| /************************************************************************* | |
| * s100_mdsa.c: North Star Single Density Controller Emulation | |
| * | |
| * Created by Mike Douglas | |
| * Based on s100_mdsad.c written by Howard Harte | |
| * | |
| * Module Description: | |
| * Northstar MDS-A Single Density Disk Controller module for SIMH | |
| * | |
| * Environment: | |
| * User mode only | |
| * | |
| *************************************************************************/ | |
| /*#define DBG_MSG*/ | |
| #include "altairz80_defs.h" | |
| #include "sim_imd.h" | |
| #if defined (_WIN32) | |
| #include <windows.h> | |
| #endif | |
| #ifdef DBG_MSG | |
| #define DBG_PRINT(args) printf args | |
| #else | |
| #define DBG_PRINT(args) | |
| #endif | |
| /* Debug flags */ | |
| #define ERROR_MSG (1 << 0) | |
| #define SEEK_MSG (1 << 1) | |
| #define CMD_MSG (1 << 2) | |
| #define RD_DATA_MSG (1 << 3) | |
| #define WR_DATA_MSG (1 << 4) | |
| #define STATUS_MSG (1 << 5) | |
| #define RD_DATA_DETAIL_MSG (1 << 6) | |
| #define WR_DATA_DETAIL_MSG (1 << 7) | |
| extern uint32 PCX; | |
| extern t_stat set_membase(UNIT *uptr, int32 val, CONST char *cptr, void *desc); | |
| extern t_stat show_membase(FILE *st, UNIT *uptr, int32 val, CONST void *desc); | |
| extern uint32 sim_map_resource(uint32 baseaddr, uint32 size, uint32 resource_type, | |
| int32 (*routine)(const int32, const int32, const int32), uint8 unmap); | |
| #define MDSA_MAX_DRIVES 3 | |
| #define MDSA_SECTOR_LEN 256 | |
| #define MDSA_SECTORS_PER_TRACK 10 | |
| #define MDSA_TRACKS 35 | |
| #define MDSA_RAW_LEN (16 + 1 + MDSA_SECTOR_LEN + 1) | |
| typedef union { | |
| struct { | |
| uint8 zeros[16]; | |
| uint8 sync[1]; | |
| uint8 data[MDSA_SECTOR_LEN]; | |
| uint8 checksum; | |
| } u; | |
| uint8 raw[MDSA_RAW_LEN]; | |
| } SECTOR_FORMAT; | |
| typedef struct { | |
| UNIT *uptr; | |
| uint8 track; | |
| uint8 wp; /* Disk write protected */ | |
| uint8 sector; /* Current Sector number */ | |
| uint32 sector_wait_count; | |
| } MDSA_DRIVE_INFO; | |
| typedef struct { | |
| uint8 sf; /* Sector Flag: set when sector hole detected, reset by software. */ | |
| uint8 wi; /* Window: true during 96-microsecond window at beginning of sector. */ | |
| uint8 mo; /* Motor On: true while motor(s) are on. */ | |
| } COM_STATUS; | |
| typedef struct { | |
| uint8 wr; /* Write: controller ready to receive write data */ | |
| uint8 bd; /* Body: set when sync character is detected. */ | |
| uint8 wp; /* Write Protect: true while the diskette installed in the selected drive is write protected. */ | |
| uint8 t0; /* Track 0: true if selected drive is at track zero. */ | |
| } A_STATUS; | |
| typedef struct { | |
| uint8 sc; /* Sector Counter: indicates the current sector position. */ | |
| } B_STATUS; | |
| typedef struct { | |
