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cc65/libsrc/atari7800/clocks_per_sec.s
2022-07-21 03:20:44 +02:00

35 lines
726 B
ArmAsm

;
; 2022-03-15, Karri Kaksonen
;
; clock_t _clocks_per_sec (void);
;
.export __clocks_per_sec
.import sreg: zp
.import _paldetected
.include "atari7800.inc"
.macpack generic
.code
;-----------------------------------------------------------------------------
; Return the number of clock ticks in one second.
;
.proc __clocks_per_sec
lda #0
tax
sta sreg ; return 32 bits
sta sreg+1
lda _paldetected
bne pal
lda #60 ; NTSC - 60Hz
rts
pal:
lda #50 ; PAL - 50Hz
rts
.endproc