Makefile

@@ -1,25 +1,17 @@
-.ONESHELL:
-
-CC=gcc
 CFLAGS=-lcsfml-window -lcsfml-system -lcsfml-graphics
 PREFIX=$(HOME)/.local
+CACHE=$(shell if [ "$$XDG_CACHE_HOME" ]; then echo "$$XDG_CACHE_HOME"; else echo "$$HOME"/.cache; fi)
 
 all: ls7emulator
 
 clean:
-	rm -rf bin/ls7emulator bin/
+	rm -f ls7emulator $(CACHE)/ls7emulator
 
-ls7emulator:
+ls7emulator: ls7emulator.c ls7emulator.h config.h
-	cd src
 	$(CC) ls7emulator.c -o ls7emulator $(CFLAGS)
-	
-	rm ../bin -rf
-	mkdir ../bin
-	cd ../bin
-	mv ../src/ls7emulator ./
 	strip ls7emulator
 
 install: ls7emulator
 	mkdir -p $(PREFIX)/bin
-	install bin/ls7emulator $(PREFIX)/bin/ls7emulator
+	install ./ls7emulator $(PREFIX)/bin/ls7emulator
-	cp bin/ls7emulator /usr/bin/ls7emulator
+	cp ./ls7emulator /usr/bin/ls7emulator

src/cpu.c

@@ -12,6 +12,14 @@ extern uint8_t read6502(uint16_t address);
 extern void write6502(uint16_t address, uint8_t value);
 
 //6502 defines
+#define UNDOCUMENTED //when this is defined, undocumented opcodes are handled.
+                     //otherwise, they're simply treated as NOPs.
+
+//#define NES_CPU      //when this is defined, the binary-coded decimal (BCD)
+                     //status flag is not honored by ADC and SBC. the 2A03
+                     //CPU in the Nintendo Entertainment System does not
+                     //support BCD operation.
+
 #define FLAG_CARRY     0x01
 #define FLAG_ZERO      0x02
 #define FLAG_INTERRUPT 0x04
@@ -69,17 +77,10 @@ uint8_t sp, a, x, y, status = FLAG_CONSTANT;
 
 
 //helper variables
-uint32_t clockticks6502 = 0;
+uint64_t instructions = 0; //keep track of total instructions executed
-uint32_t clockgoal6502 = 0;
+uint32_t clockticks6502 = 0, clockgoal6502 = 0;
-
+uint16_t oldpc, ea, reladdr, value, result;
-uint16_t oldpc;
+uint8_t opcode, oldstatus;
-uint16_t ea;
-uint16_t reladdr;
-uint16_t value;
-uint16_t result;
-
-uint8_t opcode;
-uint8_t oldstatus;
 
 //a few general functions used by various other functions
 void push16(uint16_t pushval) {
@@ -156,7 +157,7 @@ static void absx() { //absolute,X
     startpage = ea & 0xFF00;
     ea += (uint16_t)x;
 
-    if (startpage != (ea & 0xFF00)) { //one cycle penalty for page-crossing on some opcodes
+    if (startpage != (ea & 0xFF00)) { //one cycle penlty for page-crossing on some opcodes
         penaltyaddr = 1;
     }
 
@@ -225,6 +226,22 @@ static void adc() {
     overflowcalc(result, a, value);
     signcalc(result);
 
+    #ifndef NES_CPU
+    if (status & FLAG_DECIMAL) {
+        clearcarry();
+
+        if ((a & 0x0F) > 0x09) {
+            a += 0x06;
+        }
+        if ((a & 0xF0) > 0x90) {
+            a += 0x60;
+            setcarry();
+        }
+
+        clockticks6502++;
+    }
+    #endif
+
     saveaccum(result);
 }
 
@@ -555,7 +572,6 @@ static void ror() {
 
     if (value & 1) setcarry();
         else clearcarry();
-    
     zerocalc(result);
     signcalc(result);
 
@@ -583,6 +599,23 @@ static void sbc() {
     overflowcalc(result, a, value);
     signcalc(result);
 
+    #ifndef NES_CPU
+    if (status & FLAG_DECIMAL) {
+        clearcarry();
+
+        a -= 0x66;
+        if ((a & 0x0F) > 0x09) {
+            a += 0x06;
+        }
+        if ((a & 0xF0) > 0x90) {
+            a += 0x60;
+            setcarry();
+        }
+
+        clockticks6502++;
+    }
+    #endif
+
     saveaccum(result);
 }
 
