tape.cpp - emulators/yapesdl - Rivoreo Source Code Repositories

 /*
 	YAPE - Yet Another Plus/4 Emulator

 	The program emulates the Commodore 264 family of 8 bit microcomputers

 	This program is free software, you are welcome to distribute it,
 	and/or modify it under certain conditions. For more information,
 	read 'Copying'.

 	(c) 2000, 2001, 2005, 2016-2018 Attila Grósz
 */

 #include "tape.h"
 #include "tedmem.h"
 #include "cpu.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 static unsigned int tapFrqs[] = {
 	C64PALFREQ, C64NTSCFREQ,
 	VICPALFREQ, VICNTSCFREQ,
 	C16PALFREQ, C16NTSCFREQ
 };
 #define NROFFRQS (sizeof(tapFrqs)/sizeof(tapFrqs[0]))

 enum {
 	MTAP_IDSTRING = 0,
 	MTAP_VERSION = 12,
 	MTAP_PLATFORM,
 	MTAP_VIDEOFORMAT,
 	MTAP_RESERVED,
 	MTAP_DATASIZE
 };

 static unsigned char mtap_header_default[]={
 	'C','1','6','-','T','A','P','E','-','R','A','W',
 	0x02, // version -> 1 - "whole wave" 2 - "half wave"
 	0x02, // 0 - C64, 1 - VIC20, 2 - C16/+4
 	0x00, // Video standard ( 0= PAL, 1 =NTSC, 2 = NTSC2
 	0x00, // empty
 	// data length (4 byte) file size!!!!
 	0x00, 0x00, 0x00, 0x00
 	// data
 };

 const char tapeFormatStr[][32] = {
 	"MTAP1", "MTAP2", "PCM WAV 8-bit", "PCM WAV 16-bit", "Unknown"
 };

 TAP::TAP() : tapeFileSize(0), tapeBuffer(NULL), lastCycle(0), edge(0), buttonPressed(0), tapeSoFar(0)
 {
 	buttonPressed = motorOn = false;
 }

 bool TAP::attachTape(const char *fname)
 {
 	FILE *tapfile;

 	tapeFormat = TAPE_FORMAT_NONE;
 	if ((tapfile = fopen(fname,"rb"))) {
 		strcpy(tapefilename, fname);
 		// load TAP file into buffer
 		fseek(tapfile, 0L, SEEK_END);
 		tapeFileSize = ftell(tapfile);
 		fseek(tapfile, 0L, SEEK_SET);
 		// allocate and load file
 		tapeBuffer = new unsigned char[tapeFileSize];
 		if (fread(tapeBuffer, 1, tapeFileSize, tapfile) < 4)
 			return false;
 		tapeHeaderRead = tapeBuffer;

 		// determine the type of tape file attached
 		// MTAP?
 		if (!strncmp((const char *) tapeBuffer + 3,"-TAPE-RAW", 9)) {
 			tapeImageHeaderSize = tapeSoFar = sizeof(mtap_header_default); // offset to beginning of wave data
 			tapeFormat = (tapeHeaderRead[MTAP_VERSION] == 2) ? TAPE_FORMAT_MTAP2 : TAPE_FORMAT_MTAP1;
 			// some sanity checks for crappy TAPs
 			if (tapeHeaderRead[MTAP_PLATFORM] > 2)
 				tapeHeaderRead[MTAP_PLATFORM] = 0;
 			if (tapeHeaderRead[MTAP_VIDEOFORMAT] > 1)
 				tapeHeaderRead[MTAP_VIDEOFORMAT] = 0;
 			// set the MTAP frequency based on header
 			unsigned int index = tapeHeaderRead[MTAP_PLATFORM] * 2 + tapeHeaderRead[MTAP_VIDEOFORMAT];
 			tapeImageSampleRate = tapFrqs[index];
 			// trigger reading first pulse by starting high and no initial delay
 			edge = 0x10;
 			tapeDelay = 0;
 		// PCM WAV?
 		} else if (!memcmp(tapeBuffer, "RIFF", 4) && !memcmp(tapeBuffer + 8, "WAVEfmt ", 8)) {
 			tapeImageHeaderSize = tapeSoFar = sizeof(wav_header_t);
 			wav_header_t *wavh = (wav_header_t *)tapeHeaderRead;
 			tapeImageSampleRate = wavh->nSamplesPerSec;
 			// mono?
 			if (wavh->nChannels != 1)
 				return false;
 			tapeFormat = wavh->nBitsPerSample == 8 ? TAPE_FORMAT_PCM8 : TAPE_FORMAT_PCM16;
 		// if no match, assume it is a 44.1 kHz sample
 		} else {
 			tapeImageHeaderSize = tapeSoFar = 0;
 			tapeImageSampleRate = 44100;
 			tapeFormat = TAPE_FORMAT_PCM8;
 		}
 		motorOn = buttonPressed = false;
 		// close the file, it's in the memory now...
 		fclose(tapfile);
 		fprintf(stderr, "Tape attached    : %s\n", tapefilename);
 		fprintf(stderr, "Tape format      : %s\n", tapeFormatStr[(unsigned int)tapeFormat]);
 		fprintf(stderr, "Tape data size   : %3.1f kBytes\n", double(tapeFileSize) / 1024.0);
 		fprintf(stderr, "Tape sample rate : %u Hz\n", tapeImageSampleRate);
 		return true;
 	}
 	return false;
 }

