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
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
|
// license:BSD-3-Clause
// copyright-holders:Olivier Galibert
/*********************************************************************
formats/vt_dsk.cpp
VTech disk image formats
*********************************************************************/
#include "formats/vt_dsk.h"
// Zero = | 9187 |
// One = | 2237 | 6950 |
// 0.5us ~= 143
void vtech_common_format::wbit(std::vector<uint32_t> &buffer, uint32_t &pos, uint32_t &mg, bool bit)
{
buffer.push_back(pos | mg);
mg = mg == floppy_image::MG_A ? floppy_image::MG_B : floppy_image::MG_A;
if(bit) {
pos += 2237;
buffer.push_back(pos | mg);
mg = mg == floppy_image::MG_A ? floppy_image::MG_B : floppy_image::MG_A;
pos += 6950;
} else
pos += 9187;
}
void vtech_common_format::wbyte(std::vector<uint32_t> &buffer, uint32_t &pos, uint32_t &mg, uint8_t byte)
{
for(int i = 7; i >= 0; i--)
wbit(buffer, pos, mg, (byte >> i) & 1);
}
void vtech_common_format::image_to_flux(const std::vector<uint8_t> &bdata, floppy_image *image)
{
static const uint8_t sector_map[16] = {
0x0, 0xb, 0x6, 0x1, 0xc, 0x7, 0x2, 0xd, 0x8, 0x3, 0xe, 0x9, 0x4, 0xf, 0xa, 0x5
};
for(int track = 0; track != 40; track ++) {
uint32_t pos = 0;
uint32_t mg = floppy_image::MG_A;
std::vector<uint32_t> &buffer = image->get_buffer(track, 0);
buffer.clear();
image->set_write_splice_position(track, 0, 0);
// One window of pad at the start to avoid problems with the write splice
wbit(buffer, pos, mg, 0);
for(int sector = 0; sector != 16; sector ++) {
uint8_t sid = sector_map[sector];
for(int i=0; i != 7; i++)
wbyte(buffer, pos, mg, 0x80);
wbyte(buffer, pos, mg, 0x00);
wbyte(buffer, pos, mg, 0xfe);
wbyte(buffer, pos, mg, 0xe7);
wbyte(buffer, pos, mg, 0x18);
wbyte(buffer, pos, mg, 0xc3);
wbyte(buffer, pos, mg, track);
wbyte(buffer, pos, mg, sid);
wbyte(buffer, pos, mg, track+sid);
for(int i=0; i != 5; i++)
wbyte(buffer, pos, mg, 0x80);
wbyte(buffer, pos, mg, 0x00);
wbyte(buffer, pos, mg, 0xc3);
wbyte(buffer, pos, mg, 0x18);
wbyte(buffer, pos, mg, 0xe7);
wbyte(buffer, pos, mg, 0xfe);
uint16_t chk = 0;
const uint8_t *src = bdata.data() + 16*128*track + 128*sid;
for(int i=0; i != 128; i++) {
chk += src[i];
wbyte(buffer, pos, mg, src[i]);
}
wbyte(buffer, pos, mg, chk);
wbyte(buffer, pos, mg, chk >> 8);
}
// Rest is just not formatted
buffer.push_back(pos | floppy_image::MG_N);
}
}
std::vector<uint8_t> vtech_common_format::flux_to_image(floppy_image *image)
{
std::vector<uint8_t> bdata(16*256*40, 0);
for(int track = 0; track != 40; track++) {
auto buffer = image->get_buffer(track, 0);
int sz = buffer.size();
if(sz < 128)
continue;
std::vector<bool> bitstream;
int lpos = -1;
bool looped = !((buffer[sz-1] ^ buffer[0]) & floppy_image::MG_MASK);
int cpos = looped ? sz-1 : 0;
while(cpos != lpos) {
int dt = looped && cpos == sz-1 ? (200000000 - (buffer[cpos] & floppy_image::TIME_MASK)) + (buffer[1] & floppy_image::TIME_MASK) :
cpos == sz-1 ? 200000000 - (buffer[cpos] & floppy_image::TIME_MASK) :
