diff --git a/src/main/fragment/cache/fragment-cache-wdc65c02.asm b/src/main/fragment/cache/fragment-cache-wdc65c02.asm
index ad65f1d49..723d8e70a 100644
--- a/src/main/fragment/cache/fragment-cache-wdc65c02.asm
+++ b/src/main/fragment/cache/fragment-cache-wdc65c02.asm
@@ -4704,3 +4704,12 @@ tay
 lda {c1}
 ora {c2},y
 tay
+//FRAGMENT vwuz1_lt_vwuc1_then_la1
+lda {z1}+1
+cmp #>{c1}
+bcc {la1}
+bne !+
+lda {z1}
+cmp #<{c1}
+bcc {la1}
+!:
diff --git a/src/main/kc/lib/bitmap-draw-cx16.c b/src/main/kc/lib/bitmap-draw-cx16.c
index d14fab201..171624611 100644
--- a/src/main/kc/lib/bitmap-draw-cx16.c
+++ b/src/main/kc/lib/bitmap-draw-cx16.c
@@ -26,14 +26,7 @@ void bitmap_init(word bitmap_address) {
 
 // Clear all graphics on the bitmap
 void bitmap_clear() {
-    word bitmap_address = bitmap;
-    for( word y: 0..600 ) {
-        for( word x: 0..40 ) {
-            vera_vram_bank_offset(0,(word)bitmap_address,VERA_INC_0);
-            *VERA_DATA0 = 0;
-            bitmap_address++;
-        }
-    }
+    memset_vram(0,bitmap,0,80*60*8);
 }
 
 void bitmap_plot(word x, word y) {