| PNP_INFO pnp; /* Plug and Play */ | |
| COM_STATUS com_status; | |
| A_STATUS a_status; | |
| B_STATUS b_status; | |
| uint8 int_enable; /* Interrupt Enable */ | |
| uint8 stepState; /* state of step flip-flop*/ | |
| uint8 stepDir; /* state of step direction flip-flop */ | |
| uint8 currentDrive; /* currently selected drive */ | |
| uint32 datacount; /* Number of data bytes transferred from controller for current sector */ | |
| MDSA_DRIVE_INFO drive[MDSA_MAX_DRIVES]; | |
| } MDSA_INFO; | |
| static MDSA_INFO mdsa_info_data = { { 0xE800, 1024, 0, 0 } }; | |
| static MDSA_INFO *mdsa_info = &mdsa_info_data; | |
| static SECTOR_FORMAT sdata; | |
| static uint32 stepCleared = TRUE; /* true when step bit has returned to zero */ | |
| #define UNIT_V_MDSA_VERBOSE (UNIT_V_UF + 1) /* verbose mode, i.e. show error messages */ | |
| #define UNIT_MDSA_VERBOSE (1 << UNIT_V_MDSA_VERBOSE) | |
| #define MDSA_CAPACITY (35*10*MDSA_SECTOR_LEN) /* Default North Star Disk Capacity */ | |
| /* MDS-AD Controller Subcases */ | |
| #define MDSA_READ_ROM0 0 | |
| #define MDSA_READ_ROM1 1 | |
| #define MDSA_WRITE_DATA 2 | |
| #define MDSA_CTLR_COMMAND 3 | |
| /* MDS_AD Controller Command Bits */ | |
| #define MDSA_MOTORS_ON 0x80 /* 1 = motor on */ | |
| #define MDSA_READ_DATA 0x40 /* 1 = return byte read from disk */ | |
| #define MDSA_B_STATUS 0x20 /* 1 = return B status, else A status */ | |
| /* MDS-AD Enumerated Controller Commands */ | |
| #define MDSA_CMD_DRIVE 0 /* select drive in M1,M0 */ | |
| #define MDSA_CMD_BEGIN_WR 1 /* start write */ | |
| #define MDSA_CMD_STEP 2 /* load step bit from M0 */ | |
| #define MDSA_CMD_INTR 3 /* load interrupt enable from M0 */ | |
| #define MDSA_CMD_NOP 4 | |
| #define MDSA_CMD_RESET_SF 5 /* reset sector flag */ | |
| #define MDSA_CMD_RESET 6 /* reset controller, raise heads, stop motors */ | |
| #define MDSA_CMD_STEP_DIR 7 /* load step direction from M0, 1=in, 0=out */ | |
| /* MDS-AD status byte masks */ | |
| /* A-Status */ | |
| #define MDSA_A_SF 0x80 | |
| #define MDSA_A_WI 0x40 | |
| #define MDSA_A_MO 0x10 | |
| #define MDSA_A_WR 0x08 | |
| #define MDSA_A_BD 0x04 | |
| #define MDSA_A_WP 0x02 | |
| #define MDSA_A_T0 0x01 | |
| /* B-Status */ | |
| #define MDSA_B_SF 0x80 | |
| #define MDSA_B_WI 0x40 | |
| #define MDSA_B_MO 0x10 | |
| #define MDSA_B_SC 0x0f | |
| /* Local function prototypes */ | |
| static t_stat mdsa_reset(DEVICE *mdsa_dev); | |
| static t_stat mdsa_attach(UNIT *uptr, CONST char *cptr); | |
| static t_stat mdsa_detach(UNIT *uptr); | |
| static t_stat mdsa_boot(int32 unitno, DEVICE *dptr); | |
| static uint8 MDSA_Read(const uint32 Addr); | |
| static const char* mdsa_description(DEVICE *dptr); | |
| static int32 mdsadev(const int32 Addr, const int32 rw, const int32 data); | |
| static UNIT mdsa_unit[] = { | |
| { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MDSA_CAPACITY) }, | |
| { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MDSA_CAPACITY) }, | |
| { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MDSA_CAPACITY) }, | |
| { UDATA (NULL, UNIT_FIX + UNIT_ATTABLE + UNIT_DISABLE + UNIT_ROABLE, MDSA_CAPACITY) } | |
| }; | |
| static REG mdsa_reg[] = { | |
| { NULL } | |
| }; | |
| #define MDSA_NAME "North Star Single Density Controller" | |
| static const char* mdsa_description(DEVICE *dptr) { | |
| return MDSA_NAME; | |
| } | |
| static MTAB mdsa_mod[] = { | |
| { MTAB_XTD|MTAB_VDV, 0, "MEMBASE", "MEMBASE", | |
| &set_membase, &show_membase, NULL, "Sets disk controller memory base address" }, | |
| /* quiet, no warning messages */ | |
| { UNIT_MDSA_VERBOSE, 0, "QUIET", "QUIET", | |
| NULL, NULL, NULL, "No verbose messages for unit " MDSA_NAME "n" }, | |
| /* verbose, show warning messages */ | |
| { UNIT_MDSA_VERBOSE, UNIT_MDSA_VERBOSE, "VERBOSE", "VERBOSE", | |
| NULL, NULL, NULL, "Verbose messages for unit " MDSA_NAME "n" }, | |
| { 0 } | |
| }; | |
| /* Debug Flags */ | |
| static DEBTAB mdsa_dt[] = { | |
| { "ERROR", ERROR_MSG, "Error messages" }, | |
| { "SEEK", SEEK_MSG, "Seek messages" }, | |
| { "CMD", CMD_MSG, "Command messages" }, | |
| { "READ", RD_DATA_MSG, "Read messages" }, | |
| { "WRITE", WR_DATA_MSG, "Write messages" }, | |
| { "STATUS", STATUS_MSG, "Status messages" }, | |
| { "RDDETAIL", RD_DATA_DETAIL_MSG, "Read detail messages" }, | |
| { "WRDETAIL", WR_DATA_DETAIL_MSG, "Write detail messags" }, | |
| { NULL, 0 } | |
| }; | |
| DEVICE mdsa_dev = { | |
| "MDSA", mdsa_unit, mdsa_reg, mdsa_mod, | |
| MDSA_MAX_DRIVES, 10, 31, 1, MDSA_MAX_DRIVES, MDSA_MAX_DRIVES, | |
| NULL, NULL, &mdsa_reset, | |
| &mdsa_boot, &mdsa_attach, &mdsa_detach, | |
| &mdsa_info_data, (DEV_DISABLE | DEV_DIS | DEV_DEBUG), ERROR_MSG, | |
| mdsa_dt, NULL, NULL, NULL, NULL, NULL, &mdsa_description | |
| }; | |
| /* Reset routine */ | |
| t_stat mdsa_reset(DEVICE *dptr) | |
| { | |
| PNP_INFO *pnp = (PNP_INFO *)dptr->ctxt; | |
| if(dptr->flags & DEV_DIS) { | |
| sim_map_resource(pnp->mem_base, pnp->mem_size, | |
| RESOURCE_TYPE_MEMORY, &mdsadev, TRUE); | |
| } else { | |
| /* Connect MDSA at base address */ | |
| if(sim_map_resource(pnp->mem_base, pnp->mem_size, | |
| RESOURCE_TYPE_MEMORY, &mdsadev, FALSE) != 0) { | |
| printf("%s: error mapping resource at 0x%04x\n", | |
| __FUNCTION__, pnp->mem_base); | |
| dptr->flags |= DEV_DIS; | |
| return SCPE_ARG; | |
| } | |
| } | |
| return SCPE_OK; | |
| } | |
| /* Attach routine */ | |
| t_stat mdsa_attach(UNIT *uptr, CONST char *cptr) | |
| { | |
| char header[4]; | |
| t_stat r; | |
| unsigned int i = 0; | |
| r = attach_unit(uptr, cptr); /* attach unit */ | |
| if(r != SCPE_OK) /* error? */ | |
| return r; | |
