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/*********************************************************************
formats/dim_dsk.c
DIM disk images
*********************************************************************/
#include <string.h>
#include "dim_dsk.h"
#include "basicdsk.h"
FLOPPY_IDENTIFY(dim_dsk_identify)
{
UINT8 dim_header[16];
floppy_image_read(floppy, (UINT8*)dim_header,0xab,16);
if(strncmp((const char*)dim_header,"DIFC HEADER",11) == 0)
*vote = 100;
else
*vote = 0;
return FLOPPY_ERROR_SUCCESS;
}
FLOPPY_CONSTRUCT(dim_dsk_construct)
{
struct basicdsk_geometry geometry;
// DIM disk image header, most of this is guesswork
int tracks = 77;
int heads = 2;
int sectors = 8; // per track
int sectorlen = 1024;
int firstsector = 0x01;
UINT8 format_tmp;
int x;
UINT16 temp;
if(params)
{
// create
return FLOPPY_ERROR_UNSUPPORTED;
}
// Offset + 0 : disk format type (1 byte):
// 0 = 2HD / 2HDA (8 sector/track, 1024 bytes/sector, GAP#3 = 0x74)
// 1 = 2HS (9 sector/track, 1024 bytes/sector, GAP#3 = 0x39)
// 2 = 2HC (15 sector/track, 512 bytes/sector, GAP#3 = 0x54)
// 3 = 2HDE(68) (9 sector/track, 1024 bytes/sector, GAP#3 = 0x39)
// 9 = 2HQ (18 sector/track, 512 bytes/sector, GAP#3 = 0x54)
// 17 = N88-BASIC (26 sector/track, 256 bytes/sector, GAP#3 = 0x33)
// or (26 sector/track, 128 bytes/sector, GAP#3 = 0x1a)
//
floppy_image_read(floppy, &format_tmp,0,1);
switch(format_tmp)
{
case 0x00:
sectors = 8;
sectorlen = 1024;
break;
case 0x01:
case 0x03:
sectors = 9;
sectorlen = 1024;
break;
case 0x02:
sectors = 15;
sectorlen = 512;
break;
case 0x09:
sectors = 18;
sectorlen = 512;
break;
case 0x11:
sectors = 26;
sectorlen = 256;
break;
}
tracks = 0;
for (x=0;x<86;x++)
{
floppy_image_read(floppy,&temp,(x*2)+1,2);
if(temp == 0x0101)
tracks++;
}
// TODO: expand on this basic implementation
LOG_FORMATS("FDD: DIM image loaded - type %i, %i tracks, %i sectors per track, %i bytes per sector\n", format_tmp,tracks, sectors,sectorlen);
memset(&geometry, 0, sizeof(geometry));
geometry.heads = heads;
geometry.first_sector_id = firstsector;
geometry.sector_length = sectorlen;
geometry.tracks = tracks+1;
geometry.sectors = sectors;
geometry.offset = 0x100;
return basicdsk_construct(floppy, &geometry);
}
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