More instructions, misc system details

2 files changed, 165 insertions, 5 deletions

diff --git a/applesystem.h b/applesystem.h
index ea9b322..9b3dd1c 100644
--- a/applesystem.h
+++ b/applesystem.h
@@ -1,10 +1,13 @@
 typedef unsigned char byte;
-byte acc, X, Y, S, P = 0x00;
+typedef unsigned short address;
+byte acc, X, Y, P	= 0x00;
+unsigned short S	= 0x0000;
 byte Memory[4096]; // TO DO. Add expansion capability to memory.
 
 /*
 To Do.
 	+ Find variables better passed as pointers instead
+	+ Clean up this messy code
 */
 
 
@@ -32,10 +35,6 @@ void setFlag(byte flag, int x) { //OVERLOAD TO ACCEPT INT AS WELL
 	}
 }
 
-void toggleFlag(byte flag) {
-	P = ((P & flag) == flag) ? (P + flag) : (P - flag);
-}
-
 //	BCD
 
 byte toBCD(byte x){
diff --git a/instruction.h b/instruction.h
index 054e629..a5cc2b9 100644
--- a/instruction.h
+++ b/instruction.h
@@ -60,8 +60,41 @@ void fSBC(Addressing addr, int val){
 
 //Increment and Decrement Instructions
 
+void fINC(Addressing addr, int val){
+	Memory[x]++;
+	setFlagD(Memory[x]);
+	setFlagZ(Memory[x]);
+}
+
+void fINX(){
+	X++;
+	setFlagD(X);
+	setFlagZ(X);
+}
+
+void fINY(){
+	Y++;
+	setFlagD(Y);
+	setFlagZ(Y);
+}
+
+void fDEC(Addressing addr, int val){
+	Memory[x]--;
+	setFlagD(Memory[x]);
+	setFlagZ(Memory[x]);
+}
 
+void fDEX(){
+	X--;
+	setFlagD(X);
+	setFlagZ(X);
+}
 
+void fDEY(){
+	Y--;
+	setFlagD(Y);
+	setFlagZ(Y);
+}
 
 // Logical Instructions
 
@@ -85,12 +118,94 @@ void fEOR(Addressing addr, int val){
 
 // Jump, Branch, Compare, and Test Bits
 
+void fJMP(int val){
+	S = val;	
+}
+
+void fBCC(signed char val){
+	if (getFlag(flag_C) == 0) S += val;
+}
+
+void fBCS(signed char val){
+	if (getFlag(flag_C) == 1) S += val;
+}
+
+void fBEQ(signed char val){
+	if (getFlag(flag_Z) == 1) S += val;
+}
+
+void fBNE(signed char val){
+	if (getFlag(flag_Z) == 0) S += val;
+}
+
+void fBMI(signed char val){
+	if (getFlag(flag_N) == 1) S += val;
+}
+
+void fBPL(signed char val){
+	if (getFlag(flag_N) == 0) S += val;
+}
+
+void fBVS(signed char val){
+	if (getFlag(flag_V) == 1) S += val;
+}
+
+void fBVC(signed char val){
+	if (getFlag(flag_V) == 0) S += val;
+}
+
+void fCMP(address val){
+	if (acc < Memory[val]){
+		setFlag(flag_N, 1); setFlag(flag_Z, 0); setFlag(flag_C, 0);
+	}if (acc == Memory[val]){
+		setFlag(flag_N, 0); setFlag(flag_Z, 1); setFlag(flag_C, 0);
+	}if (acc > Memory[val]){
+		setFlag(flag_N, 0); setFlag(flag_Z, 0); setFlag(flag_C, 1);
+	}
+}
 
+void fCPX(address val){
+	if (X < Memory[val]){
+		setFlag(flag_N, 1); setFlag(flag_Z, 0); setFlag(flag_C, 0);
+	}if (X == Memory[val]){
+		setFlag(flag_N, 0); setFlag(flag_Z, 1); setFlag(flag_C, 0);
+	}if (X > Memory[val]){
+		setFlag(flag_N, 0); setFlag(flag_Z, 0); setFlag(flag_C, 1);
+	}
+}
 
+void fCPY(address val){
+	if (Y < Memory[val]){
+		setFlag(flag_N, 1); setFlag(flag_Z, 0); setFlag(flag_C, 0);
+	}if (Y == Memory[val]){
+		setFlag(flag_N, 0); setFlag(flag_Z, 1); setFlag(flag_C, 0);
+	}if (Y > Memory[val]){
+		setFlag(flag_N, 0); setFlag(flag_Z, 0); setFlag(flag_C, 1);
+	}
+}
 
+void fBIT(address val){
+	setFlag(flag_N, (Memory[val] & flag_N));
+	setFlag(flag_V, (Memory[val] & flag_V));
+	if (((Memory[val] & flag_N) & (Memory[val] & flag_V)) == 0) {
+		setFlag(flag_Z, 1);
+	} else {
+		setFlag(flag_Z, 0);
+	}
+}
 
 // Shift and Rotate Instructions
 
+/*   ASL  - Accumulator Shift Left
+   LSR  - Logical Shift Right
+   ROL  - ROtate Left
+   ROR  - ROtate Right
+   
+    Z is set if the result it zero.  N is set if bit 7 is 1.  It is 
+    always reset on LSR.  Remember that ASL A is equal to multiplying by 
+    two and that LSR is equal to dividing by two.*/
+
+
 void fASL(Addressing addr, int val){
 	setFlag(flag_C, (val & 0x80));
 	acc = (val << 1);
@@ -98,9 +213,55 @@ void fASL(Addressing addr, int val){
 	setFlagZ(acc);
 }
 
+/*   Use these instructions to move things around in the accumulator or 
+   memory.  The net effects are (where C is the carry flag):
+
+   
+           +-+-+-+-+-+-+-+-+ 
+      C <- |7|6|5|4|3|2|1|0| <- 0    ASL
+           +-+-+-+-+-+-+-+-+
+           
+           +-+-+-+-+-+-+-+-+ 
+      0 -> |7|6|5|4|3|2|1|0| -> C    LSR
+           +-+-+-+-+-+-+-+-+
+
+           +-+-+-+-+-+-+-+-+ 
+      C <- |7|6|5|4|3|2|1|0| <- C    ROL
+           +-+-+-+-+-+-+-+-+
+
+           +-+-+-+-+-+-+-+-+ 
+      C -> |7|6|5|4|3|2|1|0| -> C    ROR
+           +-+-+-+-+-+-+-+-+
+*/
+
 
 // Transfer Instructions
 
+void fTAX(){
+	X = acc;
+	setFlagN(X);
+	setFlagZ(X);
+}
+
+void fTAY(){
+	Y = acc;
+	setFlagN(Y);
+	setFlagZ(Y);
+}
+
+void fTXA(){
+	acc = X;
+	setFlagN(acc);
+	setFlagZ(acc);
+}
+
+void fTYA(){
+	acc = Y;
+	setFlagN(acc);
+	setFlagZ(acc);
+}
+
+
 // Stack Instructions
 
 // Subroutine Instructions