From 9dd876b62299a3bbc4384ba75938eab601580176 Mon Sep 17 00:00:00 2001
From: Denis-Cosmin NUTIU <dnutiu@bitdefender.com>
Date: Sat, 7 Dec 2024 22:13:58 +0200
Subject: [PATCH] fix shift

---
 src/emulator.rs | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/emulator.rs b/src/emulator.rs
index 0c2fa58..760b679 100644
--- a/src/emulator.rs
+++ b/src/emulator.rs
@@ -286,14 +286,12 @@ where
             }
             ProcessorInstruction::ShiftLeft(vx, vy) => {
                 trace!("ShiftLeft VX={vx:04x} VY={vy:04x}");
-                // Original chip8 behavior
-                self.registers[0xF] = (self.registers[vx as usize] & 0x10) >> 4;
+                self.registers[0xF] = (self.registers[vx as usize] >> 7) & 1;
                 self.registers[vx as usize] <<= 1;
             }
             ProcessorInstruction::ShiftRight(vx, vy) => {
                 trace!("ShiftRight VX={vx:04x} VY={vy:04x}");
-                // Original chip8 behavior
-                self.registers[0xF] = self.registers[vx as usize] & 0x01;
+                self.registers[0xF] = self.registers[vx as usize] & 0x1;
                 self.registers[vx as usize] >>= 1;
             }
             ProcessorInstruction::JumpWithOffset(address) => {