AltairZ80/s100_fif.c - emulators/simh - Rivoreo Source Code Repositories

 /*  $Id: s100_fif.c 1995 2008-07-15 03:59:13Z hharte $

     IMSAI FIF Disk Controller by Ernie Price

     Based on altairz80_dsk.c, Copyright (c) 2002-2011, Peter Schorn

     Plug-n-Play added by Howard M. Harte

     Permission is hereby granted, free of charge, to any person obtaining a
     copy of this software and associated documentation files (the "Software"),
     to deal in the Software without restriction, including without limitation
     the rights to use, copy, modify, merge, publish, distribute, sublicense,
     and/or sell copies of the Software, and to permit persons to whom the
     Software is furnished to do so, subject to the following conditions:

     The above copyright notice and this permission notice shall be included in
     all copies or substantial portions of the Software.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     PETER SCHORN BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
     IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
     CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

     Except as contained in this notice, the name of Peter Schorn shall not
     be used in advertising or otherwise to promote the sale, use or other dealings
     in this Software without prior written authorization from Peter Schorn.

 */

 #include "altairz80_defs.h"

 #define UNIT_V_DSK_WLK      (UNIT_V_UF + 0) /* write locked                             */
 #define UNIT_DSK_WLK        (1 << UNIT_V_DSK_WLK)
 #define UNIT_V_DSK_VERBOSE  (UNIT_V_UF + 1) /* verbose mode, i.e. show error messages   */
 #define UNIT_DSK_VERBOSE    (1 << UNIT_V_DSK_VERBOSE)
 #define DSK_SECTSIZE        137 /* size of sector                                       */
 #define DSK_SECT            32  /* sectors per track                                    */
 #define MAX_TRACKS          254 /* number of tracks, original Altair has 77 tracks only */
 #define DSK_TRACSIZE        (DSK_SECTSIZE * DSK_SECT)
 #define MAX_DSK_SIZE        (DSK_TRACSIZE * MAX_TRACKS)

 static t_stat fif_reset(DEVICE *dptr);
 static t_stat fif_set_verbose(UNIT *uptr, int32 value, char *cptr, void *desc);
 static int32 fif_io(const int32 port, const int32 io, const int32 data);

 extern t_stat set_iobase(UNIT *uptr, int32 val, char *cptr, void *desc);
 extern t_stat show_iobase(FILE *st, UNIT *uptr, int32 val, void *desc);
 extern uint32 sim_map_resource(uint32 baseaddr, uint32 size, uint32 resource_type,
         int32 (*routine)(const int32, const int32, const int32), uint8 unmap);
 extern uint8 GetBYTEWrapper(const uint32 Addr);
 extern void  PutBYTEWrapper(const uint32 Addr, const uint32 Value);

 extern uint32 PCX;

 /* global data on status */

 /* currently selected drive (values are 0 .. NUM_OF_DSK)
    current_disk < NUM_OF_DSK implies that the corresponding disk is attached to a file */
 static int32 current_disk                   = NUM_OF_DSK;
 static int32 warnLevelDSK                   = 3;
 static int32 warnLock       [NUM_OF_DSK]    = {0, 0, 0, 0, 0, 0, 0, 0};
 static int32 warnAttached   [NUM_OF_DSK]    = {0, 0, 0, 0, 0, 0, 0, 0};
 static int32 warnDSK11                      = 0;

 /* 88DSK Standard I/O Data Structures */

 typedef struct {
     PNP_INFO    pnp;    /* Plug and Play */
 } FIF_INFO;

