mirror of
https://github.com/cc65/cc65.git
synced 2024-11-17 09:07:32 +00:00
57 lines
1.6 KiB
ArmAsm
57 lines
1.6 KiB
ArmAsm
;
|
|
; Marco van den Heuvel, 2018-04-30
|
|
;
|
|
|
|
; unsigned char __fastcall__ set_turbomaster_speed (unsigned char speed);
|
|
;
|
|
;/* Set the speed of the Turbo Master cartridge, using SPEED_SLOW will switch to
|
|
; * 1 Mhz mode, SPEED_4X or SPEED_FAST will switch to 4 Mhz mode.
|
|
; *
|
|
; * Note that any value higher or equal to SPEED_4X will switch to 4 Mhz mode,
|
|
; * any value lower than SPEED_4X will switch to 1 Mhz mode.
|
|
; *
|
|
; * This function will return the actual speed the CPU is at after trying
|
|
; * to set the requested speed, if the speed is different it might indicate
|
|
; * that the hardware switch has locked the speed.
|
|
; *
|
|
; * This function does not check for the presence of a Turbo Master cartridge,
|
|
; * make sure you use 'detect_turbomaster();' before using.
|
|
; */
|
|
|
|
; unsigned char get_turbomaster_speed (void);
|
|
;
|
|
;/* Get the speed of the Turbo Master cartridge.
|
|
; *
|
|
; * Possible return values:
|
|
; * SPEED_SLOW : 1 Mhz mode
|
|
; * SPEED_4X : 4 Mhz mode
|
|
; *
|
|
; * This function does not check for the presence of a Turbo Master cartridge,
|
|
; * make sure you use 'detect_turbomaster();' before using.
|
|
; */
|
|
|
|
.export _set_turbomaster_speed
|
|
.export _get_turbomaster_speed
|
|
|
|
.include "accelerator.inc"
|
|
|
|
_set_turbomaster_speed:
|
|
tay
|
|
lda TURBOMASTER_SPEED_REG
|
|
asl
|
|
cpy #SPEED_4X
|
|
ror
|
|
store_speed:
|
|
sta TURBOMASTER_SPEED_REG
|
|
|
|
_get_turbomaster_speed:
|
|
ldx #$00
|
|
lda TURBOMASTER_SPEED_REG
|
|
and #$80
|
|
beq is_slow_speed
|
|
is_high_speed:
|
|
lda #SPEED_4X
|
|
is_slow_speed:
|
|
rts
|
|
|