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author | 2015-11-15 02:38:06 +0000 | |
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committer | 2015-11-15 02:38:06 +0000 | |
commit | 5d004af6c92344b8a8f007b695f0203e6414e168 (patch) | |
tree | f4dee2f622739423fb34725227042371f9736cdb /src/lib/formats/fsd_dsk.cpp | |
parent | 1c79e53fbc4280c342c77a0fe3a2175eadfdfc4e (diff) |
bbc: preliminary support for FSD format.
Diffstat (limited to 'src/lib/formats/fsd_dsk.cpp')
-rw-r--r-- | src/lib/formats/fsd_dsk.cpp | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/src/lib/formats/fsd_dsk.cpp b/src/lib/formats/fsd_dsk.cpp new file mode 100644 index 00000000000..c5820c7ef66 --- /dev/null +++ b/src/lib/formats/fsd_dsk.cpp @@ -0,0 +1,180 @@ +// license:BSD-3-Clause +// copyright-holders:Nigel Barnes +/*************************************************************************** + + BBC Micro 8271 protected disk image format + + Disk image format + +***************************************************************************/ + +#include "emu.h" +#include "fsd_dsk.h" + + +/********************************************************************* + + BBC Micro 8271 protected disk image format + + Header: + ======= + Identifier: "FSD" string literal 3 bytes + Creator: 5 bytes; date of creation/author + Title: Character string (unlimited length; may contain any but null) + Title_End: 0x00 byte literal 1 byte + Num_Tr: xx 1 byte, number of tracks + + For each track + ============== + track_num: 1 byte + num_sec: 1 byte (00 == unformatted) + readable: 1 byte (00 == unreadable, ff ==readable) + + If readable: + For each sector + =============== + Track_ID: 1 byte + Head_number: 1 byte + Sector_ID: 1 byte + reported_size: 1 byte (2^{7+x}; 0 ==>128, 1 ==> 256, 2==>512, 3==>1024 etc) + real_size: 1 byte (2^{7+x}) + error_code: 1 byte (0==No Error, &20==Deleted Data; &0E = Data CRC Error) + data: <real_size> bytes + Note that error_code matches the OSWORD &7F result byte + + If unreadable: + Track_ID: 1 byte + Head_number: 1 byte + Sector_ID: 1 byte + reported_size: 1 byte + + Decoding of the "creator" 5 byte field: + ======================================= + (byte1 byte2 byte3 byte4 byte5) + + Date_DD = (byte1 AND &F8)/8 + Date_MM = (byte3 AND &0F) + Date_YYYY = (byte1 AND &07)*256+byte2 + Creator_ID = (byte3 AND &F0)/16 + Release_num = ((byte5 AND &C0)/64)*256 + byte4 + +*********************************************************************/ + +fsd_format::fsd_format() +{ +} + +const char *fsd_format::name() const +{ + return "fsd"; +} + +const char *fsd_format::description() const +{ + return "BBC Micro 8271 protected disk image"; +} + +const char *fsd_format::extensions() const +{ + return "fsd"; +} + +bool fsd_format::supports_save() const +{ + return false; +} + +int fsd_format::identify(io_generic *io, UINT32 form_factor) +{ + UINT8 h[3]; + + io_generic_read(io, h, 0, 3); + if (memcmp(h, "FSD", 3) == 0) { + return 100; + } + return 0; +} + +bool fsd_format::load(io_generic *io, UINT32 form_factor, floppy_image *image) +{ + UINT64 size = io_generic_size(io); + dynamic_buffer img(size); + io_generic_read(io, &img[0], 0, size); + + UINT64 pos; + std::string title; + for(pos=8; pos < size && img[pos] != NULL; pos++) + title += char(img[pos]); + pos++; + + if(pos >= size) + return false; + + //popmessage("Loading image of '%s'\n", title); + + desc_pc_sector sects[10]; + UINT8 total_tracks = img[pos++]; + UINT8 tnum, hnum, snum, ssize, error; + + hnum = 0; + //osd_printf_verbose("%d Tracks\n", total_tracks+1); + //osd_printf_verbose("Tr.# No.S Sec.# Tr.ID Head# SecID IDsiz REsiz Error\n"); + for(int curr_track=0; curr_track <= total_tracks; curr_track++) + { + UINT8 track = img[pos++]; + UINT8 spt = img[pos++]; + //osd_printf_verbose("%x %x\n", track, spt); + if (spt > 0) // formatted + { + UINT8 readable = img[pos++]; + for (int i = 0; i < spt; i++) + { + tnum = img[pos++]; // logical track + hnum = img[pos++]; // head number + snum = img[pos++]; // logical sector + ssize = img[pos++]; // reported size + sects[i].track = tnum; + sects[i].head = hnum; + sects[i].sector = snum; + sects[i].size = ssize; + if (readable == 0xff) + { + sects[i].actual_size = 1 << (img[pos++] + 7); + error = img[pos++]; + sects[i].deleted = (error & 0x20) == 0x20; + sects[i].bad_crc = (error & 0x0e) == 0x0e; + sects[i].data = &img[pos]; + pos += sects[i].actual_size; + //osd_printf_verbose("Read %x %x %x %x %x %x %x\n", i, sects[i].track, sects[i].head, sects[i].sector, sects[i].size, sects[i].actual_size, error); + } + else + { + throw emu_fatalerror("fsd_format: Unsupported unreadable sector on track %d sector %d head %d", track, i, hnum); + + // Unreadable sectors not supported!! + //sects[i].track = track; + //sects[i].head = 0; + //sects[i].sector = i; + //sects[i].size = 0; + //sects[i].actual_size = 0; + //sects[i].deleted = false; + //sects[i].bad_crc = false; + //sects[i].data = NULL; + //osd_printf_verbose("Unread %x %x %x %x %x %x %x\n", i, sects[i].track, sects[i].head, sects[i].sector, sects[i].size, sects[i].actual_size, 0); + } + } + } + else // unformatted + { + sects[0].track = curr_track; + sects[0].head = hnum; + sects[0].sector = 0; + sects[0].size = 0; + //osd_printf_verbose("Unform %x %x %x %x %x %x %x\n", 0, sects[0].track, sects[0].head, sects[0].sector, sects[0].size, sects[0].actual_size, 0); + } + build_wd_track_fm(curr_track, hnum, image, 50000, spt, sects, 10, 40, 10); + } + return true; +} + +const floppy_format_type FLOPPY_FSD_FORMAT = &floppy_image_format_creator<fsd_format>; |