fixes ADC bug introduced in last commit

2012-03-21 10:17:40 -04:00 · 2012-03-21 10:17:40 -04:00 · ea1e8f192e
parent e932b9b7ac
commit ea1e8f192e
1 changed files with 2 additions and 1 deletions
--- a/src/d6502/cpu.d
+++ b/src/d6502/cpu.d
@ -358,7 +358,8 @@ class Cpu : CpuBase
            al = ((al + 0x06) & 0x0F) + 0x10;
        a = (a & 0xF0) + (val & 0xF0) + al;

-        flag.negative_ = flag.zero_ = cast(ubyte)a;
+        flag.negative_ = cast(ubyte)a;
+        flag.zero_ = cast(ubyte)(accumulator + val + flag.carry);
        flag.overflow =
            (!((accumulator ^ val) & 0x80)) && ((val ^ a) & 0x80);