| /* Determine length of this disk */ | |
| if(sim_fsize(uptr->fileref) != 0) { | |
| uptr->capac = sim_fsize(uptr->fileref); | |
| } else { | |
| uptr->capac = MDSA_CAPACITY; | |
| } | |
| for(i = 0; i < MDSA_MAX_DRIVES; i++) { | |
| mdsa_info->drive[i].uptr = &mdsa_dev.units[i]; | |
| } | |
| for(i = 0; i < MDSA_MAX_DRIVES; i++) { | |
| if(mdsa_dev.units[i].fileref == uptr->fileref) { | |
| break; | |
| } | |
| } | |
| /* Default for new file is DSK */ | |
| uptr->u3 = IMAGE_TYPE_DSK; | |
| if(uptr->capac > 0) { | |
| char *rtn = fgets(header, 4, uptr->fileref); | |
| if((rtn != NULL) && (strncmp(header, "CPT", 3) == 0)) { | |
| printf("CPT images not yet supported\n"); | |
| uptr->u3 = IMAGE_TYPE_CPT; | |
| mdsa_detach(uptr); | |
| return SCPE_OPENERR; | |
| } else { | |
| uptr->u3 = IMAGE_TYPE_DSK; | |
| } | |
| } | |
| if (uptr->flags & UNIT_MDSA_VERBOSE) | |
| printf("MDSA%d, attached to '%s', type=%s, len=%d\n", i, cptr, | |
| uptr->u3 == IMAGE_TYPE_CPT ? "CPT" : "DSK", | |
| uptr->capac); | |
| return SCPE_OK; | |
| } | |
| /* Detach routine */ | |
| t_stat mdsa_detach(UNIT *uptr) | |
| { | |
| t_stat r; | |
| int8 i; | |
| for(i = 0; i < MDSA_MAX_DRIVES; i++) { | |
| if(mdsa_dev.units[i].fileref == uptr->fileref) { | |
| break; | |
| } | |
| } | |
| if (i >= MDSA_MAX_DRIVES) | |
| return SCPE_ARG; | |
| DBG_PRINT(("Detach MDSA%d\n", i)); | |
| r = detach_unit(uptr); /* detach unit */ | |
| if(r != SCPE_OK) | |
| return r; | |
| mdsa_dev.units[i].fileref = NULL; | |
| return SCPE_OK; | |
| } | |
| static t_stat mdsa_boot(int32 unitno, DEVICE *dptr) | |
| { | |
| PNP_INFO *pnp = (PNP_INFO *)dptr->ctxt; | |
| DBG_PRINT(("Booting MDSA Controller at 0x%04x" NLP, pnp->mem_base)); | |
| *((int32 *) sim_PC->loc) = pnp->mem_base; | |
| return SCPE_OK; | |
| } | |
| static int32 mdsadev(const int32 Addr, const int32 rw, const int32 data) | |
| { | |
| if(rw == 0) { /* Read */ | |
| return(MDSA_Read(Addr)); | |
| } else { /* Write */ | |
| DBG_PRINT(("MDSA: write attempt at 0x%04x ignored." NLP, Addr)); | |
| return (-1); | |
| } | |
| } | |
| /* This ROM image is taken from the ROMs on the single density controller. This is an | |
| older version of the ROM which retries forever. Newer ROMs give up after 10 tries. */ | |
| static uint8 mdsa_rom[] = { | |
| 0x31,0x14,0x21,0x3E,0x59,0x32,0x00,0x20,0x32,0x03,0x20,0x01,0x01,0x00,0x79,0x16, /* 00 */ | |
| 0x04,0x59,0x21,0x00,0x20,0xCD,0x1E,0xE9,0xC2,0x00,0xE9,0xC3,0x04,0x20,0xF5,0xE5, /* 10 */ | |
| 0xD5,0xC5,0x06,0xEB,0x3A,0x90,0xEB,0xE6,0x10,0xC2,0x34,0xE9,0x16,0x32,0xCD,0xD0, /* 20 */ | |
| 0xE9,0xC3,0x3B,0xE9,0x3A,0x03,0x20,0xB9,0xCA,0x45,0xE9,0x0A,0x79,0x32,0x03,0x20, /* 30 */ | |
| 0x16,0x0D,0xCD,0xD0,0xE9,0x21,0xFF,0x34,0x09,0xF1,0x57,0x96,0x72,0xCA,0x81,0xE9, /* 40 */ | |
