From 6800a11f605aaf72f9c283f3548a1cf10dc972da Mon Sep 17 00:00:00 2001
From: doom <61824552+JustDoom@users.noreply.github.com>
Date: Wed, 11 Dec 2024 13:41:10 +1000
Subject: [PATCH] Finish fixing compatability!

Was bored and clicked on the wikipedia link on the readme to chip8. I then looked at op codes and for some reason decided to switch theorder of setting the vF register and the x/y register. This then just solved half the issues. The rest were solved using similar methods
---
 src/emulator/Cpu.cpp | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/src/emulator/Cpu.cpp b/src/emulator/Cpu.cpp
index ec1f182..bac905e 100644
--- a/src/emulator/Cpu.cpp
+++ b/src/emulator/Cpu.cpp
@@ -145,43 +145,45 @@ void Cpu::runInstruction(const uint16_t opcode) {
                 case 0x4: {
                     const uint16_t sum = this->registers[x] + this->registers[y];
 
+                    this->registers[x] = sum & 0xFF;
+
                     if (sum > 0xFF) {
                         this->registers[0xF] = 1;
                     } else {
                         this->registers[0xF] = 0;
                     }
-
-                    this->registers[x] = sum & 0xFF;
+                    break;
                 }
-                break;
-                case 0x5:
-                    if (this->registers[x] >= this->registers[y]) {
-                        this->registers[0xF] = 1;
-                    } else {
-                        this->registers[0xF] = 0;
-                    }
+                case 0x5: {
+                    const uint8_t value = this->registers[x] >= this->registers[y] ? 1 : 0;
 
                     this->registers[x] -= this->registers[y];
+                    this->registers[0xF] = value;
                     break;
-                case 0x6:
-                    this->registers[0xF] = (this->registers[x] & 0x1);
-
+                }
+                case 0x6: {
+                    const uint8_t value = (this->registers[x] & 0x1);
                     this->registers[x] >>= 1;
+                    this->registers[0xF] = value;
                     break;
+                }
                 case 0x7:
 
+                    this->registers[x] = this->registers[y] - this->registers[x];
+
                     if (this->registers[y] >= this->registers[x]) {
                         this->registers[0xF] = 1;
                     } else {
                         this->registers[0xF] = 0;
                     }
 
-                    this->registers[x] = this->registers[y] - this->registers[x];
                     break;
-                case 0xE:
-                    this->registers[0xF] = (this->registers[x] & 0x80) >> 7;
+                case 0xE: {
+                    const uint8_t value = (this->registers[x] & 0x80) >> 7;
                     this->registers[x] <<= 1;
+                    this->registers[0xF] = value;
                     break;
+                }
                 default:
                     break;
             }
@@ -279,8 +281,8 @@ void Cpu::runInstruction(const uint16_t opcode) {
                     value /= 10;
 
                     this->memory[this->address] = value % 10;
+                    break;
                 }
-                break;
                 case 0x55:
                     for (uint8_t registerIndex = 0; registerIndex <= x; ++registerIndex) {
                         this->memory[this->address + registerIndex] = this->registers[registerIndex];