@@ -649,6 +682,67 @@ static void tya() {
     signcalc(a);
 }
 
+//undocumented instructions
+#ifdef UNDOCUMENTED
+    static void lax() {
+        lda();
+        ldx();
+    }
+
+    static void sax() {
+        sta();
+        stx();
+        putvalue(a & x);
+        if (penaltyop && penaltyaddr) clockticks6502--;
+    }
+
+    static void dcp() {
+        dec();
+        cmp();
+        if (penaltyop && penaltyaddr) clockticks6502--;
+    }
+
+    static void isb() {
+        inc();
+        sbc();
+        if (penaltyop && penaltyaddr) clockticks6502--;
+    }
+
+    static void slo() {
+        asl();
+        ora();
+        if (penaltyop && penaltyaddr) clockticks6502--;
+    }
+
+    static void rla() {
+        rol();
+        and();
+        if (penaltyop && penaltyaddr) clockticks6502--;
+    }
+
+    static void sre() {
+        lsr();
+        eor();
+        if (penaltyop && penaltyaddr) clockticks6502--;
+    }
+
+    static void rra() {
+        ror();
+        adc();
+        if (penaltyop && penaltyaddr) clockticks6502--;
+    }
+#else
+    #define lax nop
+    #define sax nop
+    #define dcp nop
+    #define isb nop
+    #define slo nop
+    #define rla nop
+    #define sre nop
+    #define rra nop
+#endif
+
+
 static void (*addrtable[256])() = {
 /*        |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  A  |  B  |  C  |  D  |  E  |  F  |     */
 /* 0 */     imp, indx,  imp, indx,   zp,   zp,   zp,   zp,  imp,  imm,  acc,  imm, abso, abso, abso, abso, /* 0 */
@@ -671,22 +765,22 @@ static void (*addrtable[256])() = {
 
