// license:BSD-3-Clause
// copyright-holders:Curt Coder
/*********************************************************************

    formats/victor9k_dsk.c

    Victor 9000 sector disk image format

*********************************************************************/

/*

    Sector format
    -------------

    Header sync
    Sector header (header ID, track ID, sector ID, and checksum)
    Gap 1
    Data Sync
    Data field (data sync, data ID, data bytes, and checksum)
    Gap 2

    Track format
    ------------

    ZONE        LOWER HEAD  UPPER HEAD  SECTORS     ROTATIONAL   RPM
    NUMBER      TRACKS      TRACKS      PER TRACK   PERIOD (MS)

    0           0-3         unused      19          237.9        252
    1           4-15        0-7         18          224.5        267
    2           16-26       8-18        17          212.2        283
    3           27-37       19-29       16          199.9        300
    4           38-48       30-40       15          187.6        320
    5           49-59       41-51       14          175.3        342
    6           60-70       52-62       13          163.0        368
    7           71-79       63-74       12          149.6        401
    8           unused      75-79       11          144.0        417

    Interleave factor 3
    cell 2.13 usec


    Boot Disc Label Format
    Track 0 Sector 0

    Byte
    Offset         Name                Description

    0              System disc ID      literally, ff,00h for a system
                                       disc

    2              Load address        paragraph   to   load   booted
                                       program at. If zero then  boot
                                       loads in high memory.

    4              Length              paragraph count to load.

    6              Entry offset        I.P.  value  for  transfer  of
                                       control.

    8              Entry segment       C.S.  value  for  transfer  of
                                       control.

    10             I.D.                disc identifier.

    18             Part number         system identifier  - displayed
                                       by early versions of boot.

    26             Sector size         byte count for sectors.

    28             Data start          first   data  sector  on  disc
                                       (absolute sectors).

    30             Boot start          first   absolute   sector   of
                                       program  for boot to  load  at
                                       'load  address'  for  'length'
                                       paragraphs.

    32             Flags               indicators:
                                            bit  meaning
                                           15-12 interleave    factor
                                                 (0-15)
                                             0   0=single sided
                                                 1=double sided

    34             Disc type           00 = CP/M
                                       01 = MS-DOS

    35             Reserved

    38             Speed table         information  for speed control
                                       proc.

    56             Zone table          high track for each zone.

    71             Sector/track        sectors  per  track  for  each
                                       zone.
*/

#include "emu.h" // osd_printf_verbose, BIT, emu_fatalerror
#include "formats/victor9k_dsk.h"

victor9k_format::victor9k_format()
{
}

const char *victor9k_format::name() const
{
	return "victor9k";
}

const char *victor9k_format::description() const
{
	return "Victor 9000 disk image";
}

const char *victor9k_format::extensions() const
{
	return "img";
}

int victor9k_format::find_size(io_generic *io, UINT32 form_factor)
{
	UINT64 size = io_generic_size(io);
	for(int i=0; formats[i].sector_count; i++) {
		const format &f = formats[i];
		if(size == (UINT32) f.sector_count*f.sector_base_size*f.head_count)
			return i;
	}
	return -1;
}

int victor9k_format::identify(io_generic *io, UINT32 form_factor)
{
	int type = find_size(io, form_factor);

	if (type != -1)
		return 50;

	return 0;
}

void victor9k_format::log_boot_sector(UINT8 *data)
{
	// System disc ID
	osd_printf_verbose("System disc: %s\n", ((data[0] == 0xff) && (data[1] == 0x00)) ? "yes" : "no");

	// Load address
	osd_printf_verbose("Load address: %04x\n", (data[1] << 8) | data[2]);

	// Length
	osd_printf_verbose("Length: %04x\n", (data[3] << 8) | data[4]);

	// Entry offset
	osd_printf_verbose("Entry offset: %04x\n", (data[5] << 8) | data[6]);

	// Entry segment
	osd_printf_verbose("Entry segment: %04x\n", (data[7] << 8) | data[8]);

	// I.D.
	//osd_printf_verbose("I.D.: %s\n", data[10]);

	// Part number
	//osd_printf_verbose("Part number: %s\n", data[18]);

	// Sector size
	osd_printf_verbose("Sector size: %04x\n", (data[25] << 8) | data[26]);

	// Data start
	osd_printf_verbose("Data start: %04x\n", (data[27] << 8) | data[28]);

