/* pdp18b_sys.c: 18b PDP's simulator interface

   Copyright (c) 1993-2005, Robert M Supnik

   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
   ROBERT M SUPNIK 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 Robert M Supnik shall not be
   used in advertising or otherwise to promote the sale, use or other dealings
   in this Software without prior written authorization from Robert M Supnik.

   22-Jul-05    RMS     Removed AAS, error in V1 reference manual
   09-Jan-04    RMS     Fixed instruction table errors
   18-Oct-03    RMS     Added DECtape off reel message
   30-Jul-03    RMS     Fixed FPM class mask
   18-Jul-03    RMS     Added FP15 support
   02-Mar-03    RMS     Split loaders apart for greater flexibility
   09-Feb-03    RMS     Fixed bug in FMTASC (found by Hans Pufal)
   31-Jan-03    RMS     Added support for RB09
   05-Oct-02    RMS     Added variable device number support
   25-Jul-02    RMS     Added PDP-4 DECtape support
   10-Feb-02    RMS     Added PDP-7 DECtape IOT's
   03-Feb-02    RMS     Fixed typo (found by Robert Alan Byer)
   17-Sep-01    RMS     Removed multiconsole support
   27-May-01    RMS     Added second Teletype support
   18-May-01    RMS     Added PDP-9,-15 API IOT's
   12-May-01    RMS     Fixed bug in RIM loaders
   14-Mar-01    RMS     Added extension detection of RIM format tapes
   21-Jan-01    RMS     Added DECtape support
   30-Nov-00    RMS     Added PDP-9,-15 RIM/BIN loader format
   30-Oct-00    RMS     Added support for examine to file
   27-Oct-98    RMS     V2.4 load interface
   20-Oct-97    RMS     Fixed endian dependence in RIM loader
                        (found by Michael Somos)
*/

#include "pdp18b_defs.h"
#include <ctype.h>

extern DEVICE cpu_dev;
#if defined (PDP15)
extern DEVICE fpp_dev;
#endif
extern DEVICE ptr_dev, ptp_dev;
extern DEVICE tti_dev, tto_dev;
extern UNIT tti_unit, tto_unit;
extern DEVICE clk_dev;
#if defined (TYPE62)
extern DEVICE lp62_dev;
#endif
#if defined (TYPE647)
extern DEVICE lp647_dev;
#endif
#if defined (LP09)
extern DEVICE lp09_dev;
#endif
#if defined (LP15)
extern DEVICE lp15_dev;
#endif
extern DEVICE dt_dev;
#if defined (DRM)
extern DEVICE drm_dev;
#endif
#if defined (RB)
extern DEVICE rb_dev;
#endif
#if defined (RF)
extern DEVICE rf_dev;
#endif
#if defined (RP)
extern DEVICE rp_dev;
#endif
#if defined (MTA)
extern DEVICE mt_dev;
#endif
#if defined (TTY1)
extern DEVICE tti1_dev, tto1_dev;
extern UNIT tti1_unit, tto1_unit;
#endif
extern UNIT cpu_unit;
extern REG cpu_reg[];
extern int32 M[];
extern int32 memm;
extern int32 PC;

/* SCP data structures and interface routines

   sim_name             simulator name string
   sim_PC               pointer to saved PC register descriptor
   sim_emax             number of words for examine
   sim_devices          array of pointers to simulated devices
   sim_stop_messages    array of pointers to stop messages
   sim_load             binary loader
*/

#if defined (PDP4)
char sim_name[] = "PDP-4";
#elif defined (PDP7)
char sim_name[] = "PDP-7";
#elif defined (PDP9)
char sim_name[] = "PDP-9";
#elif defined (PDP15)
char sim_name[] = "PDP-15";
#endif

REG *sim_PC = &cpu_reg[0];

int32 sim_emax = 2;

DEVICE *sim_devices[] = {
    &cpu_dev,
#if defined (PDP15)
    &fpp_dev,
#endif
    &ptr_dev,
    &ptp_dev,
    &tti_dev,
    &tto_dev,
    &clk_dev,
#if defined (TYPE62)
    &lp62_dev,
#endif
#if defined (TYPE647)
    &lp647_dev,
#endif
#if defined (LP09)
    &lp09_dev,
#endif
#if defined (LP15)
    &lp15_dev,
#endif
#if defined (DRM)
    &drm_dev,
#endif
#if defined (RB)
    &rb_dev,
#endif
#if defined (RF)
    &rf_dev,
#endif
#if defined (RP)
    &rp_dev,
#endif
    &dt_dev,
#if defined (MTA)
    &mt_dev,
#endif
#if defined (TTY1)
    &tti1_dev, &tto1_dev,
#endif
    NULL
    };

const char *sim_stop_messages[] = {
    "Unknown error",
    "Undefined instruction",
    "HALT instruction",
    "Breakpoint",
    "Nested XCT's",
    "Invalid API interrupt",
    "Non-standard device number",
    "Memory management error",
    "FP15 instruction disabled",
    "DECtape off reel"
    };

