mirror of
https://github.com/cc65/cc65.git
synced 2024-11-19 06:31:31 +00:00
47 lines
868 B
ArmAsm
47 lines
868 B
ArmAsm
|
; ***
|
||
|
|
; CC65 Lynx Library
|
||
|
|
;
|
||
|
|
; Originally by Bastian Schick, BLL kit mikey.mac
|
||
|
|
; http://www.geocities.com/SiliconValley/Byte/4242/lynx/
|
||
|
|
;
|
||
|
|
; Ported to cc65 (http://www.cc65.org) by
|
||
|
|
; Shawn Jefferson, June 2004
|
||
|
|
;
|
||
|
|
; Ullrich von Bassewitz, 2004-10-09, small changes.
|
||
|
|
;
|
||
|
|
; void __fastcall__ lynx_change_framerate (unsigned char rate);
|
||
|
|
; /* Change the framerate, in Hz. Recognized values are 50, 60 and 75. */
|
||
|
|
;
|
||
|
|
|
||
|
|
.include "lynx.inc"
|
||
|
|
.export _lynx_change_framerate
|
||
|
|
|
||
|
|
.code
|
||
|
|
|
||
|
|
|
||
|
|
_lynx_change_framerate:
|
||
|
|
cmp #75
|
||
|
|
beq set_75
|
||
|
|
cmp #60
|
||
|
|
beq set_60
|
||
|
|
cmp #50
|
||
|
|
bne exit
|
||
|
|
|
||
|
|
set_50: lda #$bd
|
||
|
|
ldx #$31
|
||
|
|
bra doit
|
||
|
|
|
||
|
|
set_60: lda #$9e
|
||
|
|
ldx #$29
|
||
|
|
bra doit
|
||
|
|
|
||
|
|
set_75: lda #$7e
|
||
|
|
ldx #$20
|
||
|
|
|
||
|
|
doit: sta HTIMBKUP
|
||
|
|
stx PBKUP
|
||
|
|
|
||
|
|
exit: rts
|
||
|
|
|
||
|
|
|