| /* altairz80_dsk.c: MITS Altair 88-DISK Simulator | |
| Copyright (c) 2002-2005, Peter Schorn | |
| 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. | |
| Based on work by Charles E Owen (c) 1997 | |
| The 88_DISK is a 8-inch floppy controller which can control up | |
| to 16 daisy-chained Pertec FD-400 hard-sectored floppy drives. | |
| Each diskette has physically 77 tracks of 32 137-byte sectors | |
| each. | |
| The controller is interfaced to the CPU by use of 3 I/O addresses, | |
| standardly, these are device numbers 10, 11, and 12 (octal). | |
| Address Mode Function | |
| ------- ---- -------- | |
| 10 Out Selects and enables Controller and Drive | |
| 10 In Indicates status of Drive and Controller | |
| 11 Out Controls Disk Function | |
| 11 In Indicates current sector position of disk | |
| 12 Out Write data | |
| 12 In Read data | |
| Drive Select Out (Device 10 OUT): | |
| +---+---+---+---+---+---+---+---+ | |
| | C | X | X | X | Device | | |
| +---+---+---+---+---+---+---+---+ | |
| C = If this bit is 1, the disk controller selected by 'device' is | |
| cleared. If the bit is zero, 'device' is selected as the | |
| device being controlled by subsequent I/O operations. | |
| X = not used | |
| Device = value zero thru 15, selects drive to be controlled. | |
| Drive Status In (Device 10 IN): | |
| +---+---+---+---+---+---+---+---+ | |
| | R | Z | I | X | X | H | M | W | | |
| +---+---+---+---+---+---+---+---+ | |
| W - When 0, write circuit ready to write another byte. | |
| M - When 0, head movement is allowed | |
| H - When 0, indicates head is loaded for read/write | |
| X - not used (will be 0) | |
| I - When 0, indicates interrupts enabled (not used by this simulator) | |
| Z - When 0, indicates head is on track 0 | |
| R - When 0, indicates that read circuit has new byte to read | |
| Drive Control (Device 11 OUT): | |
| +---+---+---+---+---+---+---+---+ | |
| | W | C | D | E | U | H | O | I | | |
| +---+---+---+---+---+---+---+---+ | |
| I - When 1, steps head IN one track | |
| O - When 1, steps head OUT one track | |
| H - When 1, loads head to drive surface | |
| U - When 1, unloads head | |
| E - Enables interrupts (ignored by this simulator) | |
| D - Disables interrupts (ignored by this simulator) | |
| C - When 1 lowers head current (ignored by this simulator) | |
| W - When 1, starts Write Enable sequence: W bit on device 10 | |
| (see above) will go 1 and data will be read from port 12 | |
| until 137 bytes have been read by the controller from | |
| that port. The W bit will go off then, and the sector data | |
| will be written to disk. Before you do this, you must have | |
| stepped the track to the desired number, and waited until | |
| the right sector number is presented on device 11 IN, then | |
| set this bit. | |
| Sector Position (Device 11 IN): | |
| As the sectors pass by the read head, they are counted and the | |
| number of the current one is available in this register. | |
| +---+---+---+---+---+---+---+---+ | |
| | X | X | Sector Number | T | | |
| +---+---+---+---+---+---+---+---+ | |
| X = Not used | |
| Sector number = binary of the sector number currently under the | |
| head, 0-31. | |
| T = Sector True, is a 1 when the sector is positioned to read or | |
| write. | |
| */ | |
| #include "altairz80_defs.h" | |
| #define UNIT_V_DSKWLK (UNIT_V_UF + 0) /* write locked */ | |
| #define UNIT_DSKWLK (1 << UNIT_V_DSKWLK) | |
