src/libfdc/emu_fdc.h

   1 /*
   2  * WD1793/uPD765 emulator
   3  * Copyright (c) 2009-..., SAM style
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a copy
   6  * of this software and associated documentation files (the "Software"), to deal
   7  * in the Software without restriction, including without limitation the rights
   8  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9  * copies of the Software, and to permit persons to whom the Software is furnished
  10  * to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be included in all
  13  * copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  16  * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
  17  * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  18  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  19  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH
  20  * THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * changes by Ketmar // Invisible Vector
  23  *
  24  * Understanding is not required. Only obedience.
  25  */
  26 // FDC emulators, and high-level disk interface API
  27 #ifndef LIBFDC_FDC_H
  28 #define LIBFDC_FDC_H
  29
  30 #include "bdicommon.h"
  31 #include "floppy.h"
  32
  33 #ifdef __cplusplus
  34 extern "C" {
  35 #endif
  36
  37
  38 #define FDC_FAST  (0x01u)
  39
  40 enum {
  41   DIF_NONE = 0,
  42   DIF_BDI,
  43   DIF_P3DOS,
  44   DIF_END = -1
  45 };
  46
  47 #define BDI_SYS   (0xff)
  48 #define FDC_COM   (0x1f)
  49 #define FDC_TRK   (0x3f)
  50 #define FDC_SEC   (0x5f)
  51 #define FDC_DATA  (0x7f)
  52
  53 typedef struct FDC FDC;
  54 typedef void (*fdcCall) (FDC *);
  55
  56 struct FDC {
  57   const int id;
  58   unsigned irq:1;   // VG93:irq; uPD765:exec
  59   unsigned drq:1;   // 0:data request
  60   unsigned dir:1;   // drq dir: 0 - from CPU; 1 - to CPU
  61   unsigned mr:1;    // master reset
  62   unsigned block:1;
  63   unsigned side:1;
  64   unsigned step:1; // step dir
  65   unsigned mfm:1;
  66   unsigned idle:1;
  67   unsigned crchi:1;
  68   // options
  69   unsigned optionTurbo:1;
  70   // other things
  71   uint8_t trk; // registers
  72   uint8_t sec;
  73   uint8_t data;
  74   uint8_t com;
  75   uint8_t state; // vp1-128 : mode (seek/rd/wr)
  76   uint8_t tmp;
  77   uint16_t wdata;
  78   uint16_t tdata;
  79   Floppy *flop[4]; // four floppy drives, always inited by `difCreate()`
  80   Floppy *flp; // current floppy ptr
  81   uint16_t crc; // calculated crc
  82   uint16_t fcrc; // crc get from floppy
  83   uint8_t buf[6];
  84   int fmode;
  85   int cnt;
  86   int wait; // pause (ns)
  87   int tns;
  88   const fdcCall *plan; // current task
  89   unsigned pos; // pos in plan
  90
  91   unsigned dma:1; // not implemented yet
  92   unsigned intr:1; // uPD765 interrupt pending. reset @ com08
  93   int hlt; // head load time (all ns)
  94   int hut; // head unload time
  95   int srt; // step rate time
  96   uint8_t comBuf[8]; // uPD765 command args
  97   int comCnt; // arg count for command
  98   int comPos; // pos in comBuf
  99   uint8_t resBuf[8]; // uPD765 response
 100   int resCnt;
 101   int resPos;
 102   uint8_t sr0, sr1, sr2, sr3; // status registers
 103
 104   /* BDI: last out to sysreg */
 105   uint8_t sysreg;
 106
 107   /* used only in uPD765 emulator */
 108   FDCSector slst[64];
 109   int scnt;
 110 };
 111
 112 typedef struct DiskHW_t DiskHW;
 113 typedef struct DiskIF_t DiskIF;
 114
 115
 116 // create disk interface with the given type
 117 //   DIF_NONE
 118 //   DIF_BDI
 119 //   DIF_P3DOS
 120 // it alwasy creates four floppy drives
 121 // invalid types will become "none"
 122 // default active drive is 0
 123 // default mode is non-turbo
 124 DiskIF *difCreate (int type);
 125
 126 // destroy disk interface
 127 void difDestroy (DiskIF *dif);
 128
 129 // set (force) hardware type for the given interface
 130 //   DIF_NONE
 131 //   DIF_BDI
 132 //   DIF_P3DOS
 133 // invalid types will become "none"
 134 void difSetHW (DiskIF *dif, int type);
 135
 136 // returns hardware type
 137 //   DIF_NONE
 138 //   DIF_BDI
 139 //   DIF_P3DOS
 140 int difGetHW (const DiskIF *dif);
 141
 142 // returns pointer to FDC struct (or NULL)
 143 FDC *difGetFDC (DiskIF *dif);
 144
 145 // returns pointer to Floppy struct (or NULL)
 146 // `driveidx` is [0..3]
 147 Floppy *difGetFloppy (DiskIF *dif, int driveidx);
 148
 149 // returns pointer to Floppy struct (or NULL)
 150 Floppy *difGetCurrentFloppy (DiskIF *dif);
 151
 152 // set "turbo mode"
 153 void difSetTurbo (DiskIF *dif, int v);
 154
 155 // get "turbo mode"
 156 int difGetTurbo (const DiskIF *dif);
 157
 158 // reset disk interface (call on machine reset)
 159 void difReset (DiskIF *dif);
 160
 161 // tstates: tstates passed
 162 // cpufreq: 3500000 for ZX Spectrum
 163 int difCalcNSFromTStates (int tstates, int cpufreq);
 164
 165 // update disk interface (up to the given `ns`)
 166 // call this in emulation loop
 167 // `ns` is time passed from the last call (in nanoseconds)
 168 // it can be calculated with `difCalcNSFromTStates()`
 169 // sync disk interface before in/out, and on each frame
 170 void difSync (DiskIF *dif, int ns);
 171
 172 // write value into FDC port
 173 // WARNING: call only when FDC ports are active!
 174 // returns `-1` if not an FDC port
 175 // note that `0` means success!
 176 int difOut (DiskIF *dif, int port, int val);
 177
 178 // write value into FDC port
 179 // WARNING: call only when FDC ports are active!
 180 // returns `-1` if not an FDC port
 181 int difIn (DiskIF *dif, int port);
 182
 183 // utility function used by both FDCs
 184 //void fdcUpdateCRC16 (FDC *fdc, uint8_t val);
 185
 186 #ifdef __cplusplus
 187 }
 188 #endif
 189 #endif