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cc65/libsrc/atari/clock.s
cpg d10a647baf both routines fixed (fix by Piotr Fusik)
git-svn-id: svn://svn.cc65.org/cc65/trunk@1098 b7a2c559-68d2-44c3-8de9-860c34a00d81
2001-11-05 23:52:19 +00:00

44 lines
711 B
ArmAsm

;
; Piotr Fusik, 04.11.2001
; originally by Ullrich von Bassewitz and Sidney Cadot
;
; clock_t clock (void);
; unsigned _clocks_per_sec (void);
;
.export _clock, __clocks_per_sec
.importzp sreg
.include "atari.inc"
.proc _clock
ldx #5 ; Synchronize with Antic, so the interrupt won't change RTCLOK
stx WSYNC ; while we're reading it. The synchronization is done same as
@L1: dex ; in SETVBLV function in Atari OS.
bne @L1
stx sreg+1 ; Byte 3 is always zero
lda RTCLOK+2
ldx RTCLOK+1
ldy RTCLOK
sty sreg
rts
.endproc
.proc __clocks_per_sec
lda PAL ; use hw register, PALNTS is only supported on XL/XE ROM
and #$0e
bne @NTSC
tax
lda #50
rts
@NTSC: ldx #0
lda #60
rts
.endproc