/* Binary loaders */

int32 getword (FILE *fileref, int32 *hi)
{
int32 word, bits, st, ch;

word = st = bits = 0;
do {
    if ((ch = getc (fileref)) == EOF) return -1;
    if (ch & 0200) {
        word = (word << 6) | (ch & 077);
        bits = (bits << 1) | ((ch >> 6) & 1);
        st++;
        }
    } while (st < 3);
if (hi != NULL) *hi = bits;
return word;
}

/* PDP-4/PDP-7 RIM format loader

   Tape format
        dac addr
        data
        :
        dac addr
        data
        jmp addr or hlt
*/

t_stat rim_load_47 (FILE *fileref, char *cptr)
{
int32 origin, val;

if (*cptr != 0) return SCPE_2MARG;
origin = 0200;
for (;;) {
    if ((val = getword (fileref, NULL)) < 0) return SCPE_FMT;
    if ((val & 0760000) == 0040000) {                   /* DAC? */
        origin = val & 017777;
        if ((val = getword (fileref, NULL)) < 0) return SCPE_FMT;
        if (MEM_ADDR_OK (origin)) M[origin++] = val;
        }
    else if ((val & 0760000) == OP_JMP) {               /* JMP? */
        PC = ((origin - 1) & 060000) | (val & 017777);
        return SCPE_OK;
        }
    else if (val == OP_HLT) break;                      /* HLT? */
    else return SCPE_FMT;                               /* error */
    }
return SCPE_OK;                                         /* done */
}

/* PDP-9/15 RIM format loader

   Tape format (read in address specified externally)
        data
        :
        data
        word to execute (bit 1 of last character set)
*/

t_stat rim_load_915 (FILE *fileref, char *cptr)
{
int32 bits, origin, val;
char gbuf[CBUFSIZE];
t_stat r;

if (*cptr != 0) {                                       /* more input? */
    cptr = get_glyph (cptr, gbuf, 0);                   /* get origin */
    origin = get_uint (gbuf, 8, AMASK, &r);
    if (r != SCPE_OK) return r;
    if (*cptr != 0) return SCPE_ARG;                    /* no more */
    }
else origin = 0200;                                     /* default 200 */

for (;;) {                                              /* word loop */
    if ((val = getword (fileref, &bits)) < 0) return SCPE_FMT;
    if (bits & 1) {                                     /* end of tape? */
        if ((val & 0760000) == OP_JMP) PC = 
            ((origin - 1) & 060000) | (val & 017777);
        else if (val != OP_HLT) return SCPE_FMT;
        break;
        }
    else if (MEM_ADDR_OK (origin)) M[origin++] = val;
    }
return SCPE_OK;
}

/* PDP-9/15 BIN format loader

   BIN format (starts after RIM bootstrap)
        block/          origin (>= 0)
                        count
                        checksum
                        data
                :
                        data
        block/
        :
        endblock/       origin (< 0)
*/

t_stat bin_load_915 (FILE *fileref, char *cptr)
{
int32 i, val, bits, origin, count, cksum;

if (*cptr != 0) return SCPE_2MARG;                      /* no arguments */
do {
    val = getword (fileref, & bits);                    /* find end RIM */
    } while ((val >= 0) && ((bits & 1) == 0));
if (val < 0) rewind (fileref);                          /* no RIM? rewind */ 
for (;;) {                                              /* block loop */
    if ((val = getword (fileref, NULL)) < 0) return SCPE_FMT;
    if (val & SIGN) {
        if (val != DMASK) PC = val & 077777;
        break;
        }
    cksum = origin = val;                               /* save origin */
    if ((val = getword (fileref, NULL)) < 0) return SCPE_FMT;
    cksum = cksum + val;                                /* add to cksum */
    count = (-val) & DMASK;                             /* save count */
    if ((val = getword (fileref, NULL)) < 0) return SCPE_FMT;
    cksum = cksum + val;                                /* add to cksum */
    for (i = 0; i < count; i++) {
        if ((val = getword (fileref, NULL)) < 0) return SCPE_FMT;
        cksum = cksum + val;
        if (MEM_ADDR_OK (origin)) M[origin++] = val;
        }
    if ((cksum & DMASK) != 0) return SCPE_CSUM;
    }
return SCPE_OK;
}

