1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
// license:BSD-3-Clause
// copyright-holders:Olivier Galibert
/*********************************************************************
formats/m20_dsk.c
Olivetti M20 floppy-disk images
Track 0/head 0 is FM, 128 byte sectors. The rest is MFM,
256 byte sectors.
In image files the sectors of track 0/sector 0 are 256 bytes
long to simplify access. Only the first half of these sectors
contain image data.
*********************************************************************/
#include "m20_dsk.h"
m20_format::m20_format()
{
}
const char *m20_format::name() const
{
return "m20";
}
const char *m20_format::description() const
{
return "M20 disk image";
}
const char *m20_format::extensions() const
{
return "img";
}
bool m20_format::supports_save() const
{
return false;
}
int m20_format::identify(io_generic *io, uint32_t form_factor)
{
if(io_generic_size(io) == 286720)
return 50;
return 0;
}
bool m20_format::load(io_generic *io, uint32_t form_factor, floppy_image *image)
{
for(int track = 0; track < 35; track++)
for(int head = 0; head < 2; head ++) {
bool mfm = track || head;
desc_pc_sector sects[16];
uint8_t sectdata[16*256];
io_generic_read(io, sectdata, 16*256*(track*2+head), 16*256);
for(int i=0; i<16; i++) {
int j = i/2 + (i & 1 ? 0 : 8);
sects[i].track = track;
sects[i].head = head;
sects[i].sector = j+1;
sects[i].size = mfm ? 1 : 0;
sects[i].actual_size = mfm ? 256 : 128;
sects[i].data = sectdata + 256*j;
sects[i].deleted = false;
sects[i].bad_crc = false;
}
if(mfm)
build_wd_track_mfm(track, head, image, 100000, 16, sects, 50, 32, 22);
else
build_wd_track_fm(track, head, image, 50000, 16, sects, 24, 16, 11);
}
return true;
}
bool m20_format::save(io_generic *io, floppy_image *image)
{
return false;
}
const floppy_format_type FLOPPY_M20_FORMAT = &floppy_image_format_creator<m20_format>;
|
