summaryrefslogtreecommitdiffstatshomepage
path: root/src/lib/formats/mz_cas.cpp
blob: 154c4ae91c9e263af1b74dc1da8871a2ce072a78 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
// license:BSD-3-Clause
// copyright-holders:Nathan Woods
#include <string.h>
#include <assert.h>
#include "mz_cas.h"

#ifndef VERBOSE
#define VERBOSE 0
#endif

//#define LOG(N,M,A)
//  if(VERBOSE>=N){ if( M )LOG_FORMATS("%11.6f: %-24s",machine.time().as_double(), (const char*)M ); LOG_FORMATS A; }

#define LOG(N,M,A)  \
	if(VERBOSE>=N){ if( M )printf("%-24s",(const char*)M ); printf A; }

#define LO  -32768
#define HI  +32767

#define SHORT_PULSE 2
#define LONG_PULSE  4

#define BYTE_SAMPLES (LONG_PULSE+8*LONG_PULSE)

#define SILENCE     8000

/* long gap and tape mark */
#define LGAP        22000
#define LTM_1       40
#define LTM_0       40
#define LTM_L       1

/* short gap and tape mark */
#define SGAP        11000
#define STM_1       20
#define STM_0       20
#define STM_L       1

static int fill_wave_1(INT16 *buffer, int offs)
{
	buffer[offs++] = HI;
	buffer[offs++] = HI;
	buffer[offs++] = LO;
	buffer[offs++] = LO;
	return LONG_PULSE;
}

static int fill_wave_0(INT16 *buffer, int offs)
{
	buffer[offs++] = HI;
	buffer[offs++] = LO;
	return SHORT_PULSE;
}

static int fill_wave_b(INT16 *buffer, int offs, int byte)
{
	int i, count = 0;

	/* data bits are preceded by a long pulse */
	count += fill_wave_1(buffer, offs + count);

	for( i = 7; i >= 0; i-- )
	{
		if( (byte >> i) & 1 )
			count += fill_wave_1(buffer, offs + count);
		else
			count += fill_wave_0(buffer, offs + count);
	}
	return count;
}

static int fill_wave(INT16 *buffer, int length, UINT8 *code)
{
	static INT16 *beg;
	static UINT16 csum = 0;
	static int header = 1, bytecount = 0;
	int count = 0;

	if( code == CODE_HEADER )
	{
		int i;

		/* is there insufficient space for the LGAP? */
		if( count + LGAP * SHORT_PULSE > length )
			return -1;
		LOG(1,"mz700 fill_wave",("LGAP %d samples\n", LGAP * SHORT_PULSE));
		/* fill long gap */
		for( i = 0; i < LGAP; i++ )
			count += fill_wave_0(buffer, count);

		/* make a long tape mark */
		/* is there insufficient space for the LTM 1? */
		if( count + LTM_1 * LONG_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("LTM 1 %d samples\n", LTM_1 * LONG_PULSE));
		for( i = 0; i < LTM_1; i++ )
			count += fill_wave_1(buffer, count);

		/* is there insufficient space for the LTM 0? */
		if( count + LTM_0 * SHORT_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("LTM 0 %d samples\n", LTM_0 * SHORT_PULSE));
		for( i = 0; i < LTM_0; i++ )
			count += fill_wave_0(buffer, count);

		/* is there insufficient space for the L? */
		if( count + LTM_L * LONG_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("L %d samples\n", LONG_PULSE));
		count += fill_wave_1(buffer, count);

		/* reset header, bytecount and checksum */
		header = 1;
		bytecount = 0;
		csum = 0;

		/* HDR begins here */
		beg = buffer + count;

		return count;
	}

	if( code == CODE_TRAILER )
	{
		int i, file_length;
		INT16 *end = buffer;

		/* is there insufficient space for the CHKF? */
		if( count + 2 * BYTE_SAMPLES > length )
			return -1;
		LOG(1,"mz700_fill_wave",("CHKF 0x%04X\n", csum));
		count += fill_wave_b(buffer, count, csum >> 8);
		count += fill_wave_b(buffer, count, csum & 0xff);

		/* is there insufficient space for the L */
		if( count + LTM_L * LONG_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("L\n"));
		count += fill_wave_1(buffer, count);

		/* is there insufficient space for the 256S pulses? */
		if( count + 256 * SHORT_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("256S\n"));
		for (i = 0; i < 256; i++)
			count += fill_wave_0(buffer, count);

		file_length = (int)(end - beg) / sizeof(INT16);
		/* is there insufficient space for the FILEC ? */
		if( count + file_length > length )
			return -1;
		LOG(1,"mz700_fill_wave",("FILEC %d samples\n", file_length));
		memcpy(buffer + count, beg, file_length * sizeof(INT16));
		count += file_length;

		/* is there insufficient space for the CHKF ? */
		if( count + 2 * BYTE_SAMPLES > length )
			return -1;
		LOG(1,"mz700_fill_wave",("CHKF 0x%04X\n", csum));
		count += fill_wave_b(buffer, count, csum >> 8);
		count += fill_wave_b(buffer, count, csum & 0xff);

		/* is there insufficient space for the L ? */
		if( count + STM_L * LONG_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("L %d samples\n", LONG_PULSE));
		count += fill_wave_1(buffer, count);

		LOG(1,"mz700_fill_wave",("silence %d samples\n", SILENCE));
		/* silence at the end */
		for( i = 0; i < SILENCE; i++ )
			buffer[count++] = 0;

		return count;
	}

	if( header == 1 && bytecount == 128 )
	{
		int i, hdr_length;
		INT16 *end = buffer;