 FIF_INFO fif_info_data = { { 0x0000, 0, 0xFD, 1 } };
 FIF_INFO *fif_info = &fif_info_data;

 static UNIT fif_unit[] = {
     { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
     { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
     { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
     { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
     { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
     { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
     { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
     { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }
 };

 static REG fif_reg[] = {
     { DRDATA (DISK,         current_disk,   4)                                          },
     { DRDATA (DSKWL,        warnLevelDSK, 32)                                           },
     { BRDATA (WARNLOCK,     warnLock,       10, 32, NUM_OF_DSK),    REG_CIRC + REG_RO   },
     { BRDATA (WARNATTACHED, warnAttached,   10, 32, NUM_OF_DSK),    REG_CIRC + REG_RO   },
     { DRDATA (WARNDSK11,    warnDSK11, 4),                          REG_RO              },
     { NULL }
 };

 static MTAB fif_mod[] = {
     { MTAB_XTD|MTAB_VDV, 0,                 "IOBASE",   "IOBASE",   &set_iobase, &show_iobase, NULL },
     { UNIT_DSK_WLK,     0,                  "WRTENB",   "WRTENB",   NULL },
     { UNIT_DSK_WLK,     UNIT_DSK_WLK,       "WRTLCK",   "WRTLCK",   NULL },
     /* quiet, no warning messages       */
     { UNIT_DSK_VERBOSE, 0,                  "QUIET",    "QUIET",    NULL },
     /* verbose, show warning messages   */
     { UNIT_DSK_VERBOSE, UNIT_DSK_VERBOSE,   "VERBOSE",  "VERBOSE",  &fif_set_verbose },
     { 0 }
 };

 DEVICE fif_dev = {
     "FIF", fif_unit, fif_reg, fif_mod,
     8, 10, 31, 1, 8, 8,
     NULL, NULL, &fif_reset,
     NULL, NULL, NULL,
     &fif_info_data, (DEV_DISABLE | DEV_DIS), 0,
     NULL, NULL, "IMSAI FIF"
 };

 static void resetDSKWarningFlags(void) {
     int32 i;
     for (i = 0; i < NUM_OF_DSK; i++) {
         warnLock[i]         = 0;
         warnAttached[i]     = 0;
     }
     warnDSK11 = 0;
 }

 static t_stat fif_set_verbose(UNIT *uptr, int32 value, char *cptr, void *desc) {
     resetDSKWarningFlags();
     return SCPE_OK;
 }

 /* returns TRUE iff there exists a disk with VERBOSE */
 static int32 hasVerbose(void) {
     int32 i;
     for (i = 0; i < NUM_OF_DSK; i++) {
         if (((fif_dev.units + i) -> flags) & UNIT_DSK_VERBOSE) {
             return TRUE;
         }
     }
     return FALSE;
 }

 /* service routines to handle simulator functions */

 /* Reset routine */
 static t_stat fif_reset(DEVICE *dptr)
 {
     PNP_INFO *pnp = (PNP_INFO *)dptr->ctxt;

     resetDSKWarningFlags();
     current_disk = NUM_OF_DSK;

     if(dptr->flags & DEV_DIS) {
         sim_map_resource(pnp->io_base, pnp->io_size, RESOURCE_TYPE_IO, &fif_io, TRUE);
     } else {
         /* Connect HDSK at base address */
         if(sim_map_resource(pnp->io_base, pnp->io_size, RESOURCE_TYPE_IO, &fif_io, FALSE) != 0) {
             printf("%s: error mapping I/O resource at 0x%04x\n", __FUNCTION__, pnp->mem_base);
             dptr->flags |= DEV_DIS;
             return SCPE_ARG;
         }
     }
     return SCPE_OK;
 }

 typedef struct desc_t
 {
     uint8
         cmd_unit,   /* (cmd << 4) | unit : 1 = A: */
         result,     /* result: 0 == busy, 1 = normal completion, */
         nn,         /* number of secs ? */
         track,      /* track */
         sector,     /* sector */
         addr_l,     /* low  (transfer address) */
         addr_h;     /* high (transfer address) */
 } desc_t;

 static desc_t mydesc;

 enum {NONE, WRITE_SEC, READ_SEC, FMT_TRACK};

 #define SEC_SZ      128
 #define SPT         26
 #define UMASK       0xf

 static uint8 blanksec[SEC_SZ];
 /*                      0 1 2 3 4 5 6 7 8 9 a b c d e f */
 static const uint8 utrans[] = {0,1,2,0,3,0,0,0,4,0,0,0,0,0,0,0};

