From: mrdudz <mrdudz@users.noreply.github.com>
Date: Wed, 21 Jun 2017 21:18:00 +0000 (+0200)
Subject: dont trash akku if possible, use VDC register when in 80column mode
X-Git-Tag: V2.17~116^2~9
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=49aad01bf105fb731270a964c6130c3f52165c0d;p=cc65

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

diff --git a/libsrc/c128/waitvblank.s b/libsrc/c128/waitvblank.s
index 54699286c..e0a469d0e 100644
--- a/libsrc/c128/waitvblank.s
+++ b/libsrc/c128/waitvblank.s
@@ -4,10 +4,22 @@
         .include        "c128.inc"
 
 _waitvblank:
+
+        lda     MODE
+        bmi     @c80
+
 @l1:
-        lda     VIC_CTRL1
+        bit     VIC_CTRL1
         bpl     @l1
 @l2:
-        lda     VIC_CTRL1
+        bit     VIC_CTRL1
         bmi     @l2
         rts
+
+@c80:
+        ;FIXME: do we have to switch banks?
+@l3:
+        lda     VDC_INDEX
+        and     #$20
+        beq     @l3
+        rts
diff --git a/libsrc/c64/waitvblank.s b/libsrc/c64/waitvblank.s
index 606f41681..dd9087841 100644
--- 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