 bool TAP::createTape(const char *fname)
 {
 	FILE *tapfile;
 	unsigned int filesize = 0;

 	if (strlen(fname) < 5)
 		return false;
 	// initialise TAP image
 	if ((tapfile = fopen(tapefilename,"wb"))) {
 		strcpy(tapefilename, fname);
 		// write the header
 		fwrite(mtap_header_default, sizeof(mtap_header_default), 1, tapfile);
 		fwrite(&filesize, 4, 1, tapfile);
 		return true;
 	}
 	else
 		return false;
 }

 bool TAP::detachTape()
 {
 	//if (tapfile != NULL && TapeSoFar > 0) {
 	//	fseek(tapfile, 0x10L, SEEK_SET);
 	//	fwrite(&TapeSoFar, sizeof(TapeSoFar), 1, tapfile);
 	//	fseek(tapfile, 0L, SEEK_END);
 	//  fclose(tapfile);
 	//  tapfile = NULL;
 	//}
 	if (tapeBuffer != NULL) { // just to be sure....
 		delete [] tapeBuffer;
 		tapeBuffer = NULL;
 	}
 	tapeSoFar = 0;
 	return false;
 }

 void TAP::rewind()
 {
 	tapeSoFar = tapeImageHeaderSize;
 	if (tapeFormat <= TAPE_FORMAT_MTAP2) {
 		// start high since XOR is triggered
 		edge = 0x10;
 		tapeDelay = 0;
 	} else
 		edge = 0x00;
 }

 void TAP::changewave(bool wholewave)
 {
 	mtap_header_default[MTAP_VERSION] = wholewave ? 1 : 2;
 }

 inline void TAP::readMtapData(unsigned int elapsed)
 {
 	while (elapsed--) {
 		if (!tapeDelay--) {
 			//fprintf( stderr, "TAP unit timeout in cycle: %u\n", elapsed);
 			if (edge == 0x10) {
 				convTAPUnitsToCycles();
 				fallingEdge = true;
 			} else {
 				tapeDelay = origTapeDelay;
 			}
 			edge ^= 0x10;
 		}
 	}
 }

 inline void TAP::readWavData(unsigned int elapsed)
 {
 	const unsigned int fastClockFreq = mem->getRealSlowClock() << 1;
 	static int prevSample = 0;

 	while (elapsed--) {
 		if (tapeSoFar >= tapeFileSize)
 			return;
 		if ((tapeDelay += tapeImageSampleRate) >= fastClockFreq) {
 			int sample = tapeBuffer[tapeSoFar++];

 			if (tapeFormat == TAPE_FORMAT_PCM16) {
 				sample += tapeBuffer[tapeSoFar++] << 8;
 				int change = short(sample) - prevSample;
 				if (sample > 0 && change > 0) {
 					edge = 0x10;
 				} else if (sample <= 0 && change < 0) {
 					edge = 0x00;
 					fallingEdge = true;
 				}
 			} else {
 				int change = sample - prevSample;
 				if (sample > 0x80 && change > 0) {
 					edge = 0x10;
 				} else if (sample <= 0x7F && change < 0) {
 					edge = 0x00;
 					fallingEdge = true;
 				}
 			}
 			prevSample = sample;
 			tapeDelay -= fastClockFreq;
 		}
 	}
 }

 unsigned char TAP::readCSTIn(ClockCycle cycle)
 {
 	int elapsed = int(cycle - lastCycle);

 	if (motorOn && tapeBuffer) {
 		switch (tapeFormat) {
 			case TAPE_FORMAT_MTAP1:
 			case TAPE_FORMAT_MTAP2:
 				readMtapData(elapsed);
 				break;
 			case TAPE_FORMAT_PCM8:
 				readWavData(elapsed);
 				break;
 			case TAPE_FORMAT_NONE:
 			default:
 				break;
 		}
 		lastCycle = cycle;
 	}
 	return edge;
 }

 inline unsigned int TAP::readNextTapDelay()
 {
 	unsigned int delay = tapeBuffer[tapeSoFar++];