| #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) | |
| #define TRACE_IN_OUT 1 | |
| #define TRACE_READ_WRITE 2 | |
| #define TRACE_SECTOR_STUCK 4 | |
| #define TRACE_TRACK_STUCK 8 | |
| #define NUM_OF_DSK_MASK (NUM_OF_DSK - 1) | |
| int32 dsk10(const int32 port, const int32 io, const int32 data); | |
| int32 dsk11(const int32 port, const int32 io, const int32 data); | |
| int32 dsk12(const int32 port, const int32 io, const int32 data); | |
| static int32 dskseek(const UNIT *xptr); | |
| static t_stat dsk_boot(int32 unitno, DEVICE *dptr); | |
| static t_stat dsk_reset(DEVICE *dptr); | |
| static t_stat dsk_svc(UNIT *uptr); | |
| static void writebuf(void); | |
| static t_stat dsk_set_verbose(UNIT *uptr, int32 value, char *cptr, void *desc); | |
| static void resetDSKWarningFlags(void); | |
| static int32 hasVerbose(void); | |
| static char* selectInOut(const int32 io); | |
| extern int32 PCX; | |
| extern int32 saved_PC; | |
| extern FILE *sim_log; | |
| extern void printMessage(void); | |
| extern char messageBuffer[]; | |
| extern int32 install_bootrom(void); | |
| extern UNIT cpu_unit; | |
| /* global data on status */ | |
| static int32 current_disk = NUM_OF_DSK; /* 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_track [NUM_OF_DSK] = {0, 0, 0, 0, 0, 0, 0, 0}; | |
| static int32 current_sector [NUM_OF_DSK] = {0, 0, 0, 0, 0, 0, 0, 0}; | |
| static int32 current_byte [NUM_OF_DSK] = {0, 0, 0, 0, 0, 0, 0, 0}; | |
| static int32 current_flag [NUM_OF_DSK] = {0, 0, 0, 0, 0, 0, 0, 0}; | |
| static uint8 tracks [NUM_OF_DSK] = { MAX_TRACKS, MAX_TRACKS, MAX_TRACKS, MAX_TRACKS, | |
| MAX_TRACKS, MAX_TRACKS, MAX_TRACKS, MAX_TRACKS }; | |
| static int32 trace_flag = 0; | |
| static int32 in9_count = 0; | |
| static int32 in9_message = FALSE; | |
| static int32 dirty = FALSE; /* TRUE when buffer has unwritten data in it */ | |
| 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 warnDSK10 = 0; | |
| static int32 warnDSK11 = 0; | |
| static int32 warnDSK12 = 0; | |
| static int8 dskbuf[DSK_SECTSIZE]; /* data Buffer */ | |
| /* Altair MITS modified BOOT EPROM, fits in upper 256 byte of memory */ | |
| int32 bootrom[bootrom_size] = { | |
| 0xf3, 0x06, 0x80, 0x3e, 0x0e, 0xd3, 0xfe, 0x05, /* ff00-ff07 */ | |
| 0xc2, 0x05, 0xff, 0x3e, 0x16, 0xd3, 0xfe, 0x3e, /* ff08-ff0f */ | |
| 0x12, 0xd3, 0xfe, 0xdb, 0xfe, 0xb7, 0xca, 0x20, /* ff10-ff17 */ | |
| 0xff, 0x3e, 0x0c, 0xd3, 0xfe, 0xaf, 0xd3, 0xfe, /* ff18-ff1f */ | |
| 0x21, 0x00, 0x5c, 0x11, 0x33, 0xff, 0x0e, 0x88, /* ff20-ff27 */ | |
| 0x1a, 0x77, 0x13, 0x23, 0x0d, 0xc2, 0x28, 0xff, /* ff28-ff2f */ | |
| 0xc3, 0x00, 0x5c, 0x31, 0x21, 0x5d, 0x3e, 0x00, /* ff30-ff37 */ | |
| 0xd3, 0x08, 0x3e, 0x04, 0xd3, 0x09, 0xc3, 0x19, /* ff38-ff3f */ | |
| 0x5c, 0xdb, 0x08, 0xe6, 0x02, 0xc2, 0x0e, 0x5c, /* ff40-ff47 */ | |
| 0x3e, 0x02, 0xd3, 0x09, 0xdb, 0x08, 0xe6, 0x40, /* ff48-ff4f */ | |
| 0xc2, 0x0e, 0x5c, 0x11, 0x00, 0x00, 0x06, 0x08, /* ff50-ff57 */ | |
| 0xc5, 0xd5, 0x11, 0x86, 0x80, 0x21, 0x88, 0x5c, /* ff58-ff5f */ | |
| 0xdb, 0x09, 0x1f, 0xda, 0x2d, 0x5c, 0xe6, 0x1f, /* ff60-ff67 */ | |
| 0xb8, 0xc2, 0x2d, 0x5c, 0xdb, 0x08, 0xb7, 0xfa, /* ff68-ff6f */ | |
| 0x39, 0x5c, 0xdb, 0x0a, 0x77, 0x23, 0x1d, 0xc2, /* ff70-ff77 */ | |
| 0x39, 0x5c, 0xd1, 0x21, 0x8b, 0x5c, 0x06, 0x80, /* ff78-ff7f */ | |
| 0x7e, 0x12, 0x23, 0x13, 0x05, 0xc2, 0x4d, 0x5c, /* ff80-ff87 */ | |
| 0xc1, 0x21, 0x00, 0x5c, 0x7a, 0xbc, 0xc2, 0x60, /* ff88-ff8f */ | |
| 0x5c, 0x7b, 0xbd, 0xd2, 0x80, 0x5c, 0x04, 0x04, /* ff90-ff97 */ | |
