// license:BSD-3-Clause
// copyright-holders:Barry Rodewald
/*
* flex_dsk.c - FLEX compatible disk images
*
* Created on: 24/06/2014
*
* TODO This format does not yet handle double density disks with a single
* density track 0. FLEX DSK files are generally 'fixed' to have a consistent
* number of sectors per track which makes them easier to work with and gains
* more storage space, and tools and emulators generally only work with these
* formats. For now use single density disks, or patch the ROM to load the
* boot sector(s) in double density and patch the drivers to use double
* density on track zero. Drivers developed for emulators commonly have other
* issues and need work anyway.
*/
#include "flex_dsk.h"
#include "formats/imageutl.h"
flex_format::flex_format() : wd177x_format(formats)
{
}
const char *flex_format::name() const
{
return "flex";
}
const char *flex_format::description() const
{
return "FLEX compatible disk image";
}
const char *flex_format::extensions() const
{
return "dsk";
}
int flex_format::identify(io_generic *io, uint32_t form_factor)
{
int type = find_size(io, form_factor);
if (type != -1)
return 75;
return 0;
}
int flex_format::find_size(io_generic *io, uint32_t form_factor)
{
uint64_t size = io_generic_size(io);
uint8_t boot0[256], boot1[256];
// Look at the boot sector.
// Density, sides, link??
io_generic_read(io, &boot0, 256 * 0, sizeof(boot0));
io_generic_read(io, &boot1, 256 * 1, sizeof(boot1));
// Look at the system information sector.
io_generic_read(io, &info, 256 * 2, sizeof(struct sysinfo_sector));
LOG_FORMATS("FLEX floppy dsk size %d %d %d\n", (uint32_t)size, (uint32_t)size / 256, (uint32_t)size % 256);
LOG_FORMATS(" boot0:");
for (int i = 0; i < 16; i++) {
LOG_FORMATS(" %02x", boot0[i]);
}
LOG_FORMATS("\n");
LOG_FORMATS(" boot1:");
for (int i = 0; i < 16; i++) {
LOG_FORMATS(" %02x", boot1[i]);
}
LOG_FORMATS("\n");
// Check that the 'unused' area is actually unused.
LOG_FORMATS(" unused1:");
for (int i = 0; i < sizeof(info.unused1); i++) {
LOG_FORMATS(" %02x", info.unused1[i]);
}
LOG_FORMATS("\n");
LOG_FORMATS(" disk_name: \"");
for (int i = 0; i < sizeof(info.disk_name); i++) {
uint8_t ch = info.disk_name[i];
if (ch < 0x20 || ch > 0x7f) {
LOG_FORMATS("[%02x]", ch);
} else {
LOG_FORMATS("%c", ch);
}
}
if (info.disk_ext[0] || info.disk_ext[1] || info.disk_ext[2]) {
LOG_FORMATS(".");
for (int i = 0; i < sizeof(info.disk_ext); i++) {
uint8_t ch = info.disk_ext[i];
if (ch < 0x20 || ch > 0x7f) {
LOG_FORMATS("[%02x]", ch);
} else {
LOG_FORMATS("%c", ch);
}
}
}
LOG_FORMATS("\"\n");
LOG_FORMATS(" fc_start_trk %d, fc_start_sec %d\n", info.fc_start_trk, info.fc_start_sec);
LOG_FORMATS(" fc_end_trk: %d, fc_end_sec: %d\n", info.fc_end_trk, info.fc_end_sec);
LOG_FORMATS(" free: %02x %02x\n", info.free[0], info.free[0]);
LOG_FORMATS(" month %d day %d year %d\n", info.month, info.day, info.year);
LOG_FORMATS(" last_trk %d, last_sec %d\n", info.last_trk, info.last_sec);
LOG_FORMATS(" unused2:");
for (int i = 0; i < 16; i++) {
LOG_FORMATS(" %02x", info.unused2[i]);
}
LOG_FORMATS("\n");
#if 0
// Check that the first 'unused' area is zero filled.