 	/* byte $00 is a pilot byte */
 	if (!delay) {
 		delay = tapeBuffer[tapeSoFar++];
 		delay += tapeBuffer[tapeSoFar++] << 8;
 		delay += tapeBuffer[tapeSoFar++] << 16;
 		/*fprintf( stderr, "Pilot byte %i.\n", delay);
 		fprintf( stderr, "Pilot offset: %i.\n", TapeSoFar);*/
 	} else {
 		delay <<= 3;
 	}
 	unsigned int tapClockFreq = mem->getRealSlowClock() >> 4;
 	// machine clock frequency different from MTAP one? then adjust...
 	if (tapeImageSampleRate != tapClockFreq) {
 		const double frqMult = double(tapClockFreq) / double(tapeImageSampleRate);
 		delay = (unsigned int)(double(delay) * frqMult + 0.5);
 	}
 	if (tapeSoFar >= tapeFileSize) {
 		motorOn = buttonPressed = false;
 	}
 	return delay << 1;
 }

 void TAP::convTAPUnitsToCycles()
 {
 	if (tapeFormat == TAPE_FORMAT_MTAP1) {
 		origTapeDelay = readNextTapDelay();
 		tapeDelay = origTapeDelay >> 1;
 		origTapeDelay -= tapeDelay;
 	} else {
 		tapeDelay = readNextTapDelay();
 		origTapeDelay = readNextTapDelay();
 	}
 	//fprintf(stderr, "New TAP delay value: %u\n", tapeDelay);
 }

 void TAP::pressTapeButton(ClockCycle cycle, unsigned int pressed)
 {
 	if (pressed) {
 		buttonPressed = 1;
 	} else {
 		buttonPressed = 0;
 		motorOn = false;
 	}
 }

 void TAP::setTapeMotor(ClockCycle cycle, unsigned int on)
 {
 	if (!on && motorOn)
 		readCSTIn(cycle);
 	else if (on && !motorOn)
 		lastCycle = cycle;
 	motorOn = (on != 0);
 	//fprintf( stderr, "Motor state: %i, in cycle %u\n", motorOn, cycle);
 }
	/*
	YAPE - Yet Another Plus/4 Emulator

	The program emulates the Commodore 264 family of 8 bit microcomputers

	This program is free software, you are welcome to distribute it,
	and/or modify it under certain conditions. For more information,
	read 'Copying'.

	(c) 2000, 2001, 2005, 2016-2018 Attila Grósz
	*/

	#include "tape.h"
	#include "tedmem.h"
	#include "cpu.h"
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>

	static unsigned int tapFrqs[] = {
	C64PALFREQ, C64NTSCFREQ,
	VICPALFREQ, VICNTSCFREQ,
	C16PALFREQ, C16NTSCFREQ
	};
	#define NROFFRQS (sizeof(tapFrqs)/sizeof(tapFrqs[0]))

	enum {
	MTAP_IDSTRING = 0,
	MTAP_VERSION = 12,
	MTAP_PLATFORM,
	MTAP_VIDEOFORMAT,
	MTAP_RESERVED,
	MTAP_DATASIZE
	};

	static unsigned char mtap_header_default[]={
	'C','1','6','-','T','A','P','E','-','R','A','W',
	0x02, // version -> 1 - "whole wave" 2 - "half wave"
	0x02, // 0 - C64, 1 - VIC20, 2 - C16/+4
	0x00, // Video standard ( 0= PAL, 1 =NTSC, 2 = NTSC2
	0x00, // empty
	// data length (4 byte) file size!!!!
	0x00, 0x00, 0x00, 0x00
	// data
	};

	const char tapeFormatStr[][32] = {
	"MTAP1", "MTAP2", "PCM WAV 8-bit", "PCM WAV 16-bit", "Unknown"
	};