#if defined (PDP4) || defined (PDP7)

/* PDP-4/PDP-7: RIM format only */

t_stat sim_load (FILE *fileref, char *cptr, char *fnam, int flag)
{
if (flag != 0) return SCPE_NOFNC;
return rim_load_47 (fileref, cptr);
}

#else

/* PDP-9/PDP-15: all formats */

t_stat sim_load (FILE *fileref, char *cptr, char *fnam, int flag)
{
extern int32 sim_switches;

if (flag != 0) return SCPE_NOFNC;
if (sim_switches & SWMASK ('S'))                        /* PDP-4/7 format? */
    return rim_load_47 (fileref, cptr);
if ((sim_switches & SWMASK ('R')) ||                    /* RIM format? */
    (match_ext (fnam, "RIM") && !(sim_switches & SWMASK ('B'))))
    return rim_load_915 (fileref, cptr);
return bin_load_915 (fileref, cptr);                    /* must be BIN */
}

#endif

/* Symbol tables */

#define I_V_FL          18                              /* inst class */
#define I_M_FL          017                             /* class mask */
#define I_V_DC          22                              /* default count */
#define I_V_NPN         0                               /* no operand */
#define I_V_NPI         1                               /* no operand IOT */
#define I_V_IOT         2                               /* IOT */
#define I_V_MRF         3                               /* memory reference */
#define I_V_OPR         4                               /* OPR */
#define I_V_LAW         5                               /* LAW */
#define I_V_XR          6                               /* index */
#define I_V_XR9         7                               /* index literal */
#define I_V_EST         8                               /* EAE setup */
#define I_V_ESH         9                               /* EAE shift */
#define I_V_EMD         10                              /* EAE mul-div */
#define I_V_FPM         11                              /* FP15 mem ref */
#define I_V_FPI         12                              /* FP15 indirect */
#define I_V_FPN         13                              /* FP15 no operand */
#define I_NPN           (I_V_NPN << I_V_FL)
#define I_NPI           (I_V_NPI << I_V_FL)
#define I_IOT           (I_V_IOT << I_V_FL)
#define I_MRF           (I_V_MRF << I_V_FL)
#define I_OPR           (I_V_OPR << I_V_FL)
#define I_LAW           (I_V_LAW << I_V_FL)
#define I_XR            (I_V_XR << I_V_FL)
#define I_XR9           (I_V_XR9 << I_V_FL)
#define I_EST           (I_V_EST << I_V_FL)
#define I_ESH           (I_V_ESH << I_V_FL)
#define I_EMD           (I_V_EMD << I_V_FL)
#define I_FPM           (I_V_FPM << I_V_FL)
#define I_FPI           (I_V_FPI << I_V_FL)
#define I_FPN           (I_V_FPN << I_V_FL)
#define MD(x) ((I_EMD) + ((x) << I_V_DC))

static const int32 masks[] = {
 0777777, 0777767, 0770000, 0760000,
 0763730, 0760000, 0777000, 0777000,
 0740700, 0760700, 0777700, 0777777,
 0777777, 0777777
 };

/* If both NPN (clear AC) and NPI versions of an IOT are defined,
   the NPN version must come first */

static const char *opcode[] = {
 "CAL", "DAC", "JMS", "DZM",                            /* mem refs */
 "LAC", "XOR", "ADD", "TAD",
 "XCT", "ISZ", "AND", "SAD",
 "JMP",

#if defined (PDP9) || defined (PDP15)                   /* mem ref ind */
 "CAL*", "DAC*", "JMS*", "DZM*",                        /* normal */
 "LAC*", "XOR*", "ADD*", "TAD*",
 "XCT*", "ISZ*", "AND*", "SAD*",
 "JMP*",
#else
 "CAL I", "DAC I", "JMS I", "DZM I",                    /* decode only */
 "LAC I", "XOR I", "ADD I", "TAD I",
 "XCT I", "ISZ I", "AND I", "SAD I",
 "JMP I",
#endif

 "LAW",                                                 /* LAW */

 "LACQ", "LACS", "ABS", "GSM", "LMQ",                   /* EAE */
 "MUL", "MULS", "DIV", "DIVS",
 "IDIV", "IDIVS", "FRDIV", "FRDIVS",
 "NORM", "NORMS",
 "MUY", "LLK MUY", "DVI", "LLK DVI",
 "NMI", "NMIS", "LRS", "LRSS",
 "LLS", "LLSS", "ALS", "ALSS",
 "EAE-setup", "EAE",                                    /* setup, general */

