Split clock file to components

2022-03-22 21:29:06 +02:00
parent 218c98d4d5
commit cf8c7ee28d
2 changed files with 35 additions and 21 deletions
--- a/libsrc/atari7800/clocks_per_sec.s
+++ b/libsrc/atari7800/clocks_per_sec.s
@@ -0,0 +1,34 @@
+;
+; 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
+