| 0x78, 0xfe, 0x20, 0xda, 0x25, 0x5c, 0x06, 0x01, /* ff98-ff9f */ | |
| 0xca, 0x25, 0x5c, 0xdb, 0x08, 0xe6, 0x02, 0xc2, /* ffa0-ffa7 */ | |
| 0x70, 0x5c, 0x3e, 0x01, 0xd3, 0x09, 0x06, 0x00, /* ffa8-ffaf */ | |
| 0xc3, 0x25, 0x5c, 0x3e, 0x80, 0xd3, 0x08, 0xfb, /* ffb0-ffb7 */ | |
| 0xc3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* ffb8-ffbf */ | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* ffc0-ffc7 */ | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* ffc8-ffcf */ | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* ffd0-ffd7 */ | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* ffd8-ffdf */ | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* ffe0-ffe7 */ | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* ffe8-ffef */ | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* fff0-fff7 */ | |
| 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* fff8-ffff */ | |
| }; | |
| /* 88DSK Standard I/O Data Structures */ | |
| static UNIT dsk_unit[] = { | |
| { UDATA (&dsk_svc, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }, | |
| { UDATA (&dsk_svc, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }, | |
| { UDATA (&dsk_svc, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }, | |
| { UDATA (&dsk_svc, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }, | |
| { UDATA (&dsk_svc, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }, | |
| { UDATA (&dsk_svc, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }, | |
| { UDATA (&dsk_svc, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) }, | |
| { UDATA (&dsk_svc, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MAX_DSK_SIZE) } | |
| }; | |
| static REG dsk_reg[] = { | |
| { DRDATA (DISK, current_disk, 4) }, | |
| { BRDATA (CURTRACK, current_track, 10, 32, NUM_OF_DSK), REG_CIRC + REG_RO }, | |
| { BRDATA (CURSECTOR, current_sector, 10, 32, NUM_OF_DSK), REG_CIRC + REG_RO }, | |
| { BRDATA (CURBYTE, current_byte, 10, 32, NUM_OF_DSK), REG_CIRC + REG_RO }, | |
| { BRDATA (CURFLAG, current_flag, 10, 32, NUM_OF_DSK), REG_CIRC + REG_RO }, | |
| { BRDATA (TRACKS, tracks, 10, 8, NUM_OF_DSK), REG_CIRC }, | |
| { ORDATA (TRACE, trace_flag, 8) }, | |
| { DRDATA (IN9COUNT, in9_count, 4), REG_RO }, | |
| { DRDATA (IN9MESSAGE, in9_message, 4), REG_RO }, | |
| { DRDATA (DIRTY, dirty, 4), REG_RO }, | |
| { 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 (WARNDSK10, warnDSK10, 4), REG_RO }, | |
| { DRDATA (WARNDSK11, warnDSK11, 4), REG_RO }, | |
| { DRDATA (WARNDSK12, warnDSK12, 4), REG_RO }, | |
| { BRDATA (DISKBUFFER, dskbuf, 10, 8, DSK_SECTSIZE), REG_CIRC + REG_RO }, | |
| { NULL } | |
| }; | |
| static MTAB dsk_mod[] = { | |
| { UNIT_DSKWLK, 0, "write enabled", "WRITEENABLED", NULL }, | |
| { UNIT_DSKWLK, UNIT_DSKWLK, "write locked", "LOCKED", NULL }, | |
| /* quiet, no warning messages */ | |
| { UNIT_DSK_VERBOSE, 0, "QUIET", "QUIET", NULL }, | |
| /* verbose, show warning messages */ | |
| { UNIT_DSK_VERBOSE, UNIT_DSK_VERBOSE, "VERBOSE", "VERBOSE", &dsk_set_verbose }, | |
| { 0 } | |
| }; | |
| DEVICE dsk_dev = { | |
| "DSK", dsk_unit, dsk_reg, dsk_mod, | |
| 8, 10, 31, 1, 8, 8, | |
| NULL, NULL, &dsk_reset, | |
| &dsk_boot, NULL, NULL, | |
| NULL, 0, 0, | |
| NULL, NULL, NULL | |
| }; | |
| static void resetDSKWarningFlags(void) { | |
| int32 i; | |
| for (i = 0; i < NUM_OF_DSK; i++) { | |
| warnLock[i] = 0; | |
| warnAttached[i] = 0; | |
| } | |
| warnDSK10 = 0; | |