 static void (*optable[256])() = {
 /*        |  0  |  1  |  2  |  3  |  4  |  5  |  6  |  7  |  8  |  9  |  A  |  B  |  C  |  D  |  E  |  F  |      */
-/* 0 */      brk,  ora,  nop,  nop,  nop,  ora,  asl,  nop,  php,  ora,  asl,  nop,  nop,  ora,  asl,  nop, /* 0 */
+/* 0 */      brk,  ora,  nop,  slo,  nop,  ora,  asl,  slo,  php,  ora,  asl,  nop,  nop,  ora,  asl,  slo, /* 0 */
-/* 1 */      bpl,  ora,  nop,  nop,  nop,  ora,  asl,  nop,  clc,  ora,  nop,  nop,  nop,  ora,  asl,  nop, /* 1 */
+/* 1 */      bpl,  ora,  nop,  slo,  nop,  ora,  asl,  slo,  clc,  ora,  nop,  slo,  nop,  ora,  asl,  slo, /* 1 */
-/* 2 */      jsr,  and,  nop,  nop,  bit,  and,  rol,  nop,  plp,  and,  rol,  nop,  bit,  and,  rol,  nop, /* 2 */
+/* 2 */      jsr,  and,  nop,  rla,  bit,  and,  rol,  rla,  plp,  and,  rol,  nop,  bit,  and,  rol,  rla, /* 2 */
-/* 3 */      bmi,  and,  nop,  nop,  nop,  and,  rol,  nop,  sec,  and,  nop,  nop,  nop,  and,  rol,  nop, /* 3 */
+/* 3 */      bmi,  and,  nop,  rla,  nop,  and,  rol,  rla,  sec,  and,  nop,  rla,  nop,  and,  rol,  rla, /* 3 */
-/* 4 */      rti,  eor,  nop,  nop,  nop,  eor,  lsr,  nop,  pha,  eor,  lsr,  nop,  jmp,  eor,  lsr,  nop, /* 4 */
+/* 4 */      rti,  eor,  nop,  sre,  nop,  eor,  lsr,  sre,  pha,  eor,  lsr,  nop,  jmp,  eor,  lsr,  sre, /* 4 */
-/* 5 */      bvc,  eor,  nop,  nop,  nop,  eor,  lsr,  nop,  cli,  eor,  nop,  nop,  nop,  eor,  lsr,  nop, /* 5 */
+/* 5 */      bvc,  eor,  nop,  sre,  nop,  eor,  lsr,  sre,  cli,  eor,  nop,  sre,  nop,  eor,  lsr,  sre, /* 5 */
-/* 6 */      rts,  adc,  nop,  nop,  nop,  adc,  ror,  nop,  pla,  adc,  ror,  nop,  jmp,  adc,  ror,  nop, /* 6 */
+/* 6 */      rts,  adc,  nop,  rra,  nop,  adc,  ror,  rra,  pla,  adc,  ror,  nop,  jmp,  adc,  ror,  rra, /* 6 */
-/* 7 */      bvs,  adc,  nop,  nop,  nop,  adc,  ror,  nop,  sei,  adc,  nop,  nop,  nop,  adc,  ror,  nop, /* 7 */
+/* 7 */      bvs,  adc,  nop,  rra,  nop,  adc,  ror,  rra,  sei,  adc,  nop,  rra,  nop,  adc,  ror,  rra, /* 7 */
-/* 8 */      nop,  sta,  nop,  nop,  sty,  sta,  stx,  nop,  dey,  nop,  txa,  nop,  sty,  sta,  stx,  nop, /* 8 */
+/* 8 */      nop,  sta,  nop,  sax,  sty,  sta,  stx,  sax,  dey,  nop,  txa,  nop,  sty,  sta,  stx,  sax, /* 8 */
-/* 9 */      bcc,  sta,  nop,  nop,  sty,  sta,  stx,  nop,  tya,  sta,  txs,  nop,  nop,  sta,  nop,  nop, /* 9 */
+/* 9 */      bcc,  sta,  nop,  nop,  sty,  sta,  stx,  sax,  tya,  sta,  txs,  nop,  nop,  sta,  nop,  nop, /* 9 */
-/* A */      ldy,  lda,  ldx,  nop,  ldy,  lda,  ldx,  nop,  tay,  lda,  tax,  nop,  ldy,  lda,  ldx,  nop, /* A */
+/* A */      ldy,  lda,  ldx,  lax,  ldy,  lda,  ldx,  lax,  tay,  lda,  tax,  nop,  ldy,  lda,  ldx,  lax, /* A */
-/* B */      bcs,  lda,  nop,  nop,  ldy,  lda,  ldx,  nop,  clv,  lda,  tsx,  nop,  ldy,  lda,  ldx,  nop, /* B */
+/* B */      bcs,  lda,  nop,  lax,  ldy,  lda,  ldx,  lax,  clv,  lda,  tsx,  lax,  ldy,  lda,  ldx,  lax, /* B */
-/* C */      cpy,  cmp,  nop,  nop,  cpy,  cmp,  dec,  nop,  iny,  cmp,  dex,  nop,  cpy,  cmp,  dec,  nop, /* C */
+/* C */      cpy,  cmp,  nop,  dcp,  cpy,  cmp,  dec,  dcp,  iny,  cmp,  dex,  nop,  cpy,  cmp,  dec,  dcp, /* C */
-/* D */      bne,  cmp,  nop,  nop,  nop,  cmp,  dec,  nop,  cld,  cmp,  nop,  nop,  nop,  cmp,  dec,  nop, /* D */
+/* D */      bne,  cmp,  nop,  dcp,  nop,  cmp,  dec,  dcp,  cld,  cmp,  nop,  dcp,  nop,  cmp,  dec,  dcp, /* D */
-/* E */      cpx,  sbc,  nop,  nop,  cpx,  sbc,  inc,  nop,  inx,  sbc,  nop,  sbc,  cpx,  sbc,  inc,  nop, /* E */
+/* E */      cpx,  sbc,  nop,  isb,  cpx,  sbc,  inc,  isb,  inx,  sbc,  nop,  sbc,  cpx,  sbc,  inc,  isb, /* E */
-/* F */      beq,  sbc,  nop,  nop,  nop,  sbc,  inc,  nop,  sed,  sbc,  nop,  nop,  nop,  sbc,  inc,  nop  /* F */
+/* F */      beq,  sbc,  nop,  isb,  nop,  sbc,  inc,  isb,  sed,  sbc,  nop,  isb,  nop,  sbc,  inc,  isb  /* F */
 };
 
 static const uint32_t ticktable[256] = {
@@ -741,6 +835,8 @@ void exec6502(uint32_t tickcount) {
         clockticks6502 += ticktable[opcode];
         if (penaltyop && penaltyaddr) clockticks6502++;
 
+        instructions++;
+
         if (callexternal) (*loopexternal)();
     }
 
@@ -758,6 +854,8 @@ void step6502() {
     if (penaltyop && penaltyaddr) clockticks6502++;
     clockgoal6502 = clockticks6502;
 
