added support for more mappers and corrected another audio mute bug

README.md

@@ -3,7 +3,7 @@ This is yet another NES Emulator which was written so I can learn about the NES,
 If you want to check it out for some reason I do include a windows binary in the "Releases" tab, if you want to compile it go check out the "build" files.  
 You will need freeglut as well as openal-soft to compile the project, it should run on most systems since it is fairly generic C code.  
 NTSC and PAL .nes ROMs are supported right now, it also creates .sav files if the chosen game supports saving.  
-Supported Mappers: 0,1,2,3,4,7,9,10,11,13,15,21,22,23,24,25,26,33,34,36,37,38,44,45,46,47,48,52,66,70,71,78,79,85,87,94,97,99,101,113,133,140,144,145,146,147,148,149,152,180,185,240 and 242.  
+Supported Mappers: 0,1,2,3,4,7,9,10,11,13,15,21,22,23,24,25,26,33,34,36,37,38,44,45,46,47,48,52,61,66,70,71,75,78,79,85,87,89,93,94,97,99,101,113,133,140,144,145,146,147,148,149,152,180,184,185,240 and 242.  
 To start a game, simply drag and drop its .nes file into it or call it via command line with the .nes file as argument.  
 If you are starting a PAL NES title then make sure it has (E) in the name to be started in PAL mode.  
 You can also play FDS titles if you have the FDS BIOS named disksys.rom in the same folder as your .fds/.qd files.  

apu.c

@@ -575,6 +575,8 @@ void apuSet8(uint8_t reg, uint8_t val)
 		p1seq = pulseSeqs[val>>6];
 		p1Env.constant = ((val&PULSE_CONST_V) != 0);
 		p1Env.loop = p1haltloop = ((val&PULSE_HALT_LOOP) != 0);
+		if(freq1 > 8 && (freq1 < 0x7FF))
+			p1Sweep.mute = false; //to be safe
 	}
 	else if(reg == 1)
 	{
@@ -584,19 +586,25 @@ void apuSet8(uint8_t reg, uint8_t val)
 		p1Sweep.period = (val>>4)&7;
 		p1Sweep.negative = ((val&0x8) != 0);
 		p1Sweep.start = true;
+		if(freq1 > 8 && (freq1 < 0x7FF))
+			p1Sweep.mute = false; //to be safe
 		doSweepLogic(&p1Sweep, &freq1);
 	}
 	else if(reg == 2)
 	{
 		//printf("P1 time low %02x\n", val);
 		freq1 = ((freq1&~0xFF) | val);
+		if(freq1 > 8 && (freq1 < 0x7FF))
+			p1Sweep.mute = false; //to be safe
 	}
 	else if(reg == 3)
 	{
 		p1Cycle = 0;
 		if(APU_IO_Reg[0x15] & P1_ENABLE)
 			p1LengthCtr = lengthLookupTbl[val>>3];
 		freq1 = (freq1&0xFF) | ((val&7)<<8);
+		if(freq1 > 8 && (freq1 < 0x7FF))
+			p1Sweep.mute = false; //to be safe
 		//printf("P1 new freq %04x\n", freq1);
 		p1Env.start = true;
 	}
@@ -606,6 +614,8 @@ void apuSet8(uint8_t reg, uint8_t val)
 		p2seq = pulseSeqs[val>>6];
 		p2Env.constant = ((val&PULSE_CONST_V) != 0);
 		p2Env.loop = p2haltloop = ((val&PULSE_HALT_LOOP) != 0);
+		if(freq2 > 8 && (freq2 < 0x7FF))
+			p2Sweep.mute = false; //to be safe
 	}
 	else if(reg == 5)
 	{
@@ -615,19 +625,25 @@ void apuSet8(uint8_t reg, uint8_t val)
 		p2Sweep.period = (val>>4)&7;
 		p2Sweep.negative = ((val&0x8) != 0);
 		p2Sweep.start = true;
+		if(freq2 > 8 && (freq2 < 0x7FF))
+			p2Sweep.mute = false; //to be safe
 		doSweepLogic(&p2Sweep, &freq2);
 	}
 	else if(reg == 6)
 	{
 		//printf("P2 time low %02x\n", val);
 		freq2 = ((freq2&~0xFF) | val);
+		if(freq2 > 8 && (freq2 < 0x7FF))
+			p2Sweep.mute = false; //to be safe
 	}
 	else if(reg == 7)
 	{
 		p2Cycle = 0;
 		if(APU_IO_Reg[0x15] & P2_ENABLE)
 			p2LengthCtr = lengthLookupTbl[val>>3];
 		freq2 = (freq2&0xFF) | ((val&7)<<8);
+		if(freq2 > 8 && (freq2 < 0x7FF))
+			p2Sweep.mute = false; //to be safe
 		//printf("P2 new freq %04x\n", freq2);
 		p2Env.start = true;
 	}