	// Boot start
	osd_printf_verbose("Boot start: %04x\n", (data[29] << 8) | data[30]);

	// Flags
	osd_printf_verbose("%s sided\n", BIT(data[33], 0) ? "Double" : "Single");
	osd_printf_verbose("Interleave factor: %u\n", data[32] >> 4);

	// Disc type
	switch (data[34]) {
	case 0x00: osd_printf_verbose("Disc type: CP/M\n"); break;
	case 0x01: osd_printf_verbose("Disc type: MS-DOS\n"); break;
	default: osd_printf_verbose("Disc type: unknown\n"); break;
	}

	// Speed table
	osd_printf_verbose("Speed table:  ");
	for (int i = 38; i < 56; i++) {
		osd_printf_verbose("%02x ", data[i]);
	}
	osd_printf_verbose("\n");

	// Zone table
	osd_printf_verbose("Zone table:            ");
	for (int i = 56; i < 71; i++) {
		osd_printf_verbose("%02x ", data[i]);
	}
	osd_printf_verbose("\n");

	// Sector/track
	osd_printf_verbose("Sector/track:          ");
	for (int i = 71; i < 86; i++) {
		osd_printf_verbose("%02x ", data[i]);
	}
	osd_printf_verbose("\n");
}

floppy_image_format_t::desc_e* victor9k_format::get_sector_desc(const format &f, int &current_size, int sector_count)
{
	static floppy_image_format_t::desc_e desc[] = {
		/* 00 */ { SECTOR_INTERLEAVE_SKEW, 0, 0},
		/* 01 */ { SECTOR_LOOP_START, 0, -1 },
		/* 02 */ {   SYNC_GCR5, 9 },
		/* 03 */ {   GCR5, 0x07, 1 },
		/* 04 */ {   CRC_VICTOR_HDR_START, 1 },
		/* 05 */ {     TRACK_ID_VICTOR_GCR5 },
		/* 06 */ {     SECTOR_ID_GCR5 },
		/* 07 */ {   CRC_END, 1 },
		/* 08 */ {   CRC, 1 },
		/* 09 */ {   RAWBYTE, 0x55, 8 },
		/* 10 */ {   SYNC_GCR5, 5 },
		/* 11 */ {   GCR5, 0x08, 1 },
		/* 12 */ {   CRC_VICTOR_DATA_START, 2 },
		/* 13 */ {     SECTOR_DATA_GCR5, -1 },
		/* 14 */ {   CRC_END, 2 },
		/* 15 */ {   CRC, 2 },
		/* 16 */ {   RAWBYTE, 0x55, 8 },
		/* 17 */ { SECTOR_LOOP_END },
		/* 18 */ { RAWBYTE, 0x55, 0 },
		/* 19 */ { RAWBITS, 0x5555, 0 },
		/* 20 */ { END }
	};

	current_size = 90 + (1+1+1+1)*10 + 8*8 + 50 + (1+f.sector_base_size+2)*10 + 8*8;

	current_size *= sector_count;
	return desc;
}

void victor9k_format::build_sector_description(const format &f, UINT8 *sectdata, UINT32 sect_offs, desc_s *sectors, int sector_count) const
{
	for (int i = 0; i < sector_count; i++) {
		sectors[i].data = sectdata + sect_offs;
		sectors[i].size = f.sector_base_size;
		sectors[i].sector_id = i;

		sect_offs += sectors[i].size;
	}
}

bool victor9k_format::load(io_generic *io, UINT32 form_factor, floppy_image *image)
{
	int type = find_size(io, form_factor);
	if(type == -1)
		return false;

	const format &f = formats[type];

	UINT64 size = io_generic_size(io);
	dynamic_buffer img;
	img.resize(size);

	io_generic_read(io, &img[0], 0, size);

	log_boot_sector(&img[0]);

	int track_offset = 0;

	for (int head = 0; head < f.head_count; head++) {
		for (int track = 0; track < f.track_count; track++) {
			int current_size = 0;
			int total_size = 200000000./cell_size[speed_zone[head][track]];
			int sector_count = sectors_per_track[head][track];
			int track_size = sector_count*f.sector_base_size;

			floppy_image_format_t::desc_e *desc = get_sector_desc(f, current_size, sector_count);

			int remaining_size = total_size - current_size;
			if(remaining_size < 0)
				throw emu_fatalerror("victor9k_format: Incorrect track layout, max_size=%d, current_size=%d", total_size, current_size);