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

     Translate an IMSAI FIF disk request into an access into the harddrive file

 */
 static int DoDiskOperation(desc_t *dsc, uint8 val)
 {
     int32   current_disk_flags;
     int     kt,
             addr;
     FILE    *cpx;
     UNIT    *uptr;
     int32   rtn;

 #if 0
     printf("%02x %02x %02x %02x %02x %02x %02x %02x \n",
         val,
         dsc->cmd_unit,
         dsc->result,
         dsc->nn,
         dsc->track,
         dsc->sector,
         dsc->addr_l,
         dsc->addr_h);
 #endif

     current_disk = (utrans[dsc->cmd_unit & UMASK]) - 1; /* 0 <= current_disk < NUM_OF_DSK */
     if (current_disk >= NUM_OF_DSK) {
         if (hasVerbose() && (warnDSK11 < warnLevelDSK)) {
             warnDSK11++;
 /*03*/      printf("FIF%i: " ADDRESS_FORMAT " Attempt disk io on illegal disk %d - ignored." NLP, current_disk, PCX, current_disk);
         }
         return 0;               /* no drive selected - can do nothing */
     }
     current_disk_flags = (fif_dev.units + current_disk) -> flags;
     if ((current_disk_flags & UNIT_ATT) == 0) { /* nothing attached? */
         if ( (current_disk_flags & UNIT_DSK_VERBOSE) && (warnAttached[current_disk] < warnLevelDSK) ) {
             warnAttached[current_disk]++;
 /*02*/printf("FIF%i: " ADDRESS_FORMAT " Attempt to select unattached FIF%d - ignored." NLP, current_disk, PCX, current_disk);
         }
         current_disk = NUM_OF_DSK;
         return 2;
     }

     uptr = fif_dev.units + current_disk;
     cpx = uptr->fileref;

     /* decode request: */
     switch (dsc->cmd_unit >> 4) {
         case FMT_TRACK:
             /*printf("%c", dsc->track % 10 ? '*' : '0' + + dsc->track / 10); */
             /*Sleep(250); */
             memset(blanksec, 0, SEC_SZ);
             addr = dsc->track * SPT;
             sim_fseek(cpx, addr * SEC_SZ, SEEK_SET);

             /* write a track worth of sectors */
             for (kt=0; kt < SPT; kt++) {
                 sim_fwrite(blanksec, 1, sizeof(blanksec), cpx);
             }
             break;

         case READ_SEC:
             addr = (dsc->track * SPT) + dsc->sector - 1;
             sim_fseek(cpx, addr * SEC_SZ, SEEK_SET);
             rtn = sim_fread(blanksec, 1, SEC_SZ, cpx);
             if ( (rtn != SEC_SZ) && (current_disk_flags & UNIT_DSK_VERBOSE) &&
                 (warnAttached[current_disk] < warnLevelDSK) ) {
                 warnAttached[current_disk]++;
                 printf("FIF%i: " ADDRESS_FORMAT " sim_fread error." NLP, current_disk, PCX);
             }
             addr = dsc->addr_l + (dsc->addr_h << 8); /* no assumption on endianness */
             for (kt = 0; kt < SEC_SZ; kt++) {
                 PutBYTEWrapper(addr++, blanksec[kt]);
             }
             break;

         case WRITE_SEC:
             addr = (dsc->track * SPT) + dsc->sector - 1;
             sim_fseek(cpx, addr * SEC_SZ, SEEK_SET);
             addr = dsc->addr_l + (dsc->addr_h << 8); /* no assumption on endianness */
             for (kt = 0; kt < SEC_SZ; kt++) {
                 blanksec[kt] = GetBYTEWrapper(addr++);
             }
             sim_fwrite(blanksec, 1, SEC_SZ, cpx);
             break;

         default:
             ;
     }
     return 1;
 }

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

     Copy the disk descriptor from target RAM

 */
 static void getdesc(uint16 addr) {
     uint32 x;
     uint8 *p1 = (uint8*)&mydesc;

     for (x = 0; x < sizeof(mydesc); x++) {
         *p1++ = GetBYTEWrapper(addr++);
     }
 }