		/* is there insufficient space for the CHKH ? */
		if( count + 2 * BYTE_SAMPLES > length )
			return -1;
		LOG(1,"mz700_fill_wave",("CHKH 0x%04X\n", csum & 0xffff));
		count += fill_wave_b(buffer, count, (csum >> 8) & 0xff);
		count += fill_wave_b(buffer, count, csum & 0xff);

		/* is there insufficient space for the L ? */
		if( count + LONG_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("L %d samples\n", LONG_PULSE));
		count += fill_wave_1(buffer, count);

		/* is there insufficient space for the 256S ? */
		if( count + 256 * SHORT_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("256S\n"));
		for (i = 0; i < 256; i++)
			count += fill_wave_0(buffer, count);

		hdr_length = (int)(end - beg) / sizeof(INT16);
		/* is there insufficient space for the HDRC ? */
		if( count + hdr_length > length )
			return -1;
		LOG(1,"mz700_fill_wave",("HDRC %d samples\n", hdr_length));
		memcpy(buffer + count, beg, hdr_length * sizeof(INT16));
		count += hdr_length;

		/* is there insufficient space for CHKH ? */
		if( count + 2 * BYTE_SAMPLES > length )
			return -1;
		LOG(1,"mz700_fill_wave",("CHKH 0x%04X\n", csum & 0xffff));
		count += fill_wave_b(buffer, count, (csum >> 8) & 0xff);
		count += fill_wave_b(buffer, count, csum & 0xff);

		/* is there insufficient space for the L ? */
		if( count + LONG_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("L %d samples\n", LONG_PULSE));
		count += fill_wave_1(buffer, count);

		/* is there sufficient space for the SILENCE? */
		if( count + SILENCE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("SILENCE %d samples\n", SILENCE));
		/* fill silence */
		for( i = 0; i < SILENCE; i++ )
			buffer[count++] = 0;

		/* is there sufficient space for the SGAP? */
		if( count + SGAP * SHORT_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("SGAP %d samples\n", SGAP * SHORT_PULSE));
		/* fill short gap */
		for( i = 0; i < SGAP; i++ )
			count += fill_wave_0(buffer, count);

		/* make a short tape mark */

		/* is there sufficient space for the STM 1? */
		if( count + STM_1 * LONG_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("STM 1 %d samples\n", STM_1 * LONG_PULSE));
		for( i = 0; i < STM_1; i++ )
			count += fill_wave_1(buffer, count);

		/* is there sufficient space for the STM 0? */
		if( count + STM_0 * SHORT_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("STM 0 %d samples\n", STM_0 * SHORT_PULSE));
		for( i = 0; i < STM_0; i++ )
			count += fill_wave_0(buffer, count);

		/* is there sufficient space for the L? */
		if( count + STM_L * LONG_PULSE > length )
			return -1;
		LOG(1,"mz700_fill_wave",("L %d samples\n", LONG_PULSE));
		count += fill_wave_1(buffer, count);

		bytecount = 0;
		header = 0;
		csum = 0;

		/* FILE begins here */
		beg = buffer + count;
	}

	if( length < BYTE_SAMPLES )
		return -1;

	if (*code & 0x01) csum++;
	if (*code & 0x02) csum++;
	if (*code & 0x04) csum++;
	if (*code & 0x08) csum++;
	if (*code & 0x10) csum++;
	if (*code & 0x20) csum++;
	if (*code & 0x40) csum++;
	if (*code & 0x80) csum++;

	bytecount++;

	count += fill_wave_b(buffer, count, *code);

	return count;
}

#define MZ700_WAVESAMPLES_HEADER    (   \
		LGAP * SHORT_PULSE +            \
		LTM_1 * LONG_PULSE +            \
		LTM_0 * SHORT_PULSE +           \
		LTM_L * LONG_PULSE +            \
		2 * 2 * BYTE_SAMPLES +          \
	SILENCE +                           \
	SGAP * SHORT_PULSE +                \
		STM_1 * LONG_PULSE +            \
		STM_0 * SHORT_PULSE +           \
		STM_L * LONG_PULSE +            \
		2 * 2 * BYTE_SAMPLES)




static const struct CassetteLegacyWaveFiller mz700_legacy_fill_wave =
{
	fill_wave,                  /* fill_wave */
	1,                          /* chunk_size */
	2 * BYTE_SAMPLES,           /* chunk_samples */
	NULL,                       /* chunk_sample_calc */
	4400,                       // sample_frequency (tested ok with MZ-80K, MZ-80A, MZ-700, MZ-800, MZ-1500)
	MZ700_WAVESAMPLES_HEADER,   /* header_samples */
	1                           /* trailer_samples */
};



static casserr_t mz700_cas_identify(cassette_image *cassette, struct CassetteOptions *opts)
{
	return cassette_legacy_identify(cassette, opts, &mz700_legacy_fill_wave);
}



static casserr_t mz700_cas_load(cassette_image *cassette)
{
	return cassette_legacy_construct(cassette, &mz700_legacy_fill_wave);
}



static const struct CassetteFormat mz700_cas_format =
{
	"m12,mzf,mzt",
	mz700_cas_identify,
	mz700_cas_load,
	NULL
};



CASSETTE_FORMATLIST_START(mz700_cassette_formats)
	CASSETTE_FORMAT(mz700_cas_format)
CASSETTE_FORMATLIST_END