// Unfortunately an occasional dsk image has non-zero values here.
for (int i = 0; i < sizeof(info.unused1); i++)
if (info.unused1[i] != 0) return -1;
#endif
// Consistency checks.
if (info.fc_start_trk > info.last_trk || info.fc_end_trk > info.last_trk)
return -1;
if (info.fc_start_sec > info.last_sec || info.fc_end_sec > info.last_sec)
return -1;
if (info.month < 1 || info.month > 12 || info.day < 1 || info.day > 31)
return -1;
// FLEX sector numbers start at one generally, however the 6800 ROM
// boot loaders load the boot code from track zero, side zero,
// starting at sector zero. The boot code attempts to read multiple
// sectors and a gap in the sector numbering appears to be used to
// terminate the sequence. So if only one sector is to be loaded then
// the sector numbering is 0, 2, 3, .... If two sectors are to be
// loaded then the sector numbering is 0, 1, 3, 4 ... The boot loaders
// for 6809 FLEX systems appear to load from sector one so do not have
// this inconsistency to handle.
boot0_sector_id = 1;
boot1_sector_id = 2;
// This floppy format uses a strategy of looking for 6800 boot code to
// set the numbering of the first two sectors. If this is shown to not
// be practical in some common cases then a separate format variant
// might be needed.
if (boot0[0] == 0x8e && boot0[3] == 0x20)
{
// Found a 6800 stack load and branch, looks like a 6800 boot sector.
boot0_sector_id = 0;
// Look for a link to the next sector, normal usage.
if (boot1[0] != 0 || boot1[1] != 3)
{
// If not then assume it is a boot sector.
boot1_sector_id = 1;
}
}
LOG_FORMATS(" boot sector ids: %d %d\n", boot0_sector_id, boot1_sector_id);
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(size != (uint64_t)compute_track_size(f) * f.track_count * f.head_count)
continue;
// Check consistency with the sysinfo record sector.
if (f.track_count != info.last_trk + 1)
continue;
if (f.sector_count * f.head_count != info.last_sec)
continue;
return i;
}
return -1;
}
// FLEX numbers sectors on the second side of a track continuing from the
// first side which is a variation not handled by the generic code.
//
// FLEX generally numbers sectors starting at 1, however the 6800 boot sectors
// are numbers starting at zero.
//
void flex_format::build_sector_description(const format &f, uint8_t *sectdata, desc_s *sectors, int track, int head) const
{
if(f.sector_base_id == -1) {
for(int i=0; i<f.sector_count; i++) {
int cur_offset = 0;
for(int j=0; j<f.sector_count; j++)
if(f.per_sector_id[j] < f.per_sector_id[i])
cur_offset += f.sector_base_size ? f.sector_base_size : f.per_sector_size[j];
sectors[i].data = sectdata + cur_offset;
sectors[i].size = f.sector_base_size ? f.sector_base_size : f.per_sector_size[i];
uint8_t sector_id = f.per_sector_id[i];
if (track == 0 && head == 0 && sector_id <= 2) {
if (sector_id == 0)
sector_id = boot0_sector_id;
else
sector_id = boot1_sector_id;
}
sectors[i].sector_id = f.sector_count * head + sector_id;
}
} else {
int cur_offset = 0;
for(int i=0; i<f.sector_count; i++) {
sectors[i].data = sectdata + cur_offset;
sectors[i].size = f.sector_base_size ? f.sector_base_size : f.per_sector_size[i];
cur_offset += sectors[i].size;
uint8_t sector_id = i + f.sector_base_id;
if (track == 0 && head == 0 && i < 2) {
if (i == 0)
sector_id = boot0_sector_id;
else
sector_id = boot1_sector_id;
}
sectors[i].sector_id = f.sector_count * head + sector_id;
}
}
}
// For FLEX just use track 1 rather than the generic code that looks a track
// 0. This is enough to avoid the odd sector numbering for the boot sectors,
// while following the generic code.