	TAP::TAP() : tapeFileSize(0), tapeBuffer(NULL), lastCycle(0), edge(0), buttonPressed(0), tapeSoFar(0)
	{
	buttonPressed = motorOn = false;
	}

	bool TAP::attachTape(const char *fname)
	{
	FILE *tapfile;

	tapeFormat = TAPE_FORMAT_NONE;
	if ((tapfile = fopen(fname,"rb"))) {
	strcpy(tapefilename, fname);
	// load TAP file into buffer
	fseek(tapfile, 0L, SEEK_END);
	tapeFileSize = ftell(tapfile);
	fseek(tapfile, 0L, SEEK_SET);
	// allocate and load file
	tapeBuffer = new unsigned char[tapeFileSize];
	if (fread(tapeBuffer, 1, tapeFileSize, tapfile) < 4)
	return false;
	tapeHeaderRead = tapeBuffer;

	// determine the type of tape file attached
	// MTAP?
	if (!strncmp((const char *) tapeBuffer + 3,"-TAPE-RAW", 9)) {
	tapeImageHeaderSize = tapeSoFar = sizeof(mtap_header_default); // offset to beginning of wave data
	tapeFormat = (tapeHeaderRead[MTAP_VERSION] == 2) ? TAPE_FORMAT_MTAP2 : TAPE_FORMAT_MTAP1;
	// some sanity checks for crappy TAPs
	if (tapeHeaderRead[MTAP_PLATFORM] > 2)
	tapeHeaderRead[MTAP_PLATFORM] = 0;
	if (tapeHeaderRead[MTAP_VIDEOFORMAT] > 1)
	tapeHeaderRead[MTAP_VIDEOFORMAT] = 0;
	// set the MTAP frequency based on header
	unsigned int index = tapeHeaderRead[MTAP_PLATFORM] * 2 + tapeHeaderRead[MTAP_VIDEOFORMAT];
	tapeImageSampleRate = tapFrqs[index];
	// trigger reading first pulse by starting high and no initial delay
	edge = 0x10;
	tapeDelay = 0;
	// PCM WAV?
	} else if (!memcmp(tapeBuffer, "RIFF", 4) && !memcmp(tapeBuffer + 8, "WAVEfmt ", 8)) {
	tapeImageHeaderSize = tapeSoFar = sizeof(wav_header_t);
	wav_header_t wavh = (wav_header_t )tapeHeaderRead;
	tapeImageSampleRate = wavh->nSamplesPerSec;
	// mono?
	if (wavh->nChannels != 1)
	return false;
	tapeFormat = wavh->nBitsPerSample == 8 ? TAPE_FORMAT_PCM8 : TAPE_FORMAT_PCM16;
	// if no match, assume it is a 44.1 kHz sample
	} else {
	tapeImageHeaderSize = tapeSoFar = 0;
	tapeImageSampleRate = 44100;
	tapeFormat = TAPE_FORMAT_PCM8;
	}
	motorOn = buttonPressed = false;
	// close the file, it's in the memory now...
	fclose(tapfile);
	fprintf(stderr, "Tape attached : %s\n", tapefilename);
	fprintf(stderr, "Tape format : %s\n", tapeFormatStr[(unsigned int)tapeFormat]);
	fprintf(stderr, "Tape data size : %3.1f kBytes\n", double(tapeFileSize) / 1024.0);
	fprintf(stderr, "Tape sample rate : %u Hz\n", tapeImageSampleRate);
	return true;
	}
	return false;
	}

	bool TAP::createTape(const char *fname)
	{
	FILE *tapfile;
	unsigned int filesize = 0;

	if (strlen(fname) < 5)
	return false;
	// initialise TAP image
	if ((tapfile = fopen(tapefilename,"wb"))) {
	strcpy(tapefilename, fname);
	// write the header
	fwrite(mtap_header_default, sizeof(mtap_header_default), 1, tapfile);
	fwrite(&filesize, 4, 1, tapfile);
	return true;
	}
	else
	return false;
	}

	bool TAP::detachTape()
	{
	//if (tapfile != NULL && TapeSoFar > 0) {
	// fseek(tapfile, 0x10L, SEEK_SET);
	// fwrite(&TapeSoFar, sizeof(TapeSoFar), 1, tapfile);
	// fseek(tapfile, 0L, SEEK_END);
	// fclose(tapfile);
	// tapfile = NULL;
	//}
	if (tapeBuffer != NULL) { // just to be sure....
	delete [] tapeBuffer;
	tapeBuffer = NULL;
	}
	tapeSoFar = 0;
	return false;
	}

	void TAP::rewind()
	{
	tapeSoFar = tapeImageHeaderSize;
	if (tapeFormat <= TAPE_FORMAT_MTAP2) {
	// start high since XOR is triggered
	edge = 0x10;
	tapeDelay = 0;
	} else
	edge = 0x00;
	}