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

     handle the IMSAI FIF floppy controller

 */
 static int32 fif_io(const int32 port, const int32 io, const int32 data) {

     static int32    fdstate = 0;    /* chan 0xfd state */
     static int32    desc;
     static uint16   fdAdr[16];      /* disk descriptor address in 8080/z80 RAM */

     /* cmd | desc# */
     /*    cmd == 0x00 do operation */
     /*    cmd == 0x10 next 2 transfers are desc address */
     /* desc# is one of 16 0x0 - 0xf */

     if (!io) {
         return 0;
     }

     switch (fdstate) {
         case 0:
             desc = data & 0xf;
             if ((data & 0x10) != 0) { /* prefix 0x10 */
                 fdstate++;          /* means desc address is next 2 out (fd),a */
             }
             else { /* do what descriptor says */
                 getdesc(fdAdr[desc]);
                 PutBYTEWrapper(fdAdr[desc] + 1,
                     (uint8)DoDiskOperation(&mydesc, (uint8)data));
             }
             break;

         case 1:
             /*printf("D1 %02x %02x\n", desc, data); */
             fdAdr[desc] = data;        /* LSB of descriptor address */
             fdstate++;
             break;

         case 2:
             /*printf("D2 %02x %02x\n", desc, data); */
             fdAdr[desc] |= data << 8;  /* MSB of descriptor address */
             fdstate = 0;
             break;
     }
     return 0;
 }

 #define ERNIES_FTP 0
 #if ERNIES_FTP

 #define WRK_BUF_SZ  150
 #define FCB_SIZE    32
 #define NAME_LTH    8
 #define EXT_LTH     3


 /**************************************************
 */
 static void xfero(int32 addr, char *src, int32 lth)
 {
     while (lth--) {
         PutBYTEWrapper(addr++, *src++);
     }
 }

 /**************************************************
 */
 static void xferi(int32 addr, char *dst, int32 lth)
 {
     while (lth--) {
         *dst++ = GetBYTEWrapper(addr++);
     }
 }

 #if !defined (_WIN32)
 static void strupr(char *fn) {
     while (*fn) {
         if (('a' <= *fn) && (*fn <= 'z'))
             *fn -= 'a' - 'A';
         fn++;
     }
 }
 #endif

 /**************************************************
 */
 static void initfcb(char *fcb, char *fn, int32 flg)
 {
     char *p1 = fcb;

     if (flg)
     {
         strupr(fn);
     }
     memset (fcb, 0 , FCB_SIZE);
     memset (fcb + 1, ' ', NAME_LTH + EXT_LTH);
     p1++;
     while (*fn && (*fn != '.'))
     {
         *p1++ = *fn++;
     }
     if (*fn == '.')
     {
         fn++;
     }
     p1 = fcb + NAME_LTH + 1;
     while (*fn && (*fn != '.'))
     {
         *p1++ = *fn++;
     }
 }

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

     FTP interface - most of the work is done here
     The IMDOS/CPM application only does minimal work

 */

 char message[WRK_BUF_SZ];
 char temp   [WRK_BUF_SZ];
 FILE * myfile;

 uint8 FTP(int32 BC, int32 DE)
 {
     char   *p1, *p2;
     int32   retval;

     xferi(DE, temp, SEC_SZ);
     p1 = temp;
     switch (BC & 0x7f)
     {
         case 0:
             memcpy(message, p1 + 2, *(p1 + 1));
             *(message + *(p1 + 1)) = 0;
             p2 = strtok(message, " \t");
             if (!strcmp(p2, "get"))
             {
                 p2 = strtok(NULL, " \t");
                 if (myfile = fopen(p2, "rb"))
                 {
                     initfcb(temp, p2, 1);
                     xfero(DE + 2, temp, 32);
                     retval = 0;
                     break;
                 }
             }
             if (!strcmp(p2, "era"))
             {
                 p2 = strtok(NULL, " \t");
                 initfcb(temp, p2, 0);
                 xfero(DE + 2, temp, 32);
                 retval = 1;
                 break;
             }
             retval = 0xff;
             break;

         case 20:
             memset(temp, 0x1a, SEC_SZ);
             retval = sim_fread(temp, 1, SEC_SZ, myfile) ? 0 : 1;
             xfero( DE, temp, SEC_SZ);
             if (retval)
             {
                 fclose(myfile);
             }
             break;
     }
     return retval;
 }