(buffer[cpos+1] & floppy_image::TIME_MASK) - (buffer[cpos] & floppy_image::TIME_MASK);
int t = dt >= 9187 - 143 ? 0 :
dt >= 2237 - 143 && dt <= 2237 + 143 ? 1 :
2;
if(t <= 1) {
if(lpos == -1)
lpos = cpos;
bitstream.push_back(t);
}
cpos += 1;
if(cpos == sz)
cpos = looped ? 1 : 0;
}
int mode = 0;
looped = false;
int pos = 0;
int count = 0;
uint8_t *dest = nullptr;
uint16_t checksum = 0;
uint64_t buf = 0;
sz = bitstream.size();
if(sz < 128)
continue;
for(int i=0; i != 63; i++)
buf = (buf << 1) | bitstream[sz-64+i];
for(;;) {
buf = (buf << 1) | bitstream[pos];
count ++;
switch(mode) {
case 0: // idle
if(buf == 0x80808000fee718c3)
mode = 1;
count = 0;
break;
case 1: // sector header
if(count == 24) {
uint8_t trk = buf >> 16;
uint8_t sector = buf >> 8;
uint8_t chk = buf;
if(chk != sector + trk) {
mode = 0;
break;
}
checksum = 0;
dest = bdata.data() + 128 * 16 * trk + 128 * (sector & 0xf);
mode = 2;
}
break;
case 2: // look for sector data
if(buf == 0x80808000fee718c3)
mode = 1;
else if(buf == 0x80808000c318e7fe)
mode = 3;
count = 0;
break;
case 3: // sector data
if(count <= 128*8 && !(count & 7)) {
uint8_t byte = buf;
checksum += byte;
*dest++ = byte;
} else if(count == 128*8+16) {
// uint16_t disk_checksum = buf;
// printf("sector checksum %04x %04x\n", checksum, disk_checksum);
mode = 0;
}
break;
}
if(mode == 0 && looped)
break;
pos++;
if(pos == sz) {
pos = 0;
looped = true;
}
}
}
return bdata;
}
const char *vtech_bin_format::name() const
{
return "vtech_bin";
}
const char *vtech_bin_format::description() const
{
return "VTech sector disk image";
}
const char *vtech_bin_format::extensions() const
{
return "bin";
}
const char *vtech_dsk_format::name() const
{
return "vtech_dsk";
}
const char *vtech_dsk_format::description() const
{
return "VTech dsk image";
}
const char *vtech_dsk_format::extensions() const
{
return "dsk";
}
int vtech_bin_format::identify(io_generic *io, uint32_t form_factor, const std::vector<uint32_t> &variants)
{
int size = io_generic_size(io);
if(size == 40*16*256)
return 50;
return 0;
}
int vtech_dsk_format::identify(io_generic *io, uint32_t form_factor, const std::vector<uint32_t> &variants)
{
int size = io_generic_size(io);
if(size < 256)
return 0;
std::vector<uint8_t> bdata(size);
io_generic_read(io, bdata.data(), 0, size);
// Structurally validate the presence of sector headers and data
int count_sh = 0, count_sd = 0;
uint64_t buf = 0;
for(uint8_t b : bdata) {
buf = (buf << 8) | b;
if(buf == 0x80808000fee718c3)
count_sh++;
else if(buf == 0x80808000c318e7fe)
count_sd++;
}
return count_sh >= 30*16 && count_sd >= 30*16 ? 100 : 0;
}
bool vtech_bin_format::load(io_generic *io, uint32_t form_factor, const std::vector<uint32_t> &variants, floppy_image *image)
{
int size = io_generic_size(io);
if(size != 40*16*256)
return false;
std::vector<uint8_t> bdata(size);
io_generic_read(io, bdata.data(), 0, size);
image_to_flux(bdata, image);
image->set_form_variant(floppy_image::FF_525, floppy_image::SSSD);
return true;
}
