mirror of
https://github.com/cc65/cc65.git
synced 2024-11-19 06:31:31 +00:00
34 lines
745 B
ArmAsm
34 lines
745 B
ArmAsm
;
|
|
; 2018-04-20, Marco van den Heuvel
|
|
; 2018-04-26, Greg King
|
|
;
|
|
|
|
; unsigned char detect_c128 (void);
|
|
;
|
|
;/* Check for the presence of a C128 in C64 mode.
|
|
; *
|
|
; * Possible return values:
|
|
; * 0x00 : C128 in C64 mode not present
|
|
; * 0x01 : C128 in C64 mode present
|
|
; */
|
|
|
|
.export _detect_c128
|
|
|
|
.include "accelerator.inc"
|
|
|
|
_detect_c128:
|
|
ldx #>$0001
|
|
lda #<$0001
|
|
|
|
; Make sure the CPU is an 8502.
|
|
.byte $3A ; NOP on 8502, DEA on 65(S)C(E)02, 4510, and 65816
|
|
beq detect_end
|
|
|
|
; Make sure a C128 VIC-IIe is present.
|
|
ldy C128_VICIIE_CLK
|
|
cpy #$FF
|
|
bne detect_end
|
|
txa ; return zero when not VIC-IIe
|
|
detect_end:
|
|
rts
|