| warnDSK11 = 0; | |
| warnDSK12 = 0; | |
| } | |
| static t_stat dsk_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 (((dsk_dev.units + i) -> flags) & UNIT_DSK_VERBOSE) { | |
| return TRUE; | |
| } | |
| } | |
| return FALSE; | |
| } | |
| static char* selectInOut(const int32 io) { | |
| return io == 0 ? "IN" : "OUT"; | |
| } | |
| /* service routines to handle simulator functions */ | |
| /* service routine - actually gets char & places in buffer */ | |
| static t_stat dsk_svc(UNIT *uptr) { | |
| return SCPE_OK; | |
| } | |
| /* reset routine */ | |
| static t_stat dsk_reset(DEVICE *dptr) { | |
| resetDSKWarningFlags(); | |
| current_disk = NUM_OF_DSK; | |
| trace_flag = 0; | |
| in9_count = 0; | |
| in9_message = FALSE; | |
| return SCPE_OK; | |
| } | |
| /* The boot routine modifies the boot ROM in such a way that subsequently | |
| the specified disk is used for boot purposes. | |
| */ | |
| static t_stat dsk_boot(int32 unitno, DEVICE *dptr) { | |
| if (cpu_unit.flags & (UNIT_ALTAIRROM | UNIT_BANKED)) { | |
| if (install_bootrom()) { | |
| printf("ALTAIR boot ROM installed.\n"); | |
| } | |
| /* check whether we are really modifying an LD A,<> instruction */ | |
| if ((bootrom[unitNoOffset1 - 1] == LDAInstruction) && (bootrom[unitNoOffset2 - 1] == LDAInstruction)) { | |
| bootrom[unitNoOffset1] = unitno & 0xff; /* LD A,<unitno> */ | |
| bootrom[unitNoOffset2] = 0x80 | (unitno & 0xff); /* LD a,80h | <unitno> */ | |
| } | |
| else { /* Attempt to modify non LD A,<> instructions is refused. */ | |
| printf("Incorrect boot ROM offsets detected.\n"); | |
| return SCPE_IERR; | |
| } | |
| } | |
| saved_PC = defaultROMLow; | |
| return SCPE_OK; | |
| } | |
| /* I/O instruction handlers, called from the CPU module when an | |
| IN or OUT instruction is issued. | |
| Each function is passed an 'io' flag, where 0 means a read from | |
| the port, and 1 means a write to the port. On input, the actual | |
| input is passed as the return value, on output, 'data' is written | |
| to the device. | |
| */ | |
| /* Disk Controller Status/Select */ | |
| /* IMPORTANT: The status flags read by port 8 IN instruction are | |
| INVERTED, that is, 0 is true and 1 is false. To handle this, the | |
| simulator keeps it's own status flags as 0=false, 1=true; and | |
| returns the COMPLEMENT of the status flags when read. This makes | |
| setting/testing of the flag bits more logical, yet meets the | |
| simulation requirement that they are reversed in hardware. | |
| */ | |
| int32 dsk10(const int32 port, const int32 io, const int32 data) { | |
| int32 current_disk_flags; | |
| in9_count = 0; | |
| if (io == 0) { /* IN: return flags */ | |
| if (current_disk >= NUM_OF_DSK) { | |
| if (hasVerbose() && (warnDSK10 < warnLevelDSK)) { | |
| warnDSK10++; | |
| /*01*/ message1("Attempt of IN 0x08 on unattached disk - ignored."); | |
| } | |
| return 0xff; /* no drive selected - can do nothing */ | |
| } | |
| return (~current_flag[current_disk]) & 0xff; /* return the COMPLEMENT! */ | |
| } | |
| /* OUT: Controller set/reset/enable/disable */ | |
| if (dirty) { /* implies that current_disk < NUM_OF_DSK */ | |
| writebuf(); | |
| } | |
| if (trace_flag & TRACE_IN_OUT) { | |
| message2("OUT 0x08: %x", data); | |
| } | |
| current_disk = data & NUM_OF_DSK_MASK; /* 0 <= current_disk < NUM_OF_DSK */ | |
| current_disk_flags = (dsk_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*/message2("Attempt to select unattached DSK%d - ignored.", current_disk); | |