bool vtech_dsk_format::load(io_generic *io, uint32_t form_factor, const std::vector<uint32_t> &variants, floppy_image *image)
{
int size = io_generic_size(io);
std::vector<uint8_t> bdata(size);
io_generic_read(io, bdata.data(), 0, size);
std::vector<uint8_t> bdatax(128*16*40, 0);
int mode = 0;
int count = 0;
uint16_t checksum = 0;
uint64_t buf = 0;
uint8_t *dest = nullptr;
for(uint8_t b : bdata) {
buf = (buf << 8) | b;
count ++;
switch(mode) {
case 0: // idle
if(buf == 0x80808000fee718c3)
mode = 1;
count = 0;
break;
case 1: // sector header
if(count == 3) {
uint8_t trk = buf >> 16;
uint8_t sector = buf >> 8;
uint8_t chk = buf;
if(chk != sector + trk) {
mode = 0;
break;
}
dest = bdatax.data() + 128*16*trk + sector*128;
checksum = 0;
mode = 2;
}
break;
case 2: // look for sector data
if(buf == 0x80808000fee718c3)
mode = 1;
else if(buf == 0x80808000c318e7fe)
mode = 3;
count = 0;
break;
case 3: // sector data
if(count <= 128) {
uint8_t byte = buf;
checksum += byte;
*dest++ = byte;
} else if(count == 128+2) {
uint16_t disk_checksum = buf;
disk_checksum = (disk_checksum << 8) | (disk_checksum >> 8);
mode = 0;
}
break;
}
}
image_to_flux(bdatax, image);
image->set_form_variant(floppy_image::FF_525, floppy_image::SSSD);
return true;
}
bool vtech_bin_format::save(io_generic *io, const std::vector<uint32_t> &variants, floppy_image *image)
{
int tracks, heads;
image->get_maximal_geometry(tracks, heads);
if(tracks < 40)
return false;
auto bdata = flux_to_image(image);
io_generic_write(io, bdata.data(), 0, bdata.size());
return true;
}
bool vtech_dsk_format::save(io_generic *io, const std::vector<uint32_t> &variants, floppy_image *image)
{
int tracks, heads;
image->get_maximal_geometry(tracks, heads);
if(tracks < 40)
return false;
auto bdata = flux_to_image(image);
std::vector<uint8_t> bdatax(0x9b*16*40);
// Format is essentially an idealized version of what's written on the disk
static const uint8_t sector_map[16] = {
0x0, 0xb, 0x6, 0x1, 0xc, 0x7, 0x2, 0xd, 0x8, 0x3, 0xe, 0x9, 0x4, 0xf, 0xa, 0x5
};
int pos = 0;
for(int track = 0; track != 40; track ++) {
for(int sector = 0; sector != 16; sector ++) {
uint8_t sid = sector_map[sector];
for(int i=0; i != 7; i++)
bdatax[pos++] = 0x80;
bdatax[pos++] = 0x00;
bdatax[pos++] = 0xfe;
bdatax[pos++] = 0xe7;
bdatax[pos++] = 0x18;
bdatax[pos++] = 0xc3;
bdatax[pos++] = track;
bdatax[pos++] = sid;
bdatax[pos++] = track+sid;
for(int i=0; i != 5; i++)
bdatax[pos++] = 0x80;
bdatax[pos++] = 0x00;
bdatax[pos++] = 0xc3;
bdatax[pos++] = 0x18;
bdatax[pos++] = 0xe7;
bdatax[pos++] = 0xfe;
uint16_t chk = 0;
const uint8_t *src = bdata.data() + 16*128*track + 128*sid;
for(int i=0; i != 128; i++) {
chk += src[i];
bdatax[pos++] = src[i];
}
bdatax[pos++] = chk;
bdatax[pos++] = chk >> 8;
}
}
io_generic_write(io, bdatax.data(), 0, bdatax.size());
return true;
}
const floppy_format_type FLOPPY_VTECH_BIN_FORMAT = &floppy_image_format_creator<vtech_bin_format>;
const floppy_format_type FLOPPY_VTECH_DSK_FORMAT = &floppy_image_format_creator<vtech_dsk_format>;
|