 #endif /* ERNIES_FTP */

 /* end of the source */
	/* $Id: s100_fif.c 1995 2008-07-15 03:59:13Z hharte $

	IMSAI FIF Disk Controller by Ernie Price

	Based on altairz80_dsk.c, Copyright (c) 2002-2011, Peter Schorn

	Plug-n-Play added by Howard M. Harte

	Permission is hereby granted, free of charge, to any person obtaining a
	copy of this software and associated documentation files (the "Software"),
	to deal in the Software without restriction, including without limitation
	the rights to use, copy, modify, merge, publish, distribute, sublicense,
	and/or sell copies of the Software, and to permit persons to whom the
	Software is furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in
	all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	PETER SCHORN BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
	IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

	Except as contained in this notice, the name of Peter Schorn shall not
	be used in advertising or otherwise to promote the sale, use or other dealings
	in this Software without prior written authorization from Peter Schorn.

	*/

	#include "altairz80_defs.h"

	#define UNIT_V_DSK_WLK (UNIT_V_UF + 0) /* write locked */
	#define UNIT_DSK_WLK (1 << UNIT_V_DSK_WLK)
	#define UNIT_V_DSK_VERBOSE (UNIT_V_UF + 1) /* verbose mode, i.e. show error messages */
	#define UNIT_DSK_VERBOSE (1 << UNIT_V_DSK_VERBOSE)
	#define DSK_SECTSIZE 137 /* size of sector */
	#define DSK_SECT 32 /* sectors per track */
	#define MAX_TRACKS 254 /* number of tracks, original Altair has 77 tracks only */
	#define DSK_TRACSIZE (DSK_SECTSIZE * DSK_SECT)
	#define MAX_DSK_SIZE (DSK_TRACSIZE * MAX_TRACKS)

	static t_stat fif_reset(DEVICE *dptr);
	static t_stat fif_set_verbose(UNIT uptr, int32 value, char cptr, void *desc);
	static int32 fif_io(const int32 port, const int32 io, const int32 data);

	extern t_stat set_iobase(UNIT uptr, int32 val, char cptr, void *desc);
	extern t_stat show_iobase(FILE st, UNIT uptr, int32 val, void *desc);
	extern uint32 sim_map_resource(uint32 baseaddr, uint32 size, uint32 resource_type,
	int32 (*routine)(const int32, const int32, const int32), uint8 unmap);
	extern uint8 GetBYTEWrapper(const uint32 Addr);
	extern void PutBYTEWrapper(const uint32 Addr, const uint32 Value);

	extern uint32 PCX;

	/* global data on status */

	/* currently selected drive (values are 0 .. NUM_OF_DSK)
	current_disk < NUM_OF_DSK implies that the corresponding disk is attached to a file */
	static int32 current_disk = NUM_OF_DSK;
	static int32 warnLevelDSK = 3;
	static int32 warnLock [NUM_OF_DSK] = {0, 0, 0, 0, 0, 0, 0, 0};
	static int32 warnAttached [NUM_OF_DSK] = {0, 0, 0, 0, 0, 0, 0, 0};
	static int32 warnDSK11 = 0;

	/* 88DSK Standard I/O Data Structures */

	typedef struct {
	PNP_INFO pnp; /* Plug and Play */
	} FIF_INFO;