| } | |
| current_disk = NUM_OF_DSK; | |
| } | |
| else { | |
| current_sector[current_disk] = 0xff; /* reset internal counters */ | |
| current_byte[current_disk] = 0xff; | |
| current_flag[current_disk] = data & 0x80 ? 0 /* disable drive */ : | |
| (current_track[current_disk] == 0 ? 0x5a /* enable: head move true, track 0 if there */ : | |
| 0x1a); /* enable: head move true */ | |
| } | |
| return 0; /* ignored since OUT */ | |
| } | |
| /* Disk Drive Status/Functions */ | |
| int32 dsk11(const int32 port, const int32 io, const int32 data) { | |
| if (current_disk >= NUM_OF_DSK) { | |
| if (hasVerbose() && (warnDSK11 < warnLevelDSK)) { | |
| warnDSK11++; | |
| /*03*/ message2("Attempt of %s 0x09 on unattached disk - ignored.", selectInOut(io)); | |
| } | |
| return 0; /* no drive selected - can do nothing */ | |
| } | |
| /* now current_disk < NUM_OF_DSK */ | |
| if (io == 0) { /* read sector position */ | |
| in9_count++; | |
| if ((trace_flag & TRACE_SECTOR_STUCK) && (in9_count > 2 * DSK_SECT) && (!in9_message)) { | |
| in9_message = TRUE; | |
| message2("Looping on sector find %d.", current_disk); | |
| } | |
| if (trace_flag & TRACE_IN_OUT) { | |
| message1("IN 0x09"); | |
| } | |
| if (dirty) {/* implies that current_disk < NUM_OF_DSK */ | |
| writebuf(); | |
| } | |
| if (current_flag[current_disk] & 0x04) { /* head loaded? */ | |
| current_sector[current_disk]++; | |
| if (current_sector[current_disk] >= DSK_SECT) { | |
| current_sector[current_disk] = 0; | |
| } | |
| current_byte[current_disk] = 0xff; | |
| return (((current_sector[current_disk] << 1) & 0x3e) /* return 'sector true' bit = 0 (true) */ | |
| | 0xc0); /* set on 'unused' bits */ | |
| } else { | |
| return 0; /* head not loaded - return 0 */ | |
| } | |
| } | |
| in9_count = 0; | |
| /* drive functions */ | |
| if (trace_flag & TRACE_IN_OUT) { | |
| message2("OUT 0x09: %x", data); | |
| } | |
| if (data & 0x01) { /* step head in */ | |
| if (trace_flag & TRACE_TRACK_STUCK) { | |
| if (current_track[current_disk] == (tracks[current_disk] - 1)) { | |
| message2("Unnecessary step in for disk %d", current_disk); | |
| } | |
| } | |
| current_track[current_disk]++; | |
| if (current_track[current_disk] > (tracks[current_disk] - 1)) { | |
| current_track[current_disk] = (tracks[current_disk] - 1); | |
| } | |
| if (dirty) { /* implies that current_disk < NUM_OF_DSK */ | |
| writebuf(); | |
| } | |
| current_sector[current_disk] = 0xff; | |
| current_byte[current_disk] = 0xff; | |
| } | |
| if (data & 0x02) { /* step head out */ | |
| if (trace_flag & TRACE_TRACK_STUCK) { | |
| if (current_track[current_disk] == 0) { | |
| message2("Unnecessary step out for disk %d", current_disk); | |
| } | |
| } | |
| current_track[current_disk]--; | |
| if (current_track[current_disk] < 0) { | |
| current_track[current_disk] = 0; | |
| current_flag[current_disk] |= 0x40; /* track 0 if there */ | |
| } | |
| if (dirty) { /* implies that current_disk < NUM_OF_DSK */ | |
| writebuf(); | |
| } | |
| current_sector[current_disk] = 0xff; | |
| current_byte[current_disk] = 0xff; | |
| } | |
| if (dirty) { /* implies that current_disk < NUM_OF_DSK */ | |
| writebuf(); | |
| } | |
| if (data & 0x04) { /* head load */ | |
| current_flag[current_disk] |= 0x04; /* turn on head loaded bit */ | |
| current_flag[current_disk] |= 0x80; /* turn on 'read data available' */ | |
| } | |
| if (data & 0x08) { /* head unload */ | |
