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// license:BSD-3-Clause
// copyright-holders:Olivier Galibert
#include "hxcmfm_dsk.h"
#include "ioprocs.h"
#include <cstring>
#define MFM_FORMAT_HEADER "HXCMFM"
#pragma pack(1)
struct MFMIMG
{
uint8_t headername[7];
uint16_t number_of_track;
uint8_t number_of_side;
uint16_t floppyRPM;
uint16_t floppyBitRate;
uint8_t floppyiftype;
uint32_t mfmtracklistoffset;
};
struct MFMTRACKIMG
{
uint16_t track_number;
uint8_t side_number;
uint32_t mfmtracksize;
uint32_t mfmtrackoffset;
};
#pragma pack()
mfm_format::mfm_format() : floppy_image_format_t()
{
}
const char *mfm_format::name() const
{
return "mfm";
}
const char *mfm_format::description() const
{
return "HxCFloppyEmulator floppy disk image";
}
const char *mfm_format::extensions() const
{
return "mfm";
}
bool mfm_format::supports_save() const
{
return true;
}
int mfm_format::identify(util::random_read &io, uint32_t form_factor, const std::vector<uint32_t> &variants) const
{
uint8_t header[7];
size_t actual;
io.read_at(0, &header, sizeof(header), actual);
if ( memcmp( header, MFM_FORMAT_HEADER, 6 ) ==0) {
return FIFID_SIGN;
}
return 0;
}
bool mfm_format::load(util::random_read &io, uint32_t form_factor, const std::vector<uint32_t> &variants, floppy_image *image) const
{
size_t actual;
MFMIMG header;
MFMTRACKIMG trackdesc;
// read header
io.read_at(0, &header, sizeof(header), actual);
int drivecyl, driveheads;
image->get_maximal_geometry(drivecyl, driveheads);
bool skip_odd = (drivecyl < 50 && header.number_of_track >= 80);
int counter = 0;
std::vector<uint8_t> trackbuf;
for(int track=0; track < header.number_of_track; track++) {
for(int side=0; side < header.number_of_side; side++) {
if (!skip_odd || track%2 == 0) {
// read location of
io.read_at((header.mfmtracklistoffset)+( counter *sizeof(trackdesc)), &trackdesc, sizeof(trackdesc), actual);
trackbuf.resize(trackdesc.mfmtracksize);
// actual data read
io.read_at(trackdesc.mfmtrackoffset, &trackbuf[0], trackdesc.mfmtracksize, actual);
if (skip_odd) {
generate_track_from_bitstream(track/2, side, &trackbuf[0], trackdesc.mfmtracksize*8, image);
}
else {
generate_track_from_bitstream(track, side, &trackbuf[0], trackdesc.mfmtracksize*8, image);
}
}
counter++;
}
}
image->set_variant(floppy_image::DSDD);
return true;
}
bool mfm_format::save(util::random_read_write &io, const std::vector<uint32_t> &variants, floppy_image *image) const
{
// TODO: HD support
size_t actual;
MFMIMG header;
int track_count, head_count;
image->get_actual_geometry(track_count, head_count);
memcpy(&header.headername, MFM_FORMAT_HEADER, 7);
header.number_of_track = track_count;
header.number_of_side = head_count;
header.floppyRPM = 0;
header.floppyBitRate = 250;
header.floppyiftype = 4;
header.mfmtracklistoffset = sizeof(MFMIMG);
io.write_at(0, &header, sizeof(MFMIMG), actual);
int tpos = sizeof(MFMIMG);
int dpos = tpos + track_count*head_count*sizeof(MFMTRACKIMG);
for(int track=0; track < track_count; track++) {
for(int side=0; side < head_count; side++) {
auto trackbuf = generate_bitstream_from_track(track, side, 2000, image);
std::vector<uint8_t> packed((trackbuf.size() + 7) >> 3, 0);
for(uint32_t i = 0; i != trackbuf.size(); i++)
if(trackbuf[i])
packed[i >> 3] |= 0x80 >> (i & 7);
MFMTRACKIMG trackdesc;
trackdesc.track_number = track;
trackdesc.side_number = side;
trackdesc.mfmtracksize = packed.size();
trackdesc.mfmtrackoffset = dpos;
io.write_at(tpos, &trackdesc, sizeof(MFMTRACKIMG), actual);
io.write_at(dpos, packed.data(), packed.size(), actual);
tpos += sizeof(MFMTRACKIMG);
dpos += packed.size();
}
}
return true;
}
const mfm_format FLOPPY_MFM_FORMAT;
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