From d34c93a464b09109d2226fefb3bb6cf701049905 Mon Sep 17 00:00:00 2001
From: Marco van den Heuvel <blackystardust68@yahoo.com>
Date: Tue, 20 Mar 2018 14:05:55 -0700
Subject: [PATCH] Set X register to 0 so that 16bit promotion works as
 expected.

---
 libsrc/c128/isfast.s | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libsrc/c128/isfast.s b/libsrc/c128/isfast.s
index 01b597371..d40e2c7e9 100644
--- a/libsrc/c128/isfast.s
+++ b/libsrc/c128/isfast.s
@@ -14,6 +14,7 @@
 
         lda     VIC_CLK_128
         and     #$01
+        ldx     #$00
         rts
 
 .endproc