implement tay, txa, tya

1 files changed, 12 insertions, 3 deletions

diff --git a/cpu.c b/cpu.c
index acb4efb..d754c15 100644
--- a/cpu.c
+++ b/cpu.c
@@ -588,7 +588,10 @@ tax(void)
 static void
 tay(uint8_t arg)
 {
-/* TODO: complete this */
+        regs.y = regs.a;
+
+        STATUS_UPDATE_ZERO(regs.y);
+        STATUS_UPDATE_NEGATIVE(regs.y);
 }
 
 static void
@@ -600,7 +603,10 @@ tsx(uint8_t arg)
 static void
 txa(uint8_t arg)
 {
-/* TODO: complete this */
+        regs.a = regs.x;
+
+        STATUS_UPDATE_ZERO(regs.a);
+        STATUS_UPDATE_NEGATIVE(regs.a);
 }
 
 static void
@@ -612,7 +618,10 @@ txs(uint8_t arg)
 static void
 tya(uint8_t arg)
 {
-/* TODO: complete this */
+        regs.a = regs.y;
+
+        STATUS_UPDATE_ZERO(regs.a);
+        STATUS_UPDATE_NEGATIVE(regs.a);
 }
 
 static void