+    instructions++;
+
     if (callexternal) (*loopexternal)();
 }
 

src/video.c

@@ -1,117 +0,0 @@
-#include <stdlib.h>
-#include <stdint.h>
-
-#include <SFML/System.h>
-#include <SFML/Graphics.h>
-#include <SFML/Window.h>
-
-/* Public Variables */
-extern sfVertexArray *renderArray;
-int8_t videoModified;
-int8_t videoMode;
-
-/* Private Variables */
-static uint8_t video_row;
-static uint8_t video_value;
-static uint8_t video_colorValue;
-static sfColor video_displayColor;
-static sfColor video_foreColor;
-static sfColor video_backColor;
-
-const sfColor video_upperPalette = (sfColor){ 64, 64, 64 };
-
-static 	sfColor *video_colorIndex[16] = {
-	&sfBlack,					// 0x0
-	&sfRed,						// 0x1
-	&sfGreen,					// 0x2
-	&sfYellow,					// 0x3
-	&sfBlue,					// 0x4
-	&sfMagenta,					// 0x5
-	&sfCyan,					// 0x6
-	&(sfColor){ 96, 96, 96 },	// 0x7
-	
-	&(sfColor){ 162, 162, 162 },// 0x8
-	&sfRed,						// 0x9
-	&sfGreen,					// 0xA
-	&sfYellow,					// 0xB
-	&sfBlue,					// 0xC
-	&sfMagenta,					// 0xD
-	&sfCyan,					// 0xE
-	&sfWhite,					// 0xF
-};
-
-static uint8_t video_memory[0x8000];	// Empty Memory with 32k space
-
-void initVideo(){
-	renderArray = sfVertexArray_create();
-	sfVertexArray_setPrimitiveType(renderArray, sfQuads);
-	
-	videoModified = 1;
-	videoMode = 0;
-	
-	for (int i = 0x8; i < 0xF; i++){
-		//*video_colorIndex[i] = sfColor_add(*video_colorIndex[i], video_upperPalette);
-	}
-	
-	for (int i = 0; i < 0x8000; i++){
-		video_memory[i] = rand();
-	}
-}
-
-void updateVideo(){
-	sfVertexArray_clear(renderArray);
-	sfVertexArray_setPrimitiveType(renderArray, sfQuads);
-
-	videoModified = 0;
-	
-	for (int y = 0; y < 256; y++){
-		video_row = (int8_t)(y & 0x7);
-		
-		for (int x = 0; x < 48; x++){
-			
-			if (videoMode == 1){
-				/*  
-				 *           Text Address Format
-				 *           0bRRR1111AAAAAAAA
-				 * 
-				 *           R = row pins
-				 *           A = address
-				 */
-				
-				// Get text index value
-				video_value = video_memory[(((y & 0xF8) >> 3) << 7) | x];
-				
-				// Index the value in font location
-				video_value = video_memory[(video_row | 0b1111000) + (video_value * 128)];
-				video_colorValue = video_memory[(((y & 0xF8) >> 3) << 7) + (x | 0x40)];
-			}
-			else {
-				video_value = video_memory[(y * 128) + x];
-				video_colorValue = video_memory[(y * 128) + (x | 0x40)];
-			}
-			
-			// Snipping out the upper 8 colors
-			//video_colorValue &= 0x77;
-			
-			video_foreColor = *video_colorIndex[(video_colorValue & 0x0F)];
-			video_backColor = *video_colorIndex[((video_colorValue & 0xF0) >> 4)];
-			
-			
-			for (int i = 0; i < 8; i++){
-				if (video_value & (128 >> i)){
-					video_displayColor = video_foreColor;
-				} else {
-					video_displayColor = video_backColor;
-				}
-				
-				sfVertexArray_append(renderArray, (sfVertex){ (sfVector2f){ (x * 8) + i, y }, video_displayColor});
-				sfVertexArray_append(renderArray, (sfVertex){ (sfVector2f){ (x * 8) + i + 1, y }, video_displayColor});
-				sfVertexArray_append(renderArray, (sfVertex){ (sfVector2f){ (x * 8) + i + 1, y + 1 }, video_displayColor});
-				sfVertexArray_append(renderArray, (sfVertex){ (sfVector2f){ (x * 8) + i, y + 1 }, video_displayColor});
-			}
-		}
-	}
-}
-
-
-