1 // license:LGPL-2.1+
2 // copyright-holders:Michael Zapf
3 /****************************************************************************
4
5 Hard disk support
6 See mfm_hd.c for documentation
7
8 Michael Zapf
9
10 February 2012: Rewritten as class
11
12 *****************************************************************************/
13 #ifndef MAME_FORMATS_MFM_HD_H
14 #define MAME_FORMATS_MFM_HD_H
15
16 #pragma once
17
18 #include "chd.h"
19
20 const chd_metadata_tag MFM_HARD_DISK_METADATA_TAG = CHD_MAKE_TAG('G','D','D','I');
21
22 extern const char *MFMHD_REC_METADATA_FORMAT;
23 extern const char *MFMHD_GAP_METADATA_FORMAT;
24
25 /*
26 Determine how data are passed from the hard disk to the controller. We
27 allow for different degrees of hardware emulation.
28 */
29 enum mfmhd_enc_t
30 {
31 MFM_BITS, // One bit at a time
32 MFM_BYTE, // One data byte with interleaved clock bits
33 SEPARATED, // 8 clock bits (most sig byte), one data byte (least sig byte)
34 SEPARATED_SIMPLE // MSB: 00/FF (standard / mark) clock, LSB: one data byte
35 };
36
37 class mfmhd_image_format_t;
38
39 // Pointer to its alloc function
40 typedef mfmhd_image_format_t *(*mfmhd_format_type)();
41
42 template<class _FormatClass>
mfmhd_image_format_creator()43 mfmhd_image_format_t *mfmhd_image_format_creator()
44 {
45 return new _FormatClass();
46 }
47
48 /*
49 Parameters for the track layout
50 */
51 class mfmhd_layout_params
52 {
53 public:
54 // Geometry params. These are fixed for the device. However, sector sizes
55 // could be changed, but we do not support this (yet). These are defined
56 // in the CHD and must match those of the device. They are stored by the GDDD tag.
57 // The encoding is not stored in the CHD but is also supposed to be immutable.
58 int cylinders;
59 int heads;
60 int sectors_per_track;
61 int sector_size;
62 mfmhd_enc_t encoding;
63
64 // Parameters like interleave, precompensation, write current can be changed
65 // on every write operation. They are stored by the GDDI tag (first record).
66 int interleave;
67 int cylskew;
68 int headskew;
69 int write_precomp_cylinder; // if -1, no wpcom on the disks
70 int reduced_wcurr_cylinder; // if -1, no rwc on the disks
71
72 // Parameters for the track layout that are supposed to be the same for
73 // all tracks and that do not change (until the next reformat).
74 // Also, they do not have any influence on the CHD file.
75 // They are stored by the GDDI tag (second record).
76 int gap1;
77 int gap2;
78 int gap3;
79 int sync;
80 int headerlen;
81 int ecctype; // -1 is CRC
82
sane_rec()83 bool sane_rec() const
84 {
85 return ((interleave > 0 && interleave < 32) && (cylskew >= 0 && cylskew < 32) && (headskew >= 0 && headskew < 32)
86 && (write_precomp_cylinder >= -1 && write_precomp_cylinder < 100000)
87 && (reduced_wcurr_cylinder >= -1 && reduced_wcurr_cylinder < 100000));
88 }
89
reset_rec()90 void reset_rec()
91 {
92 interleave = cylskew = headskew = 0;
93 write_precomp_cylinder = reduced_wcurr_cylinder = -1;
94 }
95
sane_gap()96 bool sane_gap() const
97 {
98 return ((gap1 >= 1 && gap1 < 1000) && (gap2 >= 1 && gap2 < 20) && (gap3 >= 1 && gap3 < 1000)
99 && (sync >= 10 && sync < 20)
100 && (headerlen >= 4 && headerlen<=5) && (ecctype>=-1 && ecctype < 10));
101 }
102
reset_gap()103 void reset_gap()
104 {
105 gap1 = gap2 = gap3 = sync = headerlen = ecctype = 0;
106 }
107
equals_rec(mfmhd_layout_params * other)108 bool equals_rec(mfmhd_layout_params* other) const
109 {
110 return ((interleave == other->interleave) &&
111 (cylskew == other->cylskew) &&
