Add basic support for ORIC Atmos

git-svn-id: svn://svn.cc65.org/cc65/trunk@2046 b7a2c559-68d2-44c3-8de9-860c34a00d81
2003-04-13 22:12:09 +00:00
parent d48f341bba
commit 9f547a5a4d
21 changed files with 1001 additions and 5 deletions
--- a/libsrc/atmos/clock.s
+++ b/libsrc/atmos/clock.s
@@ -0,0 +1,36 @@
+;
+; Ullrich von Bassewitz, 2003-04-13
+;
+; clock_t clock (void);
+;
+
+	.export		_clock
+        .import         negax
+	.importzp	sreg
+
+	.include	"atmos.inc"
+
+
+.proc	_clock
+
+; Clear the timer high 16 bits
+
+        ldy     #$00
+        sty     sreg
+        sty     sreg+1
+
+; Read the timer
+
+        sei                     ; Disable interrupts
+        lda     TIMER3
+        ldx     TIMER3+1
+        cli                     ; Reenable interrupts
+
+
+; Since the timer is counting downwards, return the negated value
+
+        jmp     negax
+
+.endproc
+
+