 "CLSF", "IOF", "ION", "CLOF", "CLON",                  /* standard IO devs */
 "RSF", "RRB", "RCF", "RSA", "RSB",
 "PSF", "PCF", "PSA", "PSB", "PLS",
 "KSF", "KRB", "KCF", "IORS", "IOOS",
 "TSF", "TCF", "TPC", "TLS",
#if defined (TYPE62)                                    /* Type 62 */
 "LPSF", "LPCF", "LPLD", "LPSE",
 "LSSF", "LSCF", "LSPR",
#endif
#if defined (TYPE647)                                   /* Type 647 */
 "LPSF", "LPCB", "LPCD", "LPCD", "LPCD",
 "LPL2", "LPLD", "LPL1",
 "LPEF", "LPCF", "LPCF", "LPCF", "LPCF",
 "LPPB", "LPLS", "LPPS",
#endif
#if defined (LP09)
 "LSDF", "LSEF", "LSCF", "LPLD",
 "LIOF", "LION",
#endif
#if defined (LP15)                                      /* LP15 */
 "LPSF", "LPPM", "LPP1", "LPDI",
 "LPRS", "LPOS", "LPEI", "LPCD", "LPCF",
#endif
#if defined (DRM)                                       /* drum */
 "DRLR", "DRLW", "DRSS", "DRCS",
 "DRSF", "DRSN", "DRCF",
 "DRLCRD", "DRLCWR", "DRLBLK", "DRCONT",
 "DRSF", "DRSOK", "DRCF",
#endif
#if defined (RB)                                        /* RB09 */
 "DBCF", "DBRD", "DBLD",
 "DBSF", "DBRS", "DBLW",
 "DBCS", "DBLM", "DBLS",
#endif
#if defined (RF)                                        /* RF09 */
 "DSSF", "DSCC", "DSCF",
 "DRBR", "DRAL", "DSFX", "DRAH",
 "DLBR", "DLAL", "DSCN", "DLAH",
 "DLOK",         "DSCD", "DSRS",
 "DGHS", "DGSS",
#endif
#if defined (RP)
 "DPSF", "DPSA", "DPSJ", "DPSE",
 "DPRSA", "DPOSA", "DPRSB", "DPOSB",
 "DPRM", "DPOM",
 "DPLA", "DPCS", "DPCA", "DPWC",
 "DPLM", "DPEM", "DPSN",
 "DPRU", "DPOU", "DPRA", "DPOA",
 "DPRC", "DPOC", "DPRW", "DPOW",
 "DPCF", "DPLZ", "DPCN", "DPLO", "DPLF",
#endif
#if defined (MTA)                                       /* TC59 */
 "MTTR", "MTCR", "MTSF", "MTRC", "MTAF",
 "MTRS", "MTGO", "MTCM", "MTLC",
#endif
#if defined (TYPE550)                                   /* Type 550 */
 "MMDF", "MMEF", "MMRD", "MMWR",
 "MMBF", "MMRS", "MMLC", "MMSE",
#elif defined (TC02)                                    /* TC02/TC15 */
 "DTCA", "DTRA", "DTXA", "DTLA",
 "DTEF", "DTRB", "DTDF",
#endif
#if defined (TTY1)
 "KSF1", "KRB1",
 "TSF1", "TCF1", "TLS1", "TCF1!TLS1",
#endif
#if defined (PDP7)
 "ITON", "TTS", "SKP7", "CAF",
 "SEM", "EEM", "EMIR", "LEM",
#endif
#if defined (PDP9)
 "SKP7", "SEM", "EEM", "LEM",
 "LPDI", "LPEI",
#endif
#if defined (PDP15)
 "SPCO", "SKP15", "RES",
 "SBA", "DBA", "EBA",
 "RDMM", "ORMM", "LDMM", "MPLR",
 "ENB", "INH", "MPRC", "IPFH",
 "PAX", "PAL", "AAC", "PXA",
 "AXS", "PXL", "PLA", "PLX",
 "CLAC","CLX", "CLLR", "AXR",