	FIF_INFO fif_info_data = { { 0x0000, 0, 0xFD, 1 } };
	FIF_INFO *fif_info = &fif_info_data;

	static UNIT fif_unit[] = {
	{ UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
	{ UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
	{ UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
	{ UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
	{ UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
	{ UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
	{ UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) },
	{ UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }
	};

	static REG fif_reg[] = {
	{ DRDATA (DISK, current_disk, 4) },
	{ DRDATA (DSKWL, warnLevelDSK, 32) },
	{ BRDATA (WARNLOCK, warnLock, 10, 32, NUM_OF_DSK), REG_CIRC + REG_RO },
	{ BRDATA (WARNATTACHED, warnAttached, 10, 32, NUM_OF_DSK), REG_CIRC + REG_RO },
	{ DRDATA (WARNDSK11, warnDSK11, 4), REG_RO },
	{ NULL }
	};

	static MTAB fif_mod[] = {
	{ MTAB_XTD\|MTAB_VDV, 0, "IOBASE", "IOBASE", &set_iobase, &show_iobase, NULL },
	{ UNIT_DSK_WLK, 0, "WRTENB", "WRTENB", NULL },
	{ UNIT_DSK_WLK, UNIT_DSK_WLK, "WRTLCK", "WRTLCK", NULL },
	/* quiet, no warning messages */
	{ UNIT_DSK_VERBOSE, 0, "QUIET", "QUIET", NULL },
	/* verbose, show warning messages */
	{ UNIT_DSK_VERBOSE, UNIT_DSK_VERBOSE, "VERBOSE", "VERBOSE", &fif_set_verbose },
	{ 0 }
	};

	DEVICE fif_dev = {
	"FIF", fif_unit, fif_reg, fif_mod,
	8, 10, 31, 1, 8, 8,
	NULL, NULL, &fif_reset,
	NULL, NULL, NULL,
	&fif_info_data, (DEV_DISABLE \| DEV_DIS), 0,
	NULL, NULL, "IMSAI FIF"
	};

	static void resetDSKWarningFlags(void) {
	int32 i;
	for (i = 0; i < NUM_OF_DSK; i++) {
	warnLock[i] = 0;
	warnAttached[i] = 0;
	}
	warnDSK11 = 0;
	}

	static t_stat fif_set_verbose(UNIT uptr, int32 value, char cptr, void *desc) {
	resetDSKWarningFlags();
	return SCPE_OK;
	}

	/* returns TRUE iff there exists a disk with VERBOSE */
	static int32 hasVerbose(void) {
	int32 i;
	for (i = 0; i < NUM_OF_DSK; i++) {
	if (((fif_dev.units + i) -> flags) & UNIT_DSK_VERBOSE) {
	return TRUE;
	}
	}
	return FALSE;
	}

	/* service routines to handle simulator functions */

	/* Reset routine */
	static t_stat fif_reset(DEVICE *dptr)
	{
	PNP_INFO pnp = (PNP_INFO )dptr->ctxt;

	resetDSKWarningFlags();
	current_disk = NUM_OF_DSK;

	if(dptr->flags & DEV_DIS) {
	sim_map_resource(pnp->io_base, pnp->io_size, RESOURCE_TYPE_IO, &fif_io, TRUE);
	} else {
	/* Connect HDSK at base address */
	if(sim_map_resource(pnp->io_base, pnp->io_size, RESOURCE_TYPE_IO, &fif_io, FALSE) != 0) {
	printf("%s: error mapping I/O resource at 0x%04x\n", __FUNCTION__, pnp->mem_base);
	dptr->flags \|= DEV_DIS;
	return SCPE_ARG;
	}
	}
	return SCPE_OK;
	}

	typedef struct desc_t
	{
	uint8
	cmd_unit, /* (cmd << 4) \| unit : 1 = A: */
	result, /* result: 0 == busy, 1 = normal completion, */
	nn, /* number of secs ? */
	track, /* track */
	sector, /* sector */
	addr_l, /* low (transfer address) */
	addr_h; /* high (transfer address) */
	} desc_t;

	static desc_t mydesc;

	enum {NONE, WRITE_SEC, READ_SEC, FMT_TRACK};

	#define SEC_SZ 128
	#define SPT 26
	#define UMASK 0xf

	static uint8 blanksec[SEC_SZ];
	/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
	static const uint8 utrans[] = {0,1,2,0,3,0,0,0,4,0,0,0,0,0,0,0};

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

	Translate an IMSAI FIF disk request into an access into the harddrive file

	*/
	static int DoDiskOperation(desc_t *dsc, uint8 val)
	{
	int32 current_disk_flags;
	int kt,
	addr;
	FILE *cpx;
	UNIT *uptr;
	int32 rtn;