| 0x21,0x1D,0xEB,0x4F,0xF2,0x65,0xE9,0x2F,0x3C,0x4F,0x3A,0x10,0xEB,0xE6,0x01,0xC2, /* 40 */ | |
| 0x81,0xE9,0x21,0x1C,0xEB,0x7E,0x3A,0x09,0xEB,0xE3,0xE3,0x3A,0x08,0xEB,0x16,0x02, /* 60 */ | |
| 0xCD,0xD0,0xE9,0x3A,0x10,0xEB,0xE6,0x01,0xCA,0x7D,0xE9,0x0E,0x01,0x0D,0xC2,0x66, /* 70 */ | |
| 0xE9,0xC1,0xCD,0xCE,0xE9,0x3A,0x30,0xEB,0xE6,0x0F,0xB8,0xC2,0x82,0xE9,0xE1,0x0D, /* 80 */ | |
| 0xFA,0x0A,0x20,0xC2,0x07,0x20,0x06,0x46,0x11,0x50,0xEB,0x0E,0x00,0x3A,0x10,0xEB, /* 90 */ | |
| 0xE6,0x04,0xC2,0xAE,0xE9,0x05,0xC2,0x9D,0xE9,0x3E,0x01,0xC1,0xB7,0xC9,0x41,0x1A, /* A0 */ | |
| 0x77,0xA8,0x07,0x47,0x23,0x0D,0xC2,0xAF,0xE9,0x1A,0xA8,0xCA,0xC4,0xE9,0x78,0x3E, /* B0 */ | |
| 0x02,0xC3,0xAB,0xE9,0xF1,0x3D,0xC8,0xF5,0xCD,0xCE,0xE9,0xC3,0x96,0xE9,0x16,0x01, /* C0 */ | |
| 0x3A,0x14,0xEB,0x3A,0x90,0xEB,0xE6,0x80,0xCA,0xD3,0xE9,0x15,0xC8,0xC3,0xD0,0xE9, /* D0 */ | |
| 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* E0 */ | |
| 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF, /* F0 */ | |
| }; | |
| static void showdata(int32 isRead) { | |
| int32 i; | |
| printf("MDSA: " ADDRESS_FORMAT " %s Sector =" NLP "\t", PCX, isRead ? "Read" : "Write"); | |
| for(i=0; i < MDSA_SECTOR_LEN; i++) { | |
| printf("%02X ", sdata.u.data[i]); | |
| if(((i+1) & 0xf) == 0) | |
| printf(NLP "\t"); | |
| } | |
| printf(NLP); | |
| } | |
| static int checksum; | |
| static uint32 sec_offset; | |
| static uint32 calculate_mdsa_sec_offset(uint8 track, uint8 sector) | |
| { | |
| return ((track * (MDSA_SECTOR_LEN * MDSA_SECTORS_PER_TRACK)) + (sector * MDSA_SECTOR_LEN)); | |
| } | |
| static uint8 MDSA_Read(const uint32 Addr) | |
| { | |
| uint8 cData; | |
| uint8 driveNum; | |
| MDSA_DRIVE_INFO *pDrive; | |
| int32 rtn; | |
| cData = 0; | |
| pDrive = &mdsa_info->drive[mdsa_info->currentDrive]; | |
| switch( (Addr & 0x300) >> 8 ) { | |
| case MDSA_READ_ROM0: /* respond to ROM at E800 or E900 */ | |
| case MDSA_READ_ROM1: | |
| cData = mdsa_rom[Addr & 0xFF]; | |
| break; | |
| case MDSA_WRITE_DATA: | |
| if(mdsa_info->datacount == 0) { | |
| sim_debug(WR_DATA_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " WRITE Start: Drive: %d, Track=%d, Sector=%d\n", | |
| PCX, mdsa_info->currentDrive, pDrive->track, pDrive->sector); | |
| sec_offset = calculate_mdsa_sec_offset(pDrive->track, pDrive->sector); | |
| } | |
| DBG_PRINT(("MDSA: " ADDRESS_FORMAT " WRITE-DATA[offset:%06x+%03x]=%02x" NLP, | |
| PCX, sec_offset, mdsa_info->datacount, Addr & 0xFF)); | |
| mdsa_info->datacount++; | |
| if(mdsa_info->datacount < MDSA_RAW_LEN) | |
| sdata.raw[mdsa_info->datacount] = Addr & 0xFF; | |
| if(mdsa_info->datacount == (MDSA_RAW_LEN - 1)) { | |
| sim_debug(WR_DATA_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT " Write Complete\n", PCX); | |
| if ((pDrive->uptr == NULL) || (pDrive->uptr->fileref == NULL)) { | |
