mame/src/lib/formats/apridisk.cpp
2015-11-08 12:56:12 +01:00

149 lines
3.7 KiB
C++

// license:GPL-2.0+
// copyright-holders:Dirk Best
/***************************************************************************
APRIDISK
Disk image format for the ACT Apricot
***************************************************************************/
#include "emu.h"
#include "imageutl.h"
#include "apridisk.h"
apridisk_format::apridisk_format()
{
}
const char *apridisk_format::name() const
{
return "apridisk";
}
const char *apridisk_format::description() const
{
return "APRIDISK disk image";
}
const char *apridisk_format::extensions() const
{
return "dsk";
}
int apridisk_format::identify(io_generic *io, UINT32 form_factor)
{
UINT8 header[APR_HEADER_SIZE];
io_generic_read(io, header, 0, APR_HEADER_SIZE);
const char magic[] = "ACT Apricot disk image\x1a\x04";
if (memcmp(header, magic, sizeof(magic) - 1) == 0)
return 100;
else
return 0;
}
bool apridisk_format::load(io_generic *io, UINT32 form_factor, floppy_image *image)
{
desc_pc_sector sectors[80][2][18];
UINT8 sector_data[MAX_SECTORS * SECTOR_SIZE];
UINT8 *data_ptr = sector_data;
int track_count = 0, head_count = 0, sector_count = 0;
UINT64 file_size = io_generic_size(io);
UINT64 file_offset = APR_HEADER_SIZE;
while (file_offset < file_size)
{
// read sector header
UINT8 sector_header[16];
io_generic_read(io, sector_header, file_offset, 16);
UINT32 type = pick_integer_le(&sector_header, 0, 4);
UINT16 compression = pick_integer_le(&sector_header, 4, 2);
UINT16 header_size = pick_integer_le(&sector_header, 6, 2);
UINT32 data_size = pick_integer_le(&sector_header, 8, 4);
file_offset += header_size;
switch (type)
{
case APR_SECTOR:
UINT8 head = pick_integer_le(&sector_header, 12, 1);
UINT8 sector = pick_integer_le(&sector_header, 13, 1);
UINT8 track = (UINT8) pick_integer_le(&sector_header, 14, 2);
track_count = MAX(track_count, track);
head_count = MAX(head_count, head);
sector_count = MAX(sector_count, sector);
// build sector info
sectors[track][head][sector - 1].head = head;
sectors[track][head][sector - 1].sector = sector;
sectors[track][head][sector - 1].track = track;
sectors[track][head][sector - 1].size = SECTOR_SIZE >> 8;
sectors[track][head][sector - 1].actual_size = SECTOR_SIZE;
sectors[track][head][sector - 1].deleted = false;
sectors[track][head][sector - 1].bad_crc = false;
// read sector data
switch (compression)
{
case APR_COMPRESSED:
{
UINT8 comp[3];
io_generic_read(io, comp, file_offset, 3);
UINT16 length = pick_integer_le(comp, 0, 2);
if (length != SECTOR_SIZE)
fatalerror("apridisk_format: Invalid compression length %04x\n", length);
memset(data_ptr, comp[2], SECTOR_SIZE);
}
break;
case APR_UNCOMPRESSED:
io_generic_read(io, data_ptr, file_offset, SECTOR_SIZE);
break;
default:
fatalerror("apridisk_format: Invalid compression %04x\n", compression);
}
sectors[track][head][sector - 1].data = data_ptr;
data_ptr += SECTOR_SIZE;
break;
}
file_offset += data_size;
}
// track/head index are zero-based, so increase the final count by 1
track_count++;
head_count++;
int cell_count = (sector_count == 18 ? 200000 : 100000);
// now build our final track info
for (int track = 0; track < track_count; track++)
for (int head = 0; head < head_count; head++)
build_pc_track_mfm(track, head, image, cell_count, sector_count, sectors[track][head], 84, 80, 50, 22);
return true;
}
bool apridisk_format::save(io_generic *io, floppy_image *image)
{
return false;
}
bool apridisk_format::supports_save() const
{
return false;
}
const floppy_format_type FLOPPY_APRIDISK_FORMAT = &floppy_image_format_creator<apridisk_format>;