fix status register to match nestest

1 files changed, 8 insertions, 6 deletions

diff --git a/cpu.c b/cpu.c
index 6d8c599..66dbd4c 100644
--- a/cpu.c
+++ b/cpu.c
@@ -13,10 +13,10 @@
 #define STATUS_UPDATE_NEGATIVE(r)       \
         (regs.status.negative = ((r & (1 << 7)) != 0))
 #define STATUS_TO_INT()                 \
-        ((regs.status.carry << 7) | (regs.status.zero << 6) \
-            | (regs.status.interrupt_disable << 5) | (regs.status.decimal_mode << 4) \
-            | (regs.status.brk << 3) | (regs.status.unused << 2) \
-            | (regs.status.overflow << 1) | regs.status.negative)
+        (regs.status.carry | (regs.status.zero << 1) \
+            | (regs.status.interrupt_disable << 2) | (regs.status.decimal_mode << 3) \
+            | (regs.status.brk << 4) | (regs.status.unused << 5) \
+            | (regs.status.overflow << 6) | (regs.status.negative << 7))
 
 #define MEMORY_MIRROR(addr)     \
         if (addr < 0x2000)      \
@@ -766,7 +766,7 @@ tya(void)
 static void
 interpret(void)
 {
-        uint8_t opcode, did_memwrite, ret;
+        uint8_t opcode, did_memwrite, ret, status;
         uint16_t arg, mem, deref;
         uint32_t cycles_;
         enum addressing_mode mode;
@@ -775,6 +775,7 @@ interpret(void)
                 opcode = peek(regs.pc++);
                 cycles_ = cycles;
                 did_memwrite = 0;
+                status = STATUS_TO_INT();
 
                 printf("%04X  %02X", regs.pc - 1, opcode);
 
@@ -1908,7 +1909,7 @@ interpret(void)
                 }
 
                 printf("A:%02X X:%02X Y:%02X P:%02X SP:%02X CYC:%d\n",
-                    regs.a, regs.x, regs.y, STATUS_TO_INT(), regs.sp, cycles_);
+                    regs.a, regs.x, regs.y, status, regs.sp, cycles_);
         }
 loop_exit:
 }
@@ -1922,6 +1923,7 @@ cpu_init(void)
         regs.sp = 0xFD;
 
         //memset(&regs.status, 0, sizeof(regs.status));
+        regs.status.interrupt_disable = 1;
         regs.status.unused = 1;
 
         cycles += 7;