From 9a6188f821b11b69fff3d3a303dbfcce2e52e6f4 Mon Sep 17 00:00:00 2001
From: alekseiplusplus <alekseijeaves@protonmail.com>
Date: Thu, 27 Jul 2023 11:36:01 +1000
Subject: refactoring of src/cpu/

---
 src/cpu/6502.h | 107 +++++++++++++++++++--------------------------------------
 1 file changed, 35 insertions(+), 72 deletions(-)

(limited to 'src/cpu/6502.h')

diff --git a/src/cpu/6502.h b/src/cpu/6502.h
index 66526fd..c455e57 100644
--- a/src/cpu/6502.h
+++ b/src/cpu/6502.h
@@ -1,10 +1,10 @@
 //	6502.h
-//	Core elements of the 6502 CPU
+//	Main elements of the 6502 CPU
 
-typedef unsigned char
-	byte;
-typedef unsigned short
-	address;
+#ifndef CPU_6502_H
+#define CPU_6502_H
+
+#include"core.h"
 
 byte acc, X, Y, P, S = 0x00;
 address PC = 0x0000;
@@ -20,89 +20,52 @@ byte* ROM;
 #define flag_Z 0x02	// Zero
 #define flag_C 0x01	// Carry
 
-byte getFlag(byte flag) {
-	return ((P & flag) == flag) ? 1 : 0;
-}
-
-void setFlag(byte flag, int x) {
-	if (x == 1){
-		if ((P & flag) == 0x0)	P += flag;
-	}else if (x == 0){
-		if ((P & flag) == flag)	P -= flag;
-	}
-	else{
-		fprintf(stderr, "setFlag() passed arg neither 0 or 1");
-	}
-}
+byte getFlag(byte flag);
+// Get the value of a flag.
 
-void flagSet(byte flag){
-	P |= flag;
-}
+void setFlag(byte flag, int x);
+// Set a flag with some value.
 
-void flagClear(byte flag){
-	P &= ~flag;
-}
+void flagSet(byte flag);
+// Sets some flag.
 
+void flagClear(byte flag);
+// Clears some flag.
 
 //	Functions which perform reusable routines for finding if a specific flag should be set.
 
-void setFlagN(byte x){
-	if (x & flag_N == flag_N)
-		setFlag(flag_N, 1);
-	else
-		setFlag(flag_N, 0);
-}
+void setFlagN(byte x);
 
 //Perform prior to any changes
-void setFlagV(byte x, byte y){
-	if ((x & flag_N) == (y & flag_N)){
-		if (((x + y) & (flag_N ^ 0xFF)) > 0x7F) setFlag(flag_V, 1);
-		else setFlag(flag_V, 0);
-	}else{
-		if (((x - y) & (flag_N ^ 0xFF)) > 0x7F) setFlag(flag_V, 1);
-		else setFlag(flag_V, 0);
-	}
-}
-
-/*void setFlagB(){ //WORK ON
-	setFlag(flag_B, 1);
-}*/ //Dont really need since its dependent on the BRK insturction
-
-/*void setFlagD(){
-	setFlag(flag_D, 1);
-}*/
-
-/*void setFlagI(){ //WORK ON
-	setFlag(flag_Z, 1);
-}*/
-
-void setFlagZ(int x){
-	if (x == 0)
-		setFlag(flag_Z, 1);
-	else
-		setFlag(flag_Z, 0);
-}
+void setFlagV(byte x, byte y);
 
-//Only 6 instructions, 2 not including stack instructions, use the carry flag.
-// Need to look further into implementation details for this.
-/*void setFlagC(){
-	setFlag(flag_Z, 1);
-}*/
+//void setFlagB();
+//May not need since its dependent on the BRK insturction
 
+//void setFlagD();
+//Might not be necessary.
 
-//	Memory Manipulation
+//void setFlagI();
+//Need to work on.
 
-// Are to be defined by the system to handle special cases.
-
-byte getMemory(address x);
-void setMemory(address x, byte y);
+void setFlagZ(int x);
 
+//void setFlagC();
+//Only 6 instructions, 2 not including stack instructions, use the carry flag.
 
+// The following two may be better defined within apple.c
 
+//byte getMemory(address x);
+// Retrieve value from the computers address space.
+// It is important not to directly access the memory array because some value hold special meaning.
 
+//void setMemory(address x, byte y);
+// Set a piece of memory to some value.
 
+byte getStack();
+// Get top value of the stack.
 
+void setStack(byte z);
+// Set top value of the stack.
 
-#include"addressing.h"
-#include"instructions/definitions.h"
-#include"instructions/table.h"
\ No newline at end of file
+#endif
\ No newline at end of file
-- 
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