			// Fixup the end gap
			desc[18].p2 = remaining_size / 8;
			desc[19].p2 = remaining_size & 7;
			desc[19].p1 >>= remaining_size & 0x01;

			desc_s sectors[40];

			build_sector_description(f, &img[0], track_offset, sectors, sector_count);
			generate_track(desc, track, head, sectors, sector_count, total_size, image);

			track_offset += track_size;
		}
	}

	image->set_variant(f.variant);

	return true;
}

int victor9k_format::get_rpm(int head, int track)
{
	return rpm[speed_zone[head][track]];
}

int victor9k_format::get_image_offset(const format &f, int _head, int _track)
{
	int offset = 0;
	if (_head) {
		for (int track = 0; track < f.track_count; track++) {
			offset += compute_track_size(f, _head, track);
		}
	}
	for (int track = 0; track < _track; track++) {
		offset += compute_track_size(f, _head, track);
	}
	return offset;
}

int victor9k_format::compute_track_size(const format &f, int head, int track)
{
	return sectors_per_track[head][track] * f.sector_base_size;
}

const victor9k_format::format victor9k_format::formats[] = {
	{ //
		floppy_image::FF_525, floppy_image::SSDD, 1224, 80, 1, 512
	},
	{ //
		floppy_image::FF_525, floppy_image::DSDD, 2448, 80, 2, 512
	},
	{}
};

const UINT32 victor9k_format::cell_size[9] =
{
	1789, 1896, 2009, 2130, 2272, 2428, 2613, 2847, 2961
};

const int victor9k_format::sectors_per_track[2][80] =
{
	{
		19, 19, 19, 19,
		18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18,
		17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17,
		16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
		15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
		14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
		13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
		12, 12, 12, 12, 12, 12, 12, 12, 12
	},
	{
		18, 18, 18, 18, 18, 18, 18, 18,
		17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17,
		16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,
		15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
		14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
		13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
		12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
		11, 11, 11, 11, 11
	}
};

const int victor9k_format::speed_zone[2][80] =
{
	{
		0, 0, 0, 0,
		1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
		2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
		3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
		4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
		5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
		6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
		7, 7, 7, 7, 7, 7, 7, 7, 7
	},
	{
		1, 1, 1, 1, 1, 1, 1, 1,
		2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
		3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
		4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
		5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
		6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
		8, 8, 8, 8, 8
	}
};

const int victor9k_format::rpm[9] =
{
	252, 267, 283, 300, 321, 342, 368, 401, 417
};

bool victor9k_format::save(io_generic *io, floppy_image *image)
{
	const format &f = formats[0];

	for(int head=0; head < f.head_count; head++) {
		for(int track=0; track < f.track_count; track++) {
			int sector_count = sectors_per_track[head][track];
			int track_size = compute_track_size(f, head, track);
			UINT8 sectdata[40*512];
			desc_s sectors[40];
			int offset = get_image_offset(f, head, track);

			build_sector_description(f, sectdata, 0, sectors, sector_count);
			extract_sectors(image, f, sectors, track, head, sector_count);
			io_generic_write(io, sectdata, offset, track_size);
		}
	}

	return true;
}

void victor9k_format::extract_sectors(floppy_image *image, const format &f, desc_s *sdesc, int track, int head, int sector_count)
{
	UINT8 bitstream[500000/8];
	UINT8 sectdata[50000];
	desc_xs sectors[256];
	int track_size;

	// Extract the sectors
	generate_bitstream_from_track(track, head, cell_size[speed_zone[head][track]], bitstream, track_size, image);
	extract_sectors_from_bitstream_victor_gcr5(bitstream, track_size, sectors, sectdata, sizeof(sectdata));

	for(int i=0; i<sector_count; i++) {
		desc_s &ds = sdesc[i];
		desc_xs &xs = sectors[ds.sector_id];
		if(!xs.data)
			memset((void *)ds.data, 0, ds.size);
		else if(xs.size < ds.size) {
			memcpy((void *)ds.data, xs.data, xs.size);
			memset((UINT8 *)ds.data + xs.size, 0, xs.size - ds.size);
		} else
			memcpy((void *)ds.data, xs.data, ds.size);
	}
}

const floppy_format_type FLOPPY_VICTOR_9000_FORMAT = &floppy_image_format_creator<victor9k_format>;
