diff options
Diffstat (limited to 'src/lib/formats/nabupc_dsk.cpp')
-rw-r--r-- | src/lib/formats/nabupc_dsk.cpp | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/src/lib/formats/nabupc_dsk.cpp b/src/lib/formats/nabupc_dsk.cpp new file mode 100644 index 00000000000..00205c1e560 --- /dev/null +++ b/src/lib/formats/nabupc_dsk.cpp @@ -0,0 +1,228 @@ +// license:BSD-3-Clause +// copyright-holders:Brian Johnson +/********************************************************************* + + formats/nabupc_dsk.cpp + + NABU PC floppy-disk images + + Disk Layouts: + 200k - 1 head , 40 tracks, 5 1024 byte sectors per track + 400k - 2 heads, 40 tracks, 5 1024 byte sectors per track + 800k - 2 heads, 80 tracks, 5 1024 byte sectors per track +*********************************************************************/ + +#include "nabupc_dsk.h" + +#include "imageutl.h" +#include "ioprocs.h" +#include "strformat.h" + + +const nabupc_format::format nabupc_format::formats[] = +{ + { // 200k 40 track single sided double density (nabu) + floppy_image::FF_525, floppy_image::SSDD, + 40, 1, 32, 22, 80, + {0x00, 0x28, 0x00, 0x03, 0x07, 0x00, 0xc2, 0x00, 0x5f, 0x00, 0xe0, 0x00, 0x00, 0x18, 0x01, 0x00, 0x03, 0x07} + }, + { // 400k 40 track double sided double density (nabu) + floppy_image::FF_525, floppy_image::DSDD, + 40, 2, 32, 22, 80, + {0x01, 0x28, 0x00, 0x04, 0x0f, 0x01, 0xc4, 0x00, 0xbf, 0x00, 0xe0, 0x00, 0x00, 0x30, 0x01, 0x00, 0x03, 0x07} + }, + { // 800k 80 track double sided double density (nabu) + floppy_image::FF_35, floppy_image::DSDD, + 80, 2, 32, 22, 80, + {0x02, 0x28, 0x00, 0x04, 0x0f, 0x00, 0x8c, 0x01, 0x7f, 0x01, 0xfc, 0x00, 0x00, 0x61, 0x01, 0x00, 0x03, 0x07} + }, + {} +}; + +nabupc_format::nabupc_format() +{ +} + +int nabupc_format::find_format(util::random_read &io, uint32_t form_factor, const std::vector<uint32_t> &variants) const +{ + uint64_t size; + if (io.length(size)) { + return -1; + } + + for (int i = 0; formats[i].form_factor; i++) { + const format &f = formats[i]; + + if (form_factor != floppy_image::FF_UNKNOWN && form_factor != f.form_factor) { + continue; + } + if (!variants.empty() && !has_variant(variants, f.variant)) { + continue; + } + if (size == (uint64_t)sector_size * sector_count * f.track_count * f.head_count) { + LOG_FORMATS("nabupc: Found nabupc disk: %d\n", i); + return i; + } + LOG_FORMATS("nabupc: no match\n"); + } + return -1; +} + +int nabupc_format::identify(util::random_read &io, uint32_t form_factor, const std::vector<uint32_t> &variants) const +{ + + int const format = find_format(io, form_factor, variants); + + if (format == -1) { + return 0; + } + + return FIFID_SIZE; +} + +void nabupc_format::build_nabu_track_mfm(int track, int head, floppy_image &image, int cell_count, int sector_count, const desc_pc_sector *sects, int gap_3, int gap_1, int gap_2, const uint8_t *dpb) +{ + std::vector<uint32_t> track_data; + + if (dpb[1] != 0 && track == 0 && head == 0) { + for (int i = 0; i < 2; i++) raw_w(track_data, 16, 0x4489); + raw_w(track_data, 16, 0x1054); // 4e + for (int i = 0; i < 11; i++) mfm_w(track_data, 8, 0x4e); + mfm_w(track_data, 8, 0x19); + mfm_w(track_data, 8, 0x0F); + mfm_w(track_data, 8, 0x2D); + mfm_w(track_data, 8, 0x1A); + for (int i = 0; i < 18; i++) mfm_w(track_data, 8, dpb[i]); + } + + for (int i = 0; i < gap_1; i++) mfm_w(track_data, 8, 0x4e); + + int total_size = 0; + for (int i = 0; i < sector_count; i++) total_size += sects[i].actual_size; + + int etpos = int(track_data.size()) + (sector_count * (12 + 3 + 5 + 2 + gap_2 + 12 + 3 + 1+ 2) + total_size) * 16; + + if (etpos > cell_count) { + throw std::invalid_argument(util::string_format("Incorrect layout on track %d head %d, expected_size=%d, current_size=%d", track, head, cell_count, etpos)); + } + + if (etpos + gap_3 * 16 * (sector_count - 1) > cell_count) { + gap_3 = (cell_count - etpos) / 16 / (sector_count - 1); + } + + // Build the track + for (int i = 0; i < sector_count; i++) { + uint16_t crc; + // sync and IDAM and gap 2 + for (int j = 0; j < 12; j++) mfm_w(track_data, 8, 0x00); + unsigned int cpos = track_data.size(); + for (int j = 0; j < 3; j++) raw_w(track_data, 16, 0x4489); + mfm_w(track_data, 8, 0xfe); + mfm_w(track_data, 8, sects[i].track); + mfm_w(track_data, 8, sects[i].head); + mfm_w(track_data, 8, sects[i].sector); + mfm_w(track_data, 8, sects[i].size); + crc = calc_crc_ccitt(track_data, cpos, track_data.size()); + mfm_w(track_data, 16, crc); + for (int j = 0; j < gap_2; j++) mfm_w(track_data, 8, 0x4e); + + if (!sects[i].data) { + for (int j = 0; j < 12 + 4 + sects[i].actual_size + 2 + (i != sector_count - 1 ? gap_3 : 0); j++) mfm_w(track_data, 8, 0x4e); + } else { + // sync, DAM, data and gap 3 + for (int j = 0; j < 12; j++) mfm_w(track_data, 8, 0x00); + cpos = track_data.size(); + for (int j = 0; j < 3; j++) raw_w(track_data, 16, 0x4489); + mfm_w(track_data, 8, sects[i].deleted ? 0xf8 : 0xfb); + for (int j = 0; j < sects[i].actual_size; j++) mfm_w(track_data, 8, sects[i].data[j]); + crc = calc_crc_ccitt(track_data, cpos, track_data.size()); + if (sects[i].bad_crc) { + crc = 0xffff^crc; + } + mfm_w(track_data, 16, crc); + if (i != sector_count - 1) { + for (int j = 0; j < gap_3; j++) mfm_w(track_data, 8, 0x4e); + } + } + } + + // Gap 4b + + while (int(track_data.size()) < cell_count - 15) mfm_w(track_data, 8, 0x4e); + raw_w(track_data, cell_count - int(track_data.size()), 0x9254 >> (16 + int(track_data.size()) - cell_count)); + + generate_track_from_levels(track, head, track_data, 0, image); +} + +bool nabupc_format::load(util::random_read &io, uint32_t form_factor, const std::vector<uint32_t> &variants, floppy_image &image) const +{ + int const type = find_format(io, form_factor, variants); + + if (type == -1) { + return false; + } + + const format &f = formats[type]; + + for (int track = 0; track < f.track_count; track++) { + for (int head = 0; head < f.head_count; head++) { + desc_pc_sector sects[sector_count]; + uint8_t sectdata[sector_count * sector_size]; + /*auto const [err, actual] =*/ read_at(io, (track * f.head_count + head) * sector_count * sector_size, sectdata, sector_count * sector_size); // FIXME: check for errors and premature EOF + for (int i = 0; i < sector_count; i++) { + sects[i].track = track; + sects[i].head = head; + sects[i].sector = i + 1; + sects[i].size = 3; + sects[i].actual_size = sector_size; + sects[i].data = sectdata + sector_size * i; + sects[i].deleted = false; + sects[i].bad_crc = false; + } + build_nabu_track_mfm(track, head, image, 100000, sector_count, sects, f.gap_3, f.gap_1, f.gap_2, f.dpb); + } + } + return true; +} + +bool nabupc_format::save(util::random_read_write &io, const std::vector<uint32_t> &variants, const floppy_image &image) const +{ + + int heads, tracks; + image.get_actual_geometry(tracks, heads); + for (int track = 0; track < tracks; track++) { + for (int head = 0; head < heads; head++) { + uint64_t file_offset = (track * heads + head) * sector_count * sector_size; + auto bitstream = generate_bitstream_from_track(track, head, 2000, image); + auto sectors = extract_sectors_from_bitstream_mfm_pc(bitstream); + for (int i = 0; i < sector_count; i++) { + /*auto const [err, actual] =*/ write_at(io, file_offset, sectors[i + 1].data(), sector_size); // FIXME: check for errors + file_offset += sector_size; + } + } + } + + return true; +} + +const char *nabupc_format::name() const noexcept +{ + return "nabupc"; +} + +const char *nabupc_format::description() const noexcept +{ + return "NABU PC CP/M Disk Image"; +} + +const char *nabupc_format::extensions() const noexcept +{ + return "img,dsk"; +} + +bool nabupc_format::supports_save() const noexcept +{ + return true; +} + +const nabupc_format FLOPPY_NABUPC_FORMAT; |