| sim_debug(WR_DATA_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " Drive: %d not attached - write ignored.\n", PCX, mdsa_info->currentDrive); | |
| return 0x00; | |
| } | |
| if(mdsa_dev.dctrl & WR_DATA_DETAIL_MSG) | |
| showdata(FALSE); | |
| switch((pDrive->uptr)->u3) | |
| { | |
| case IMAGE_TYPE_DSK: | |
| if(pDrive->uptr->fileref == NULL) { | |
| printf(".fileref is NULL!" NLP); | |
| } else { | |
| if (sim_fseek((pDrive->uptr)->fileref, sec_offset, SEEK_SET) == 0) { | |
| sim_fwrite(sdata.u.data, 1, MDSA_SECTOR_LEN, (pDrive->uptr)->fileref); | |
| } else { | |
| printf("%s: sim_fseek error" NLP, __FUNCTION__); | |
| } | |
| } | |
| break; | |
| case IMAGE_TYPE_CPT: | |
| printf("%s: CPT Format not supported" NLP, __FUNCTION__); | |
| break; | |
| default: | |
| printf("%s: Unknown image Format" NLP, __FUNCTION__); | |
| break; | |
| } | |
| } | |
| break; | |
| case MDSA_CTLR_COMMAND: | |
| if (Addr & MDSA_MOTORS_ON) { | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT " CMD=Motors On\n", PCX); | |
| mdsa_info->com_status.mo = 1; /* Turn motors on */ | |
| } | |
| /* If read data bit is set, return data from disk and ignore command field */ | |
| if (Addr & MDSA_READ_DATA) { | |
| if(mdsa_info->datacount == 0) { | |
| sim_debug(RD_DATA_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " READ Start: Drive: %d, Track=%d, Sector=%d\n", | |
| PCX, mdsa_info->currentDrive, pDrive->track, pDrive->sector); | |
| checksum = 0; | |
| sec_offset = calculate_mdsa_sec_offset(pDrive->track, pDrive->sector); | |
| if ((pDrive->uptr == NULL) || (pDrive->uptr->fileref == NULL)) { | |
| sim_debug(RD_DATA_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " Drive: %d not attached - read ignored.\n", | |
| PCX, mdsa_info->currentDrive); | |
| return 0xe5; | |
| } | |
| switch((pDrive->uptr)->u3) { | |
| case IMAGE_TYPE_DSK: | |
| if(pDrive->uptr->fileref == NULL) { | |
| printf(".fileref is NULL!" NLP); | |
| } | |
| else { | |
| if (sim_fseek((pDrive->uptr)->fileref, sec_offset, SEEK_SET) == 0) { | |
| rtn = sim_fread(&sdata.u.data[0], 1, MDSA_SECTOR_LEN, | |
| (pDrive->uptr)->fileref); | |
| if (rtn != MDSA_SECTOR_LEN) { | |
| sim_debug(ERROR_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " READ: sim_fread error.\n", PCX); | |
| } | |
| } else { | |
| sim_debug(ERROR_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " READ: sim_fseek error.\n", PCX); | |
| } | |
| } | |
| break; | |
| case IMAGE_TYPE_CPT: | |
| printf("%s: CPT Format not supported" | |
| NLP, __FUNCTION__); | |
| break; | |
| default: | |
| printf("%s: Unknown image Format" | |
| NLP, __FUNCTION__); | |
| break; | |
| } | |
| if(mdsa_dev.dctrl & RD_DATA_DETAIL_MSG) | |
| showdata(TRUE); | |
| } | |
| if(mdsa_info->datacount < MDSA_SECTOR_LEN) { | |
| cData = sdata.u.data[mdsa_info->datacount]; | |
