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comparison cdd_mcu.c @ 2076:3f29e2726522

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Added basic support for ISO images for games that only have a data track
author Michael Pavone <pavone@retrodev.com>
date Mon, 31 Jan 2022 22:07:18 -0800
parents 983f57d08eff
children c534a3199020
comparison
equal deleted inserted replaced
2075:983f57d08eff 2076:3f29e2726522
37 void cdd_mcu_init(cdd_mcu *context, system_media *media) 37 void cdd_mcu_init(cdd_mcu *context, system_media *media)
38 { 38 {
39 context->next_int_cycle = CYCLE_NEVER; 39 context->next_int_cycle = CYCLE_NEVER;
40 context->last_subcode_cycle = CYCLE_NEVER; 40 context->last_subcode_cycle = CYCLE_NEVER;
41 context->last_nibble_cycle = CYCLE_NEVER; 41 context->last_nibble_cycle = CYCLE_NEVER;
42 context->last_byte_cycle = CYCLE_NEVER;
42 context->requested_format = SF_NOTREADY; 43 context->requested_format = SF_NOTREADY;
43 context->media = media; 44 context->media = media;
44 context->current_status_nibble = -1; 45 context->current_status_nibble = -1;
45 context->current_cmd_nibble = -1; 46 context->current_cmd_nibble = -1;
47 context->current_sector_byte = -1;
46 } 48 }
47 49
48 enum { 50 enum {
49 GAO_CDD_CTRL, 51 GAO_CDD_CTRL,
50 GAO_CDD_STATUS, 52 GAO_CDD_STATUS,
109 { 111 {
110 case DS_PLAY: 112 case DS_PLAY:
111 handle_seek(context); 113 handle_seek(context);
112 if (!context->seeking) { 114 if (!context->seeking) {
113 context->head_pba++; 115 context->head_pba++;
114 uint32_t lba = context->head_pba - LEADIN_SECTORS; 116 context->media->seek(context->media, context->head_pba - LEADIN_SECTORS);
115 for (uint32_t i = 0; i < context->media->num_tracks; i++)
116 {
117 if (lba < context->media->tracks[i].fake_pregap) {
118 context->in_fake_pregap = 1;
119 break;
120 }
121 lba -= context->media->tracks[i].fake_pregap;
122 if (lba < context->media->tracks[i].start_lba) {
123 context->in_fake_pregap = 1;
124 break;
125 }
126 if (lba < context->media->tracks[i].end_lba) {
127 fseek(context->media->f, lba * 2352, SEEK_SET);
128 context->in_fake_pregap = 0;
129 break;
130 }
131 }
132 } 117 }
133 break; 118 break;
134 case DS_PAUSE: 119 case DS_PAUSE:
135 handle_seek(context); 120 handle_seek(context);
136 break; 121 break;
521 context->last_nibble_cycle = context->cycle; 506 context->last_nibble_cycle = context->cycle;
522 next_cmd_nibble = context->cycle + NIBBLE_CLOCKS; 507 next_cmd_nibble = context->cycle + NIBBLE_CLOCKS;
523 } 508 }
524 } 509 }
525 if (context->cycle >= next_byte) { 510 if (context->cycle >= next_byte) {
526 uint8_t byte; 511 uint8_t byte = context->media->read(context->media, context->current_sector_byte);
527 if (context->in_fake_pregap) {
528 if (!context->current_sector_byte || (context->current_sector_byte >= 16)) {
529 byte = 0;
530 //TODO: error detection and correction bytes
531 } else if (context->current_sector_byte < 12) {
532 byte = 0xFF;
533 } else if (context->current_sector_byte == 12) {
534 uint32_t minute = ((context->head_pba - LEADIN_SECTORS) / 75) / 60;
535 byte = (minute % 10) | ((minute / 10 ) << 4);
536 } else if (context->current_sector_byte == 13) {
537 uint32_t seconds = ((context->head_pba - LEADIN_SECTORS) / 75) % 60;
538 byte = (seconds % 10) | ((seconds / 10 ) << 4);
539 } else if (context->current_sector_byte == 14) {
540 uint32_t frames = (context->head_pba - LEADIN_SECTORS) % 75;
541 byte = (frames % 10) | ((frames / 10 ) << 4);
542 } else {
543 byte = 1;
544 }
545 } else {
546 byte = fgetc(context->media->f);
547 }
548 lc8951_write_byte(cdc, cd_block_to_mclks(context->cycle), context->current_sector_byte++, byte); 512 lc8951_write_byte(cdc, cd_block_to_mclks(context->cycle), context->current_sector_byte++, byte);
549 context->last_byte_cycle = context->cycle; 513 context->last_byte_cycle = context->cycle;
550 if (context->current_sector_byte == 2352) { 514 if (context->current_sector_byte == 2352) {
551 context->current_sector_byte = -1; 515 context->current_sector_byte = -1;
552 next_byte = CYCLE_NEVER; 516 next_byte = CYCLE_NEVER;