main.c

@@ -30,7 +30,7 @@
 #define DEBUG_KEY 0
 #define DEBUG_LOAD_INFO 1
 
-static const char *VERSION_STRING = "fixNES Alpha v0.8.1";
+static const char *VERSION_STRING = "fixNES Alpha v0.8.2";
 
 static void nesEmuDisplayFrame(void);
 static void nesEmuMainLoop(void);
@@ -132,6 +132,11 @@ int main(int argc, char** argv)
 		memInit();
 		apuInit();
 		inputInit();
+		#if DEBUG_LOAD_INFO
+		printf("Read in %s\n", argv[1]);
+		printf("Used Mapper: %i\n", mapper);
+		printf("PRG: 0x%x bytes PRG RAM: 0x%x bytes CHR: 0x%x bytes\n", prgROMsize, emuPrgRAMsize, chrROMsize);
+		#endif
 		if(!mapperInit(mapper, prgROM, prgROMsize, emuPrgRAM, emuPrgRAMsize, chrROM, chrROMsize))
 		{
 			printf("Mapper init failed!\n");
@@ -146,9 +151,6 @@ int main(int argc, char** argv)
 		else
 			ppuSetNameTblHorizontal();
 		#if DEBUG_LOAD_INFO
-		printf("Read in %s\n", argv[1]);
-		printf("Used Mapper: %i\n", mapper);
-		printf("PRG: 0x%x bytes PRG RAM: 0x%x bytes CHR: 0x%x bytes\n", prgROMsize, emuPrgRAMsize, chrROMsize);
 		printf("Trainer: %i Saving: %i VRAM Mode: %s\n", trainer, emuSaveEnabled, (emuNesROM[6] & 1) ? "Vertical" : 
 			((!(emuNesROM[6] & 1)) ? "Horizontal" : "4-Screen"));
 		#endif

mapper/m4.c

@@ -28,6 +28,8 @@ static bool m4_chr_bank_flip;
 static bool m4_prg_bank_flip;
 static uint8_t m4_irqCtr;
 static bool m4_irqEnable;
+static bool m4_altirq;
+static bool m4_clear;
 static uint8_t m4_irqReloadVal;
 static uint8_t m4_irqCooldown;
 static uint8_t m4_irqStart;
@@ -71,6 +73,9 @@ void m4init(uint8_t *prgROMin, uint32_t prgROMsizeIn,
 	m4_irqStart = 0;
 	m4_writeAddr = 0;
 	m4_irqEnable = false;
+	//can enable MMC3A IRQ behaviour
+	m4_altirq = false;
+	m4_clear = false;
 	m4_irqReloadVal = 0xFF;
 	m4_irqCooldown = 0;
 	m4_chr_bank_flip = false;
@@ -187,6 +192,8 @@ void m4set8(uint16_t addr, uint8_t val)
 			{
 				//printf("Reload value set to %i\n", val);
 				m4_irqReloadVal = val;
+				if(m4_altirq)
+					m4_clear = true;
 			}
 			else
 			{
@@ -220,19 +227,18 @@ void m4clock(uint16_t addr)
 		if(m4_irqCooldown == 0)
 		{
 			//printf("MMC3 Beep at %i %i\n", curLine, curDot);
-			if(m4_irqCtr == 0)
+			uint8_t oldCtr = m4_irqCtr;
+			if(m4_irqCtr == 0 || m4_clear)
 				m4_irqCtr = m4_irqReloadVal;
 			else
 				m4_irqCtr--;
-			if(m4_irqCtr == 0)
+			if((!m4_altirq || oldCtr != 0 || m4_clear) && m4_irqCtr == 0 && m4_irqEnable)
 			{
-				if(m4_irqEnable)
-				{
-					//printf("MMC3 Tick at %i %i\n", curLine, curDot);
-					m4_irqStart = 5; //takes a bit before trigger
-					m4_irqEnable = false;
-				}
+				//printf("MMC3 Tick at %i %i\n", curLine, curDot);
+				m4_irqStart = 5; //takes a bit before trigger
+				m4_irqEnable = false;
 			}
+			m4_clear = false;
 		}
 		//make sure to pass all other sprites
 		//before counting up again