void flex_format::check_compatibility(floppy_image *image, std::vector<int> &candidates)
{
uint8_t bitstream[500000/8];
uint8_t sectdata[50000];
desc_xs sectors[256];
int track_size;
// Extract the sectors
generate_bitstream_from_track(1, 0, formats[candidates[0]].cell_size, bitstream, track_size, image);
switch (formats[candidates[0]].encoding)
{
case floppy_image::FM:
extract_sectors_from_bitstream_fm_pc(bitstream, track_size, sectors, sectdata, sizeof(sectdata));
break;
case floppy_image::MFM:
extract_sectors_from_bitstream_mfm_pc(bitstream, track_size, sectors, sectdata, sizeof(sectdata));
break;
}
// Check compatibility with every candidate, copy in-place
int *ok_cands = &candidates[0];
for(unsigned int i=0; i != candidates.size(); i++) {
const format &f = formats[candidates[i]];
int ns = 0;
for(int j=0; j<256; j++)
if(sectors[j].data) {
int sid;
if(f.sector_base_id == -1) {
for(sid=0; sid < f.sector_count; sid++)
if(f.per_sector_id[sid] == j)
break;
} else
sid = j - f.sector_base_id;
if(sid < 0 || sid > f.sector_count)
goto fail;
if(f.sector_base_size) {
if(sectors[j].size != f.sector_base_size)
goto fail;
} else {
if(sectors[j].size != f.per_sector_size[sid])
goto fail;
}
ns++;
}
if(ns == f.sector_count)
*ok_cands++ = candidates[i];
fail:
;
}
candidates.resize(ok_cands - &candidates[0]);
}
const flex_format::format flex_format::formats[] = {
{ // 87.5K 5 1/4 inch single density - gaps unverified
floppy_image::FF_525, floppy_image::SSSD, floppy_image::FM,
4000, 10, 35, 1, 256, {}, 1, {}, 40, 16, 11
},
{ // 100K 5 1/4 inch single density - gaps unverified
floppy_image::FF_525, floppy_image::SSSD, floppy_image::FM,
4000, 10, 40, 1, 256, {}, 1, {}, 40, 16, 11
},
{ // 200K 5 1/4 inch single density - gaps unverified
floppy_image::FF_525, floppy_image::SSSD, floppy_image::FM,
4000, 10, 80, 1, 256, {}, 1, {}, 40, 16, 11
},
{ // 175K 5 1/4 inch single density - gaps unverified
floppy_image::FF_525, floppy_image::DSSD, floppy_image::FM,
4000, 10, 35, 2, 256, {}, 1, {}, 40, 16, 11
},
{ // 200K 5 1/4 inch single density - gaps unverified
floppy_image::FF_525, floppy_image::DSSD, floppy_image::FM,
4000, 10, 40, 2, 256, {}, 1, {}, 40, 16, 11
},
{ // 400K 5 1/4 inch single density - gaps unverified
floppy_image::FF_525, floppy_image::DSSD, floppy_image::FM,
4000, 10, 80, 2, 256, {}, 1, {}, 40, 16, 11
},
{ // 320K 5 1/4 inch double density - gaps unverified
floppy_image::FF_525, floppy_image::SSDD, floppy_image::MFM,
2000, 18, 40, 1, 256, {}, 1, {}, 80, 22, 24
},
{ // 320K 5 1/4 inch double density - gaps unverified
floppy_image::FF_525, floppy_image::DSDD, floppy_image::MFM,
2000, 18, 40, 2, 256, {}, 1, {}, 80, 22, 24
},
{ // 360K 5 1/4 inch quad density - gaps unverified
floppy_image::FF_525, floppy_image::SSQD, floppy_image::MFM,
2000, 18, 80, 1, 256, {}, 1, {}, 80, 22, 24
},
{ // 720K 5 1/4 inch quad density - gaps unverified
floppy_image::FF_525, floppy_image::DSQD, floppy_image::MFM,
2000, 18, 80, 2, 256, {}, 1, {}, 80, 22, 24
},
{ // 288.75K 8 inch single density - gaps unverified
floppy_image::FF_8, floppy_image::SSSD, floppy_image::FM,
2000, 15, 77, 1, 256, {}, 1, {}, 40, 12, 12
},
{ // 577.5K 8 inch single density - gaps unverified
floppy_image::FF_8, floppy_image::DSSD, floppy_image::FM,
2000, 15, 77, 2, 256, {}, 1, {}, 40, 12, 12
},
{ // 500.5K 8 inch double density - gaps unverified
floppy_image::FF_8, floppy_image::SSDD, floppy_image::MFM,
1000, 26, 77, 1, 256, {}, 1, {}, 80, 22, 24
},
{ // 1001K 8 inch double density - gaps unverified
floppy_image::FF_8, floppy_image::DSDD, floppy_image::MFM,
1000, 26, 77, 2, 256, {}, 1, {}, 80, 22, 24
},
{ /* 1440K 3 1/2 inch high density */
floppy_image::FF_35, floppy_image::DSHD, floppy_image::MFM,
1000, 36, 80, 2, 256, {}, 1, {}, 80, 22, 24
},
{}
};
const floppy_format_type FLOPPY_FLEX_FORMAT = &floppy_image_format_creator<flex_format>;