 "FPT",                                                 /* FP15 */
 "ISB", "ESB",                                          /* mem ref */
 "FSB", "URFSB", "UNFSB", "UUFSB",
 "DSB", "URDSB", "UNDSB", "UUDSB",
 "IRS", "ERS",
 "FRS", "URFRS", "UNFRS", "UUFRS",
 "DRS", "URDRS", "UNDRS", "UUDRS",
 "IMP", "EMP",
 "FMP", "URFMP", "UNFMP", "UUFMP",
 "DMP", "URDMP", "UNDMP", "UUDMP",
 "IDV", "EDV",
 "FDV", "URFDV", "UNFDV", "UUFDV",
 "DDV", "URDDV", "UNDDV", "UUDDV",
 "IRD", "ERD",
 "FRD", "URFRD", "UNFRD", "UUFRD",
 "DRD", "URDRD", "UNDRD", "UUDRD",
 "ILD", "ELD",
 "FLD", "UNFLD", "DLD", "UNDLD",
 "IST", "EST",
 "FST", "URFST", "UNFST", "UUFST",
 "DST", "UNDST",
 "ILF", "UNILF", "ELF", "UNELF",
 "FLX", "URFLX", "DLX", "URDLX",
 "ILQ", "ELQ",
 "FLQ", "UNFLQ", "DLQ", "UNDLQ",
 "LJE", "SJE",
 "IAD", "EAD",
 "FAD", "URFAD", "UNFAD", "UUFAD",
 "DAD", "URDAD", "UNDAD", "UUDAD",
 "BZA", "BMA", "BLE", "BPA",
 "BRU", "BNA", "BAC",
 "ISB*", "ESB*",                                                /* indirect */
 "FSB*", "URFSB*", "UNFSB*", "UUFSB*",
 "DSB*", "URDSB*", "UNDSB*", "UUDSB*",
 "IRS*", "ERS*",
 "FRS*", "URFRS*", "UNFRS*", "UUFRS*",
 "DRS*", "URDRS*", "UNDRS*", "UUDRS*",
 "IMP*", "EMP*",
 "FMP*", "URFMP*", "UNFMP*", "UUFMP*",
 "DMP*", "URDMP*", "UNDMP*", "UUDMP*",
 "IDV*", "EDV*",
 "FDV*", "URFDV*", "UNFDV*", "UUFDV*",
 "DDV*", "URDDV*", "UNDDV*", "UUDDV*",
 "IRD*", "ERD",
 "FRD*", "URFRD*", "UNFRD*", "UUFRD*",
 "DRD*", "URDRD*", "UNDRD*", "UUDRD*",
 "ILD*", "ELD",
 "FLD*", "UNFLD*", "DLD*", "UNDLD*",
 "IST*", "EST",
 "FST*", "URFST*", "UNFST*", "UUFST*",
 "DST*", "UNDST*",
 "ILF*", "UNILF*", "ELF*", "UNELF*",
 "FLX*", "URFLX*", "DLX*", "URDLX*",
 "ILQ*", "ELQ*",
 "FLQ*", "UNFLQ*", "DLQ*", "UNDLQ*",
 "LJE*", "SJE*",
 "IAD*", "EAD*",
 "FAD*", "URFAD*", "UNFAD*", "UUFAD*",
 "DAD*", "URDAD*", "UNDAD*", "UUDAD*",

 "FLA", "UNFLA", "FXA", "URFXA",                        /* no operand */
 "SWQ", "UNSWQ", "FZR",
 "FAB", "FNG", "FCM", "FNM",
#endif
#if defined (PDP9) || defined (PDP15)
 "MPSK", "MPSNE", "MPCV", "MPEU",
 "MPLD", "MPCNE", "PFSF",
 "TTS", "CAF", "DBK", "DBR",
 "SPI", "RPL", "ISA",
#endif
 "IOT",                                                 /* general */