mapper/p16c4.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2017 FIX94
+ *
+ * This software may be modified and distributed under the terms
+ * of the MIT license.  See the LICENSE file for details.
+ */
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <inttypes.h>
+#include "../ppu.h"
+
+static uint8_t *p16c4_prgROM;
+static uint8_t *p16c4_chrROM;
+static uint32_t p16c4_prgROMsize;
+static uint32_t p16c4_chrROMsize;
+static uint32_t p16c4_firstPRGBank;
+static uint32_t p16c4_curPRGBank;
+static uint32_t p16c4_curCHRBank0;
+static uint32_t p16c4_curCHRBank1;
+static uint32_t p16c4_lastPRGBank;
+
+static uint8_t p16c4_chrRAM[0x2000];
+
+void p16c4init(uint8_t *prgROMin, uint32_t prgROMsizeIn, 
+			uint8_t *prgRAMin, uint32_t prgRAMsizeIn,
+			uint8_t *chrROMin, uint32_t chrROMsizeIn)
+{
+	p16c4_prgROM = prgROMin;
+	p16c4_prgROMsize = prgROMsizeIn;
+	(void)prgRAMin;
+	(void)prgRAMsizeIn;
+	p16c4_firstPRGBank = 0;
+	p16c4_curPRGBank = p16c4_firstPRGBank;
+	p16c4_lastPRGBank = prgROMsizeIn - 0x4000;
+	if(chrROMsizeIn > 0)
+	{
+		p16c4_chrROM = chrROMin;
+		p16c4_chrROMsize = chrROMsizeIn;
+	}
+	else
+	{
+		p16c4_chrROM = p16c4_chrRAM;
+		p16c4_chrROMsize = 0x2000;
+		memset(p16c4_chrRAM,0,0x2000);
+	}
+	p16c4_curCHRBank0 = 0;
+	p16c4_curCHRBank1 = 0;
+	printf("16k PRG 4k CHR Mapper inited\n");
+}
+
+uint8_t p16c4get8(uint16_t addr, uint8_t val)
+{
+	if(addr < 0x8000)
+		return val;
+	if(addr < 0xC000)
+		return p16c4_prgROM[((p16c4_curPRGBank&~0x3FFF)+(addr&0x3FFF))&(p16c4_prgROMsize-1)];
+	return p16c4_prgROM[((p16c4_lastPRGBank&~0x3FFF)+(addr&0x3FFF))&(p16c4_prgROMsize-1)];
+}
+
+void m184_set8(uint16_t addr, uint8_t val)
+{
+	//printf("p16c4set8 %04x %02x\n", addr, val);
+	if(addr >= 0x6000 && addr < 0x8000)
+	{
+		p16c4_curCHRBank0 = ((val & 0x7)<<12)&(p16c4_chrROMsize-1);
+		p16c4_curCHRBank1 = (((val>>4) & 0x7)<<12)&(p16c4_chrROMsize-1);
+	}
+	else if(addr >= 0x8000)
+		p16c4_curPRGBank = (((val>>4) & 0x7)<<14)&(p16c4_prgROMsize-1);
+}
+
+uint8_t p16c4chrGet8(uint16_t addr)
+{
+	if(p16c4_chrROM == p16c4_chrRAM) //Writable
+		return p16c4_chrROM[addr&0x1FFF];
+	if(addr < 0x1000) //Banked
+		return p16c4_chrROM[((p16c4_curCHRBank0&~0xFFF)+(addr&0xFFF))&(p16c4_chrROMsize-1)];
+	return p16c4_chrROM[((p16c4_curCHRBank1&~0xFFF)+(addr&0xFFF))&(p16c4_chrROMsize-1)];
+}
+
+void p16c4chrSet8(uint16_t addr, uint8_t val)
+{
+	if(p16c4_chrROM == p16c4_chrRAM) //Writable
+		p16c4_chrROM[addr&0x1FFF] = val;
+}