	void TAP::changewave(bool wholewave)
	{
	mtap_header_default[MTAP_VERSION] = wholewave ? 1 : 2;
	}

	inline void TAP::readMtapData(unsigned int elapsed)
	{
	while (elapsed--) {
	if (!tapeDelay--) {
	//fprintf( stderr, "TAP unit timeout in cycle: %u\n", elapsed);
	if (edge == 0x10) {
	convTAPUnitsToCycles();
	fallingEdge = true;
	} else {
	tapeDelay = origTapeDelay;
	}
	edge ^= 0x10;
	}
	}
	}

	inline void TAP::readWavData(unsigned int elapsed)
	{
	const unsigned int fastClockFreq = mem->getRealSlowClock() << 1;
	static int prevSample = 0;

	while (elapsed--) {
	if (tapeSoFar >= tapeFileSize)
	return;
	if ((tapeDelay += tapeImageSampleRate) >= fastClockFreq) {
	int sample = tapeBuffer[tapeSoFar++];

	if (tapeFormat == TAPE_FORMAT_PCM16) {
	sample += tapeBuffer[tapeSoFar++] << 8;
	int change = short(sample) - prevSample;
	if (sample > 0 && change > 0) {
	edge = 0x10;
	} else if (sample <= 0 && change < 0) {
	edge = 0x00;
	fallingEdge = true;
	}
	} else {
	int change = sample - prevSample;
	if (sample > 0x80 && change > 0) {
	edge = 0x10;
	} else if (sample <= 0x7F && change < 0) {
	edge = 0x00;
	fallingEdge = true;
	}
	}
	prevSample = sample;
	tapeDelay -= fastClockFreq;
	}
	}
	}

	unsigned char TAP::readCSTIn(ClockCycle cycle)
	{
	int elapsed = int(cycle - lastCycle);

	if (motorOn && tapeBuffer) {
	switch (tapeFormat) {
	case TAPE_FORMAT_MTAP1:
	case TAPE_FORMAT_MTAP2:
	readMtapData(elapsed);
	break;
	case TAPE_FORMAT_PCM8:
	readWavData(elapsed);
	break;
	case TAPE_FORMAT_NONE:
	default:
	break;
	}
	lastCycle = cycle;
	}
	return edge;
	}

	inline unsigned int TAP::readNextTapDelay()
	{
	unsigned int delay = tapeBuffer[tapeSoFar++];

	/* byte $00 is a pilot byte */
	if (!delay) {
	delay = tapeBuffer[tapeSoFar++];
	delay += tapeBuffer[tapeSoFar++] << 8;
	delay += tapeBuffer[tapeSoFar++] << 16;
	/*fprintf( stderr, "Pilot byte %i.\n", delay);
	fprintf( stderr, "Pilot offset: %i.\n", TapeSoFar);*/
	} else {
	delay <<= 3;
	}
	unsigned int tapClockFreq = mem->getRealSlowClock() >> 4;
	// machine clock frequency different from MTAP one? then adjust...
	if (tapeImageSampleRate != tapClockFreq) {
	const double frqMult = double(tapClockFreq) / double(tapeImageSampleRate);
	delay = (unsigned int)(double(delay) * frqMult + 0.5);
	}
	if (tapeSoFar >= tapeFileSize) {
	motorOn = buttonPressed = false;
	}
	return delay << 1;
	}

	void TAP::convTAPUnitsToCycles()
	{
	if (tapeFormat == TAPE_FORMAT_MTAP1) {
	origTapeDelay = readNextTapDelay();
	tapeDelay = origTapeDelay >> 1;
	origTapeDelay -= tapeDelay;
	} else {
	tapeDelay = readNextTapDelay();
	origTapeDelay = readNextTapDelay();
	}
	//fprintf(stderr, "New TAP delay value: %u\n", tapeDelay);
	}

	void TAP::pressTapeButton(ClockCycle cycle, unsigned int pressed)
	{
	if (pressed) {
	buttonPressed = 1;
	} else {
	buttonPressed = 0;
	motorOn = false;
	}
	}

	void TAP::setTapeMotor(ClockCycle cycle, unsigned int on)
	{
	if (!on && motorOn)
	readCSTIn(cycle);
	else if (on && !motorOn)
	lastCycle = cycle;
	motorOn = (on != 0);
	//fprintf( stderr, "Motor state: %i, in cycle %u\n", motorOn, cycle);
	}