	#if 0
	printf("%02x %02x %02x %02x %02x %02x %02x %02x \n",
	val,
	dsc->cmd_unit,
	dsc->result,
	dsc->nn,
	dsc->track,
	dsc->sector,
	dsc->addr_l,
	dsc->addr_h);
	#endif

	current_disk = (utrans[dsc->cmd_unit & UMASK]) - 1; /* 0 <= current_disk < NUM_OF_DSK */
	if (current_disk >= NUM_OF_DSK) {
	if (hasVerbose() && (warnDSK11 < warnLevelDSK)) {
	warnDSK11++;
	/03/ printf("FIF%i: " ADDRESS_FORMAT " Attempt disk io on illegal disk %d - ignored." NLP, current_disk, PCX, current_disk);
	}
	return 0; /* no drive selected - can do nothing */
	}
	current_disk_flags = (fif_dev.units + current_disk) -> flags;
	if ((current_disk_flags & UNIT_ATT) == 0) { /* nothing attached? */
	if ( (current_disk_flags & UNIT_DSK_VERBOSE) && (warnAttached[current_disk] < warnLevelDSK) ) {
	warnAttached[current_disk]++;
	/02/printf("FIF%i: " ADDRESS_FORMAT " Attempt to select unattached FIF%d - ignored." NLP, current_disk, PCX, current_disk);
	}
	current_disk = NUM_OF_DSK;
	return 2;
	}

	uptr = fif_dev.units + current_disk;
	cpx = uptr->fileref;

	/* decode request: */
	switch (dsc->cmd_unit >> 4) {
	case FMT_TRACK:
	/printf("%c", dsc->track % 10 ? '' : '0' + + dsc->track / 10); */
	/Sleep(250); /
	memset(blanksec, 0, SEC_SZ);
	addr = dsc->track * SPT;
	sim_fseek(cpx, addr * SEC_SZ, SEEK_SET);

	/* write a track worth of sectors */
	for (kt=0; kt < SPT; kt++) {
	sim_fwrite(blanksec, 1, sizeof(blanksec), cpx);
	}
	break;

	case READ_SEC:
	addr = (dsc->track * SPT) + dsc->sector - 1;
	sim_fseek(cpx, addr * SEC_SZ, SEEK_SET);
	rtn = sim_fread(blanksec, 1, SEC_SZ, cpx);
	if ( (rtn != SEC_SZ) && (current_disk_flags & UNIT_DSK_VERBOSE) &&
	(warnAttached[current_disk] < warnLevelDSK) ) {
	warnAttached[current_disk]++;
	printf("FIF%i: " ADDRESS_FORMAT " sim_fread error." NLP, current_disk, PCX);
	}
	addr = dsc->addr_l + (dsc->addr_h << 8); /* no assumption on endianness */
	for (kt = 0; kt < SEC_SZ; kt++) {
	PutBYTEWrapper(addr++, blanksec[kt]);
	}
	break;

	case WRITE_SEC:
	addr = (dsc->track * SPT) + dsc->sector - 1;
	sim_fseek(cpx, addr * SEC_SZ, SEEK_SET);
	addr = dsc->addr_l + (dsc->addr_h << 8); /* no assumption on endianness */
	for (kt = 0; kt < SEC_SZ; kt++) {
	blanksec[kt] = GetBYTEWrapper(addr++);
	}
	sim_fwrite(blanksec, 1, SEC_SZ, cpx);
	break;

	default:
	;
	}
	return 1;
	}

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

	Copy the disk descriptor from target RAM

	*/
	static void getdesc(uint16 addr) {
	uint32 x;
	uint8 p1 = (uint8)&mydesc;

	for (x = 0; x < sizeof(mydesc); x++) {
	*p1++ = GetBYTEWrapper(addr++);
	}
	}

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

	handle the IMSAI FIF floppy controller

	*/
	static int32 fif_io(const int32 port, const int32 io, const int32 data) {

	static int32 fdstate = 0; /* chan 0xfd state */
	static int32 desc;
	static uint16 fdAdr[16]; /* disk descriptor address in 8080/z80 RAM */