| /* Exclusive OR */ | |
| checksum ^= cData; | |
| /* Rotate Left Circular */ | |
| checksum = ((checksum << 1) | ((checksum & 0x80) != 0)) & 0xff; | |
| DBG_PRINT(("MDSA: " ADDRESS_FORMAT | |
| " READ-DATA[offset:%06x+%03x]=%02x" NLP, | |
| PCX, sec_offset, mdsa_info->datacount, cData)); | |
| } | |
| else { /* checksum */ | |
| cData = checksum; | |
| sim_debug(RD_DATA_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " READ-DATA: Checksum is: 0x%02x\n", | |
| PCX, cData); | |
| } | |
| mdsa_info->datacount++; | |
| } | |
| /* Not a read from disk, process the command field */ | |
| else { | |
| switch((Addr & 0x1c) >> 2) { /* switch based on 3-bit command field */ | |
| case MDSA_CMD_DRIVE: /* select drive in M1, M0 */ | |
| driveNum = Addr & 0x03; /* drive number in two lsbits */ | |
| if (driveNum == 0) /* force drive numbers to 1-3 */ | |
| driveNum++; | |
| mdsa_info->currentDrive = driveNum - 1; /* map NS drive 1-3 to 0-2 */ | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " CMD=Select Drive: Drive=%x\n", PCX, mdsa_info->currentDrive); | |
| pDrive = &mdsa_info->drive[mdsa_info->currentDrive]; | |
| mdsa_info->a_status.t0 = (pDrive->track == 0); | |
| break; | |
| case MDSA_CMD_NOP: | |
| pDrive->sector_wait_count++; | |
| switch(pDrive->sector_wait_count) { | |
| case 10: | |
| mdsa_info->com_status.sf = 1; /* new sector */ | |
| mdsa_info->com_status.wi = 1; /* in the 96us window at sector start */ | |
| mdsa_info->a_status.wr = 0; /* not ready to write */ | |
| mdsa_info->a_status.bd = 0; /* not body (not ready to read) */ | |
| pDrive->sector_wait_count = 0; | |
| pDrive->sector++; | |
| if(pDrive->sector >= MDSA_SECTORS_PER_TRACK) | |
| pDrive->sector = 0; | |
| break; | |
| case 2: /* end 96us window, set ready to write */ | |
| mdsa_info->com_status.wi = 0; | |
| mdsa_info->a_status.wr = 1; | |
| break; | |
| case 4: /* start of body - ready to read */ | |
| mdsa_info->a_status.bd = 1; | |
| break; | |
| default: | |
| break; | |
| } | |
| break; | |
| case MDSA_CMD_RESET_SF: /* reset sector flag */ | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " CMD=Reset Sector Flag\n", PCX); | |
| mdsa_info->com_status.sf = 0; | |
| mdsa_info->datacount = 0; | |
| break; | |
| case MDSA_CMD_INTR: /* load interrupt enable/disable */ | |
| mdsa_info->int_enable = Addr & 0x01; /* enable bit is M0 */ | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " CMD=Enable/Disable Interrupt: %d\n", PCX, mdsa_info->int_enable); | |
| break; | |
| case MDSA_CMD_STEP: /* load step flip-flop */ | |
| mdsa_info->stepState = Addr & 0x01; | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " CMD=Set step flip-flop to %d\n", PCX, mdsa_info->stepState); | |
| if((mdsa_info->stepState == 1) && stepCleared) { | |
| if(mdsa_info->stepDir == 0) { | |
