dont trash akku if possible, use VDC register when in 80column mode

2017-06-21 23:18:00 +02:00
parent 035621aa95
commit 49aad01bf1
2 changed files with 16 additions and 4 deletions
--- a/libsrc/c64/waitvblank.s
+++ b/libsrc/c64/waitvblank.s
@@ -5,9 +5,9 @@

 _waitvblank:
@l1:
-        lda     VIC_CTRL1
+        bit     VIC_CTRL1
        bpl     @l1
@l2:
-        lda     VIC_CTRL1
+        bit     VIC_CTRL1
        bmi     @l2
        rts