 "NOP", "STL", "RCL", "RCR",
 "CLC", "LAS", "GLK",
 "OPR", "SMA", "SZA", "SZA SMA",
 "SNL", "SNL SMA", "SNL SZA", "SNL SZA SMA",
 "SKP", "SPA", "SNA", "SNA SPA",
 "SZL", "SZL SPA", "SZL SNA", "SZL SZA SPA",
 "RAL", "SMA RAL", "SZA RAL", "SZA SMA RAL",
 "SNL RAL", "SNL SMA RAL", "SNL SZA RAL", "SNL SZA SMA RAL",
 "SKP RAL", "SPA RAL", "SNA RAL", "SNA SPA RAL",
 "SZL RAL", "SZL SPA RAL", "SZL SNA RAL", "SZL SZA SPA RAL",
 "RAR", "SMA RAR", "SZA RAR", "SZA SMA RAR",
 "SNL RAR", "SNL SMA RAR", "SNL SZA RAR", "SNL SZA SMA RAR",
 "SKP RAR", "SPA RAR", "SNA RAR", "SNA SPA RAR",
 "SZL RAR", "SZL SPA RAR", "SZL SNA RAR", "SZL SZA SPA RAR",
#if defined (PDP15)
 "IAC", "SMA IAC", "SZA IAC", "SZA SMA IAC",
 "SNL IAC", "SNL SMA IAC", "SNL SZA IAC", "SNL SZA SMA IAC",
 "SKP IAC", "SPA IAC", "SNA IAC", "SNA SPA IAC",
 "SZL IAC", "SZL SPA IAC", "SZL SNA IAC", "SZL SZA SPA IAC",
#else
 "RAL RAR", "SMA RAL RAR", "SZA RAL RAR", "SZA SMA RAL RAR",
 "SNL RAL RAR", "SNL SMA RAL RAR", "SNL SZA RAL RAR", "SNL SZA SMA RAL RAR",
 "SKP RAL RAR", "SPA RAL RAR", "SNA RAL RAR", "SNA SPA RAL RAR",
 "SZL RAL RAR", "SZL SPA RAL RAR", "SZL SNA RAL RAR", "SZL SZA SPA RAL RAR",
#endif
 "RTWO", "SMA RTWO", "SZA RTWO", "SZA SMA RTWO",
 "SNL RTWO", "SNL SMA RTWO", "SNL SZA RTWO", "SNL SZA SMA RTWO",
 "SKP RTWO", "SPA RTWO", "SNA RTWO", "SNA SPA RTWO",
 "SZL RTWO", "SZL SPA RTWO", "SZL SNA RTWO", "SZL SZA SPA RTWO",
 "RTL", "SMA RTL", "SZA RTL", "SZA SMA RTL",
 "SNL RTL", "SNL SMA RTL", "SNL SZA RTL", "SNL SZA SMA RTL",
 "SKP RTL", "SPA RTL", "SNA RTL", "SNA SPA RTL",
 "SZL RTL", "SZL SPA RTL", "SZL SNA RTL", "SZL SZA SPA RTL",
 "RTR", "SMA RTR", "SZA RTR", "SZA SMA RTR",
 "SNL RTR", "SNL SMA RTR", "SNL SZA RTR", "SNL SZA SMA RTR",
 "SKP RTR", "SPA RTR", "SNA RTR", "SNA SPA RTR",
 "SZL RTR", "SZL SPA RTR", "SZL SNA RTR", "SZL SZA SPA RTR",
#if defined (PDP15)
 "BSW", "SMA BSW", "SZA BSW", "SZA SMA BSW",
 "SNL BSW", "SNL SMA BSW", "SNL SZA BSW", "SNL SZA SMA BSW",
 "SKP BSW", "SPA BSW", "SNA BSW", "SNA SPA BSW",
 "SZL BSW", "SZL SPA BSW", "SZL SNA BSW", "SZL SZA SPA BSW",
#else
 "RTL RTR", "SMA RTL RTR", "SZA RTL RTR", "SZA SMA RTL RTR",
 "SNL RTL RTR", "SNL SMA RTL RTR", "SNL SZA RTL RTR", "SNL SZA SMA RTL RTR",
 "SKP RTL RTR", "SPA RTL RTR", "SNA RTL RTR", "SNA SPA RTL RTR",
 "SZL RTL RTR", "SZL SPA RTL RTR", "SZL SNA RTL RTR", "SZL SZA SPA RTL RTR",
#endif

 "LLK", "CLQ", "LSN", "OACQ", "ECLA",                   /* encode only masks */
 "CMQ", "OMQ", "OSC", 
 "CLA", "CLL", "CML", "CMA",
 "OAS", "HLT",
 NULL
 };

static const int32 opc_val[] = {
 0000000+I_MRF, 0040000+I_MRF, 0100000+I_MRF, 0140000+I_MRF,
 0200000+I_MRF, 0240000+I_MRF, 0300000+I_MRF, 0340000+I_MRF,
 0400000+I_MRF, 0440000+I_MRF, 0500000+I_MRF, 0540000+I_MRF,
 0600000+I_MRF,
 0020000+I_MRF, 0060000+I_MRF, 0120000+I_MRF, 0160000+I_MRF,
 0220000+I_MRF, 0260000+I_MRF, 0320000+I_MRF, 0360000+I_MRF,
 0420000+I_MRF, 0460000+I_MRF, 0520000+I_MRF, 0560000+I_MRF,
 0620000+I_MRF,