	/* cmd \| desc# */
	/* cmd == 0x00 do operation */
	/* cmd == 0x10 next 2 transfers are desc address */
	/* desc# is one of 16 0x0 - 0xf */

	if (!io) {
	return 0;
	}

	switch (fdstate) {
	case 0:
	desc = data & 0xf;
	if ((data & 0x10) != 0) { /* prefix 0x10 */
	fdstate++; /* means desc address is next 2 out (fd),a */
	}
	else { /* do what descriptor says */
	getdesc(fdAdr[desc]);
	PutBYTEWrapper(fdAdr[desc] + 1,
	(uint8)DoDiskOperation(&mydesc, (uint8)data));
	}
	break;

	case 1:
	/printf("D1 %02x %02x\n", desc, data); /
	fdAdr[desc] = data; /* LSB of descriptor address */
	fdstate++;
	break;

	case 2:
	/printf("D2 %02x %02x\n", desc, data); /
	fdAdr[desc] \|= data << 8; /* MSB of descriptor address */
	fdstate = 0;
	break;
	}
	return 0;
	}

	#define ERNIES_FTP 0
	#if ERNIES_FTP

	#define WRK_BUF_SZ 150
	#define FCB_SIZE 32
	#define NAME_LTH 8
	#define EXT_LTH 3


	/**************************************************
	*/
	static void xfero(int32 addr, char *src, int32 lth)
	{
	while (lth--) {
	PutBYTEWrapper(addr++, *src++);
	}
	}

	/**************************************************
	*/
	static void xferi(int32 addr, char *dst, int32 lth)
	{
	while (lth--) {
	*dst++ = GetBYTEWrapper(addr++);
	}
	}

	#if !defined (_WIN32)
	static void strupr(char *fn) {
	while (*fn) {
	if (('a' <= fn) && (fn <= 'z'))
	*fn -= 'a' - 'A';
	fn++;
	}
	}
	#endif

	/**************************************************
	*/
	static void initfcb(char fcb, char fn, int32 flg)
	{
	char *p1 = fcb;

	if (flg)
	{
	strupr(fn);
	}
	memset (fcb, 0 , FCB_SIZE);
	memset (fcb + 1, ' ', NAME_LTH + EXT_LTH);
	p1++;
	while (fn && (fn != '.'))
	{
	p1++ = fn++;
	}
	if (*fn == '.')
	{
	fn++;
	}
	p1 = fcb + NAME_LTH + 1;
	while (fn && (fn != '.'))
	{
	p1++ = fn++;
	}
	}

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

	FTP interface - most of the work is done here
	The IMDOS/CPM application only does minimal work

	*/

	char message[WRK_BUF_SZ];
	char temp [WRK_BUF_SZ];
	FILE * myfile;

	uint8 FTP(int32 BC, int32 DE)
	{
	char p1, p2;
	int32 retval;

	xferi(DE, temp, SEC_SZ);
	p1 = temp;
	switch (BC & 0x7f)
	{
	case 0:
	memcpy(message, p1 + 2, *(p1 + 1));
	(message + (p1 + 1)) = 0;
	p2 = strtok(message, " \t");
	if (!strcmp(p2, "get"))
	{
	p2 = strtok(NULL, " \t");
	if (myfile = fopen(p2, "rb"))
	{
	initfcb(temp, p2, 1);
	xfero(DE + 2, temp, 32);
	retval = 0;
	break;
	}
	}
	if (!strcmp(p2, "era"))
	{
	p2 = strtok(NULL, " \t");
	initfcb(temp, p2, 0);
	xfero(DE + 2, temp, 32);
	retval = 1;
	break;
	}
	retval = 0xff;
	break;

	case 20:
	memset(temp, 0x1a, SEC_SZ);
	retval = sim_fread(temp, 1, SEC_SZ, myfile) ? 0 : 1;
	xfero( DE, temp, SEC_SZ);
	if (retval)
	{
	fclose(myfile);
	}
	break;
	}
	return retval;
	}

	#endif /* ERNIES_FTP */

	/* end of the source */