Oliver Schmidt, 2012-10-21
;
; unsigned char getcurrentdevice (void);
;
.export _getcurrentdevice
.import __dos_type
.include "mli.inc"
_getcurrentdevice:
; Use unit number of most recent accessed device
lda DEVNUM
lsr
lsr
lsr
lsr
; Check for ProDOS 8
ldx __dos_type
bne :+
lda #$FF ; INVALID_DEVICE
: ldx #$00
rts