112 (headskew == other->headskew) &&
113 (write_precomp_cylinder == other->write_precomp_cylinder) &&
114 (reduced_wcurr_cylinder == other->reduced_wcurr_cylinder));
115 }
116
equals_gap(mfmhd_layout_params * other)117 bool equals_gap(mfmhd_layout_params* other) const
118 {
119 return ((gap1 == other->gap1) &&
120 (gap2 == other->gap2) &&
121 (gap3 == other->gap3) &&
122 (sync == other->sync) &&
123 (headerlen == other->headerlen) &&
124 (ecctype == other->ecctype));
125 }
126 };
127
128 enum mfmhd_param_t
129 {
130 MFMHD_IL,
131 MFMHD_HSKEW,
132 MFMHD_CSKEW,
133 MFMHD_WPCOM,
134 MFMHD_RWC,
135 MFMHD_GAP1,
136 MFMHD_GAP2,
137 MFMHD_GAP3,
138 MFMHD_SYNC,
139 MFMHD_HLEN,
140 MFMHD_ECC
141 };
142
143 /*
144 Hard disk format
145 */
146 class mfmhd_image_format_t
147 {
148 public:
mfmhd_image_format_t()149 mfmhd_image_format_t(): m_lastbit(false), m_current_crc(0)
150 { m_devtag = std::string("mfmhd_image_format_t"); };
~mfmhd_image_format_t()151 virtual ~mfmhd_image_format_t() {};
152
153 // Load the image.
154 virtual chd_error load(chd_file* chdfile, uint16_t* trackimage, int tracksize, int cylinder, int head) = 0;
155
156 // Save the image.
157 virtual chd_error save(chd_file* chdfile, uint16_t* trackimage, int tracksize, int cylinder, int head) = 0;
158
159 // Return the original parameters of the image
get_initial_params()160 mfmhd_layout_params* get_initial_params() { return &m_param_old; }
161
162 // Return the recent parameters of the image
get_current_params()163 mfmhd_layout_params* get_current_params() { return &m_param; }
164
165 // Set the track layout parameters (and reset the skew detection values)
166 void set_layout_params(mfmhd_layout_params param);
167
168 // Concrete format shall decide whether we want to save the retrieved parameters or not.
169 virtual bool save_param(mfmhd_param_t type) =0;
170
171 // Accept a tag for log output, since this is not a device instance
set_tag(std::string tag)172 void set_tag(std::string tag) { m_devtag = tag; }
173
174 protected:
175 bool m_lastbit;
176 int m_current_crc;
177 int m_secnumber[4]; // used to determine the skew values
178 std::string m_devtag;
179
180 mfmhd_layout_params m_param, m_param_old;
181
182 void mfm_encode(uint16_t* trackimage, int& position, uint8_t byte, int count=1);
183 void mfm_encode_a1(uint16_t* trackimage, int& position);
184 void mfm_encode_mask(uint16_t* trackimage, int& position, uint8_t byte, int count, int mask);
185 uint8_t mfm_decode(uint16_t raw);
186
187 // Deliver defaults.
188 virtual int get_default(mfmhd_param_t type) =0;
189
190 // Debugging
191 void showtrack(uint16_t* enctrack, int length);
tag()192 virtual const char* tag() { return m_devtag.c_str(); }
193 };
194
195 class mfmhd_generic_format : public mfmhd_image_format_t
196 {
197 public:
mfmhd_generic_format()198 mfmhd_generic_format() { m_devtag = std::string("mfmhd_generic_format"); };
199 chd_error load(chd_file* chdfile, uint16_t* trackimage, int tracksize, int cylinder, int head) override;
200 chd_error save(chd_file* chdfile, uint16_t* trackimage, int tracksize, int cylinder, int head) override;
201
202 // Yes, we want to save all parameters
save_param(mfmhd_param_t type)203 virtual bool save_param(mfmhd_param_t type) override { return true; }
204 virtual int get_default(mfmhd_param_t type) override;
205
206 protected:
207 virtual uint8_t cylinder_to_ident(int cylinder);
208 virtual int chs_to_lba(int cylinder, int head, int sector);
209 };
210
211 extern const mfmhd_format_type MFMHD_GEN_FORMAT;
212
213 #endif // MAME_FORMATS_MFM_HD_H
214