mapper/p16c8.c

@@ -18,6 +18,7 @@ static uint32_t p16c8_firstPRGBank;
 static uint32_t p16c8_curPRGBank;
 static uint32_t p16c8_curCHRBank;
 static uint32_t p16c8_lastPRGBank;
+static bool m61_p16;
 
 static uint8_t p16c8_chrRAM[0x2000];
 
@@ -44,6 +45,7 @@ void p16c8init(uint8_t *prgROMin, uint32_t prgROMsizeIn,
 		memset(p16c8_chrRAM,0,0x2000);
 	}
 	p16c8_curCHRBank = 0;
+	m61_p16 = false;
 	printf("16k PRG 8k CHR Mapper inited\n");
 }
 
@@ -56,6 +58,13 @@ uint8_t p16c8get8(uint16_t addr, uint8_t val)
 	return p16c8_prgROM[((p16c8_lastPRGBank&~0x3FFF)+(addr&0x3FFF))&(p16c8_prgROMsize-1)];
 }
 
+uint8_t m61_get8(uint16_t addr, uint8_t val)
+{
+	if(addr < 0x8000)
+		return val;
+	return p16c8_prgROM[((p16c8_curPRGBank&~0x3FFF)+(addr&(m61_p16?0x3FFF:0x7FFF)))&(p16c8_prgROMsize-1)];
+}
+
 uint8_t m97_get8(uint16_t addr, uint8_t val)
 {
 	if(addr < 0x8000)
@@ -82,6 +91,19 @@ void m2_set8(uint16_t addr, uint8_t val)
 	p16c8_curPRGBank = ((val & 0xF)<<14)&(p16c8_prgROMsize-1);
 }
 
+void m61_set8(uint16_t addr, uint8_t val)
+{
+	(void)val;
+	if(addr < 0x8000)
+		return;
+	p16c8_curPRGBank = ((((addr & 0xF)<<1)|((addr&0x20)>>5))<<14)&(p16c8_prgROMsize-1);;
+	m61_p16 = ((addr&0x10) != 0);
+	if((addr&0x80) != 0)
+		ppuSetNameTblHorizontal();
+	else
+		ppuSetNameTblVertical();
+}
+
 void m70_set8(uint16_t addr, uint8_t val)
 {
 	//printf("p16c8set8 %04x %02x\n", addr, val);
@@ -125,6 +147,27 @@ void m78b_set8(uint16_t addr, uint8_t val)
 		ppuSetNameTblSingleUpper();
 }
 
+void m89_set8(uint16_t addr, uint8_t val)
+{
+	//printf("p16c8set8 %04x %02x\n", addr, val);
+	if(addr < 0x8000)
+		return;
+	p16c8_curPRGBank = (((val>>4) & 7)<<14)&(p16c8_prgROMsize-1);
+	p16c8_curCHRBank = ((((val&0x80)>>4)|(val & 7))<<13)&(p16c8_chrROMsize-1);
+	if((val&0x8) == 0)
+		ppuSetNameTblSingleLower();
+	else
+		ppuSetNameTblSingleUpper();
+}
+
+void m93_set8(uint16_t addr, uint8_t val)
+{
+	//printf("p16c8set8 %04x %02x\n", addr, val);
+	if(addr < 0x8000)
+		return;
+	p16c8_curPRGBank = (((val>>4) & 7)<<14)&(p16c8_prgROMsize-1);
+}
+
 void m94_set8(uint16_t addr, uint8_t val)
 {
 	//printf("p16c8set8 %04x %02x\n", addr, val);