| sim_debug(SEEK_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " Step out from track %d%s\n", PCX, pDrive->track, | |
| pDrive->track == 0 ? "[Warn: already at 0]" : ""); | |
| if(pDrive->track > 0) | |
| pDrive->track--; | |
| } | |
| else { | |
| sim_debug(SEEK_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " Step in from track %d%s\n", PCX, pDrive->track, | |
| pDrive->track == (MDSA_TRACKS - 1) ? "[Warn: already at highest track]" : ""); | |
| if(pDrive->track < (MDSA_TRACKS - 1)) | |
| pDrive->track++; | |
| } | |
| } | |
| stepCleared = (mdsa_info->stepState == 0); | |
| mdsa_info->a_status.t0 = (pDrive->track == 0); | |
| break; | |
| case MDSA_CMD_STEP_DIR: /* load step direction flip-flop*/ | |
| mdsa_info->stepDir = Addr & 0x01; /* direction is in M0 */ | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " CMD=Step direction: %s\n", PCX, mdsa_info->stepDir == 1 ? "In" : "Out"); | |
| break; | |
| case MDSA_CMD_BEGIN_WR: /* begin write */ | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " CMD=Begin Write\n", PCX); | |
| break; | |
| case MDSA_CMD_RESET: /* reset controller */ | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " CMD=Reset Controller\n", PCX); | |
| mdsa_info->com_status.mo = 0; /* Turn motors off */ | |
| break; | |
| default: | |
| sim_debug(CMD_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " Unsupported CMD=0x%x\n", PCX, Addr & 0x0F); | |
| break; | |
| } | |
| /* Return status register A or B based on the B Status bit in Addr */ | |
| cData = (mdsa_info->com_status.sf & 1) << 7; /* form common status bits */ | |
| cData |= (mdsa_info->com_status.wi & 1) << 6; | |
| cData |= (mdsa_info->com_status.mo & 1) << 4; | |
| mdsa_info->b_status.sc = pDrive->sector; | |
| if (Addr & MDSA_B_STATUS) { /* return B status register */ | |
| cData |= (mdsa_info->b_status.sc & 0x0f); | |
| sim_debug(STATUS_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " B-Status = <%s %s %s %i>\n", PCX, | |
| cData & MDSA_B_SF ? "SF" : " ", | |
| cData & MDSA_B_WI ? "WI" : " ", | |
| cData & MDSA_B_MO ? "MO" : " ", | |
| cData & MDSA_B_SC); | |
| } | |
| else { /* return A status register */ | |
| cData |= (mdsa_info->a_status.wr & 1) << 3; | |
| cData |= (mdsa_info->a_status.bd & 1) << 2; | |
| cData |= (mdsa_info->a_status.wp & 1) << 1; | |
| cData |= (mdsa_info->a_status.t0 & 1); | |
| sim_debug(STATUS_MSG, &mdsa_dev, "MDSA: " ADDRESS_FORMAT | |
| " A-Status = <%s %s %s %s %s %s %s>\n", | |
| PCX, | |
| cData & MDSA_A_SF ? "SF" : " ", | |
| cData & MDSA_A_WI ? "WI" : " ", | |
| cData & MDSA_A_MO ? "MO" : " ", | |
| cData & MDSA_A_WR ? "WR" : " ", | |
| cData & MDSA_A_BD ? "BD" : " ", | |
| cData & MDSA_A_WP ? "WP" : " ", | |
| cData & MDSA_A_T0 ? "T0" : " "); | |
| } | |
| } | |
| } | |
| return (cData); | |
| } |