Merge pull request #17 from maikf/rtc

[c128-kasse] / src / bcd2dec.s

diff --git a/src/bcd2dec.s b/src/bcd2dec.s
new file mode 100644 (file)
index 0000000..3056693
--- /dev/null
+++ b/src/bcd2dec.s
@@ -0,0 +1,23 @@
+
+        .export   _bcd2dec
+        .importzp tmp1,tmp2
+
+.code
+
+;; Copied from [cc65]/libsrc/c128/systime.s
+
+.proc   _bcd2dec
+        tax
+        and     #%00001111
+        sta     tmp1
+        txa
+        and     #%11110000      ; *16
+        lsr                     ; *8
+        sta     tmp2
+        lsr
+        lsr                     ; *2
+        adc     tmp2            ; = *10
+        adc     tmp1
+        ldx     #0
+        rts
+.endproc