 0760000+I_LAW,

 0641002+I_NPN, 0641001+I_NPN, 0644000+I_NPN, 0664000+I_NPN, 0652000+I_NPN,
 0653100+MD(022), 0657100+MD(022), 0640300+MD(023), 0644300+MD(023),
 0653300+MD(023), 0657300+MD(023), 0650300+MD(023), 0654300+MD(023),
 0640400+MD(044), 0660400+MD(044),
 0640100+I_ESH, 0660100+I_ESH, 0640300+I_ESH, 0660300+I_ESH,
 0640400+I_ESH, 0660400+I_ESH, 0640500+I_ESH, 0660500+I_ESH,
 0640600+I_ESH, 0660600+I_ESH, 0640700+I_ESH, 0660700+I_ESH,
 0640000+I_EST, 0640000+I_IOT, 

 0700001+I_NPI, 0700002+I_NPI, 0700042+I_NPI, 0700004+I_NPI, 0700044+I_NPI,
 0700101+I_NPI, 0700112+I_NPN, 0700102+I_NPI, 0700104+I_NPI, 0700144+I_NPI,
 0700201+I_NPI, 0700202+I_NPI, 0700204+I_NPI, 0700244+I_NPI, 0700206+I_NPI,
 0700301+I_NPI, 0700312+I_NPN, 0700302+I_NPI, 0700314+I_NPN, 0700304+I_NPI,
 0700401+I_NPI, 0700402+I_NPI, 0700404+I_NPI, 0700406+I_NPI,
#if defined (TYPE62)
 0706501+I_NPI, 0706502+I_NPI, 0706542+I_NPI, 0706506+I_NPI,
 0706601+I_NPI, 0706602+I_NPI, 0706606+I_NPI,
#endif
#if defined (TYPE647)
 0706501+I_NPI, 0706502+I_NPI, 0706522+I_NPI, 0706542+I_NPI, 0706562+I_NPI,
 0706526+I_NPI, 0706546+I_NPI, 0706566+I_NPI,
 0706601+I_NPI, 0706602+I_NPI, 0706622+I_NPI, 0706642+I_NPI, 0706662+I_NPI, 
 0706606+I_NPI, 0706626+I_NPI, 0706646+I_NPI,
#endif
#if defined (LP09)
 0706601+I_NPI, 0706621+I_NPI, 0706602+I_NPI, 0706622+I_NPI,
 0706604+I_NPI, 0706644+I_NPI,
#endif
#if defined (LP15)
 0706501+I_NPI, 0706521+I_NPI, 0706541+I_NPI, 0706561+I_NPI,
 0706552+I_NPN, 0706542+I_NPI, 0706544+I_NPI, 0706621+I_NPI, 0706641+I_NPI,
#endif
#if defined (DRM)
 0706006+I_NPI, 0706046+I_NPI, 0706106+I_NPI, 0706204+I_NPI,
 0706101+I_NPI, 0706201+I_NPI, 0706102+I_NPI,
 0706006+I_NPI, 0706046+I_NPI, 0706106+I_NPI, 0706204+I_NPI,
 0706101+I_NPI, 0706201+I_NPI, 0706102+I_NPI,
#endif
#if defined (RB)
 0707101+I_NPI, 0707112+I_NPN, 0707104+I_NPI,
 0707121+I_NPI, 0707132+I_NPN, 0707124+I_NPI,
 0707141+I_NPI, 0707142+I_NPI, 0707144+I_NPI,
#endif
#if defined (RF)
 0707001+I_NPI, 0707021+I_NPI, 0707041+I_NPI,
 0707002+I_NPI, 0707022+I_NPI, 0707042+I_NPI, 0707062+I_NPI,
 0707004+I_NPI, 0707024+I_NPI, 0707044+I_NPI, 0707064+I_NPI,
 0707202+I_NPI,                0707242+I_NPI, 0707262+I_NPI,
 0707204+I_NPI, 0707224+I_NPI,
#endif
#if defined (RP)
 0706301+I_NPI, 0706321+I_NPI, 0706341+I_NPI, 0706361+I_NPI,
 0706312+I_NPN, 0706302+I_NPI, 0706332+I_NPN, 0706322+I_NPI, 
 0706352+I_NPN, 0706342+I_NPI,
 0706304+I_NPI, 0706324+I_NPI, 0706344+I_NPI, 0706364+I_NPI,
 0706411+I_NPN, 0706401+I_NPI, 0706421+I_NPI,
 0706412+I_NPN, 0706402+I_NPI, 0706432+I_NPN, 0706422+I_NPI, 
 0706452+I_NPN, 0706442+I_NPI, 0706472+I_NPN, 0706462+I_NPI, 
 0706404+I_NPI, 0706424+I_NPI, 0706454+I_NPN, 0706444+I_NPI, 0706464+I_NPI,
#endif 
#if defined (MTA)
 0707301+I_NPI, 0707321+I_NPI, 0707341+I_NPI, 0707312+I_NPN, 0707322+I_NPI,
 0707352+I_NPN, 0707304+I_NPI, 0707324+I_NPI, 0707326+I_NPI, 
#endif
#if defined (TYPE550)                                   /* Type 550 */
 0707501+I_NPI, 0707541+I_NPI, 0707512+I_NPN, 0707504+I_NPI,
 0707601+I_NPI, 0707612+I_NPN, 0707604+I_NPI, 0707644+I_NPI,
#elif defined (TC02)                                    /* TC02/TC15 */
 0707541+I_NPI, 0707552+I_NPN, 0707544+I_NPI, 0707545+I_NPI,
 0707561+I_NPI, 0707572+I_NPN, 0707601+I_NPI,
#endif
#if defined (TTY1)
 0704101+I_NPI, 0704112+I_NPN,
 0704001+I_NPI, 0704002+I_NPI, 0704004+I_NPI, 0704006+I_NPI,
#endif
#if defined (PDP7)
 0703201+I_NPI, 0703301+I_NPI, 0703341+I_NPI, 0703302+I_NPI,
 0707701+I_NPI, 0707702+I_NPI, 0707742+I_NPI, 0707704+I_NPI,
#endif
#if defined (PDP9)
 0703341+I_NPI, 0707701+I_NPI, 0707702+I_NPI, 0707704+I_NPI,
 0706504+I_NPI, 0706604+I_NPI,
#endif
#if defined (PDP15)
 0703341+I_NPI, 0707741+I_NPI, 0707742+I_NPI,
 0707761+I_NPI, 0707762+I_NPI, 0707764+I_NPI,
 0700032+I_NPN, 0700022+I_NPI, 0700024+I_NPI, 0701724+I_NPI,
 0705521+I_NPI, 0705522+I_NPI, 0701722+I_NPI, 0701764+I_NPI,
 0721000+I_XR, 0722000+I_XR, 0723000+I_XR9, 0724000+I_XR,
 0725000+I_XR9, 0726000+I_XR, 0730000+I_XR, 0731000+I_XR,
 0734000+I_XR, 0735000+I_XR, 0736000+I_XR, 0737000+I_XR9,

