From 229509bc3b94fb481af65585ceb910db6d02bdec Mon Sep 17 00:00:00 2001
From: sigonasr2 <sigonasr2@gmail.com>
Date: Fri, 6 Jan 2023 00:26:15 -0600
Subject: [PATCH] Included original chipset functionality

Co-authored-by: sigonasr2 <sigonasr2@gmail.com>
---
 C++ProjectTemplate | Bin 585008 -> 585008 bytes
 main.cpp           |  30 +++++++++++++++++++++++++-----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/C++ProjectTemplate b/C++ProjectTemplate
index 04f0ff12b2a48f68a30dfbeebee7cd7b76fa55fc..cd0ddfca8daa2719b738c839363ed6ecbca0982f 100755
GIT binary patch
delta 517
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zdBVid&BEj{!=qQUVDri~2bsj)JwymS0<t|AFWCKmFqv_K*yd^LS1>c$O}5`Wm2uDH
ztD8$1gExC`(P!nAx`EKbx4C`i6)wie%`r#L3NY?&*1FoRb(L|u)>S6A-P|Rq#U=6i
z1<Cm-sng3RFk3P+FfdGCKY=;5ewy^(|3xx?|F;40J0Lcf{rkTGh@S#6m)zg~CP3V&
z43q<6CY8VcO@X)ph`*@){jaF;_rD5IJ_(4I0`UtV)|UVK{{s-OQuzCyTk-GzavkjW
zK2VNL<8S?cN1y@_w$OyoFg`xo2xu`(J`RZu69ds*IK+|FIO-Td4EjN&<>p#{|F`>0
WVg_OsAZ7((HXvr-?lXzwNfZFe0~1{U

delta 517
zcmdmROL+qjRWOT0#1tNB5<Z=>cJl@svu{@Nq0c0bZth`TyPWazWUJNbjM<YHt^UPZ
z@`Q<@n}x|^hDWbx#^#l44l;>7dx#La1!Q|LUa<TBU^3$dvCY%guV7}hnry#$D&vmH
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zOQu&(V78pTV*+zZ{XFTv|EpyF{_g|gZ$NA>`}cnb5WfXtA-TW*ZGd>9GEfePxm5oC
zw*}%3ApWEF_rIpb-~T#5`79t_3&bCQ*jWDW{~tiSN#XB*Va31y>vgc>=Ri3=jlcE(
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Uh*^M`6^Pk@n0>p?B#tLh0I6FO;s5{u

diff --git a/main.cpp b/main.cpp
index 13bf651..09f8295 100644
--- a/main.cpp
+++ b/main.cpp
@@ -57,6 +57,7 @@ public:
 	std::mt19937 gen; //Standard mersenne_twister_engine seeded with rd()
 	std::uniform_int_distribution<> distrib;
 	std::array<Key,16>keymap{X,K1,K2,K3,Q,W,E,A,S,D,Z,C,K4,R,F,V};
+	bool USE_ORIGINAL_CHIP8_SET=true;
 
 	std::string Display8(int number){
 		std::bitset<8>numb(number);
@@ -207,7 +208,14 @@ public:
 								reg[X]-=reg[Y];
 							}break;
 							case 0x6:{//Shift Right
-								//reg[X]=reg[Y];
+								if (USE_ORIGINAL_CHIP8_SET){
+									/*
+										In the CHIP-8 interpreter for the original COSMAC VIP, this instruction did the following: It put the value of VY into VX, and then shifted the value in VX 1 bit to the right (8XY6) or left (8XYE). VY was not affected, but the flag register VF would be set to the bit that was shifted out.
+
+										However, starting with CHIP-48 and SUPER-CHIP in the early 1990s, these instructions were changed so that they shifted VX in place, and ignored the Y completely.
+									*/
+									reg[X]=reg[Y];
+								}
 								reg[0xF]=reg[X]&0x1;
 								reg[X]>>=1;
 							}break;
@@ -220,12 +228,16 @@ public:
 							}break;
 							case 0xE:{//Shift Left
 								//std::cout<<"Y is: "<<(int)Y<<std::endl;
-								//reg[X]=reg[Y];
-								std::cout<<"Before left shift: "<<(int)reg[X]<<std::endl;
+								if (USE_ORIGINAL_CHIP8_SET){
+									/*
+										In the CHIP-8 interpreter for the original COSMAC VIP, this instruction did the following: It put the value of VY into VX, and then shifted the value in VX 1 bit to the right (8XY6) or left (8XYE). VY was not affected, but the flag register VF would be set to the bit that was shifted out.
+
+										However, starting with CHIP-48 and SUPER-CHIP in the early 1990s, these instructions were changed so that they shifted VX in place, and ignored the Y completely.
+									*/
+									reg[X]=reg[Y];
+								}
 								reg[0xF]=(reg[X]&0x80)>>7;
-								std::cout<<"Register F: "<<(int)reg[0xF]<<std::endl;
 								reg[X]<<=1;
-								std::cout<<"After Left shift: "<<(int)reg[X]<<std::endl;
 							}break;
 						}
 					}break;
@@ -321,11 +333,19 @@ public:
 								for (int i=0;i<=X;i++){
 									memory[index+i]=reg[i];
 								}
+								if (USE_ORIGINAL_CHIP8_SET){
+									/*The original CHIP-8 interpreter for the COSMAC VIP actually incremented the I register while it worked. Each time it stored or loaded one register, it incremented I. After the instruction was finished, I would be set to the new value I + X + 1.*/
+									index+=X+1;
+								}
 							}break;
 							case 0x65:{//Retrieves registers from V0 to VX in memory pointed by index.
 								for (int i=0;i<=X;i++){
 									reg[i]=memory[index+i];
 								}
+								if (USE_ORIGINAL_CHIP8_SET){
+									/*The original CHIP-8 interpreter for the COSMAC VIP actually incremented the I register while it worked. Each time it stored or loaded one register, it incremented I. After the instruction was finished, I would be set to the new value I + X + 1.*/
+									index+=X+1;
+								}
 							}break;
 						}
 					}break;