| current_flag[current_disk] &= 0xfb; /* turn off 'head loaded' bit */ | |
| current_flag[current_disk] &= 0x7f; /* turn off 'read data available' */ | |
| current_sector[current_disk] = 0xff; | |
| current_byte[current_disk] = 0xff; | |
| } | |
| /* interrupts & head current are ignored */ | |
| if (data & 0x80) { /* write sequence start */ | |
| current_byte[current_disk] = 0; | |
| current_flag[current_disk] |= 0x01; /* enter new write data on */ | |
| } | |
| return 0; /* ignored since OUT */ | |
| } | |
| /* Disk Data In/Out */ | |
| static INLINE int32 dskseek(const UNIT *xptr) { | |
| return fseek(xptr -> fileref, DSK_TRACSIZE * current_track[current_disk] + | |
| DSK_SECTSIZE * current_sector[current_disk], SEEK_SET); | |
| } | |
| int32 dsk12(const int32 port, const int32 io, const int32 data) { | |
| int32 i; | |
| UNIT *uptr; | |
| if (current_disk >= NUM_OF_DSK) { | |
| if (hasVerbose() && (warnDSK12 < warnLevelDSK)) { | |
| warnDSK12++; | |
| /*04*/ message2("Attempt of %s 0x0a on unattached disk - ignored.", selectInOut(io)); | |
| } | |
| return 0; | |
| } | |
| /* now current_disk < NUM_OF_DSK */ | |
| in9_count = 0; | |
| uptr = dsk_dev.units + current_disk; | |
| if (io == 0) { | |
| if (current_byte[current_disk] >= DSK_SECTSIZE) { | |
| /* physically read the sector */ | |
| if (trace_flag & TRACE_READ_WRITE) { | |
| message4("IN 0x0a (READ) D%d T%d S%d", current_disk, current_track[current_disk], current_sector[current_disk]); | |
| } | |
| for (i = 0; i < DSK_SECTSIZE; i++) { | |
| dskbuf[i] = 0; | |
| } | |
| dskseek(uptr); | |
| fread(dskbuf, DSK_SECTSIZE, 1, uptr -> fileref); | |
| current_byte[current_disk] = 0; | |
| } | |
| return dskbuf[current_byte[current_disk]++] & 0xff; | |
| } | |
| else { | |
| if (current_byte[current_disk] >= DSK_SECTSIZE) { | |
| writebuf(); /* from above we have that current_disk < NUM_OF_DSK */ | |
| } | |
| else { | |
| dirty = TRUE; /* this guarantees for the next call to writebuf that current_disk < NUM_OF_DSK */ | |
| dskbuf[current_byte[current_disk]++] = data & 0xff; | |
| } | |
| return 0; /* ignored since OUT */ | |
| } | |
| } | |
| /* precondition: current_disk < NUM_OF_DSK */ | |
| static void writebuf(void) { | |
| int32 i, rtn; | |
| UNIT *uptr; | |
| i = current_byte[current_disk]; /* null-fill rest of sector if any */ | |
| while (i < DSK_SECTSIZE) { | |
| dskbuf[i++] = 0; | |
| } | |
| uptr = dsk_dev.units + current_disk; | |
| if (((uptr -> flags) & UNIT_DSKWLK) == 0) { /* write enabled */ | |
| if (trace_flag & TRACE_READ_WRITE) { | |
| message4("OUT 0x0a (WRITE) D%d T%d S%d", current_disk, current_track[current_disk], current_sector[current_disk]); | |
| } | |
| if (dskseek(uptr)) { | |
| message4("fseek failed D%d T%d S%d", current_disk, current_track[current_disk], current_sector[current_disk]); | |
| } | |
| rtn = fwrite(dskbuf, DSK_SECTSIZE, 1, uptr -> fileref); | |
| if (rtn != 1) { | |
| message4("fwrite failed T%d S%d Return=%d", current_track[current_disk], current_sector[current_disk], rtn); | |
| } | |
| } | |
| else if ( ((uptr -> flags) & UNIT_DSK_VERBOSE) && (warnLock[current_disk] < warnLevelDSK) ) { | |
| /* write locked - print warning message if required */ | |
| warnLock[current_disk]++; | |
| /*05*/ message2("Attempt to write to locked DSK%d - ignored.", current_disk); | |
| } | |
| current_flag[current_disk] &= 0xfe; /* ENWD off */ | |
| current_byte[current_disk] = 0xff; | |
| dirty = FALSE; | |
| } |