 0710314+I_FPN,
 0710400+I_FPM, 0710500+I_FPM,
 0710440+I_FPM, 0710450+I_FPM, 0710460+I_FPM, 0710470+I_FPM,
 0710540+I_FPM, 0710550+I_FPM, 0710560+I_FPM, 0710570+I_FPM,
 0711000+I_FPM, 0711100+I_FPM,
 0711040+I_FPM, 0711050+I_FPM, 0711060+I_FPM, 0711070+I_FPM,
 0711140+I_FPM, 0711150+I_FPM, 0711160+I_FPM, 0711170+I_FPM,
 0711400+I_FPM, 0711500+I_FPM,
 0711440+I_FPM, 0711450+I_FPM, 0711460+I_FPM, 0711470+I_FPM,
 0711540+I_FPM, 0711550+I_FPM, 0711560+I_FPM, 0711570+I_FPM,
 0712000+I_FPM, 0712100+I_FPM,
 0712040+I_FPM, 0712050+I_FPM, 0712060+I_FPM, 0712070+I_FPM,
 0712140+I_FPM, 0712150+I_FPM, 0712160+I_FPM, 0712170+I_FPM,
 0712400+I_FPM, 0712500+I_FPM,
 0712440+I_FPM, 0712450+I_FPM, 0712460+I_FPM, 0712470+I_FPM,
 0712540+I_FPM, 0712550+I_FPM, 0712560+I_FPM, 0712570+I_FPM,
 0713000+I_FPM, 0713100+I_FPM,
 0713050+I_FPM, 0713070+I_FPM, 0713150+I_FPM, 0713170+I_FPM,
 0713600+I_FPM, 0713700+I_FPM,
 0713640+I_FPM, 0713650+I_FPM, 0713660+I_FPM, 0713670+I_FPM,
 0713750+I_FPM, 0713770+I_FPM,
 0714010+I_FPM, 0714030+I_FPM, 0714110+I_FPM, 0714130+I_FPM,
 0714460+I_FPM, 0714470+I_FPM, 0714560+I_FPM, 0714570+I_FPM,
 0715000+I_FPM, 0715100+I_FPM,
 0715050+I_FPM, 0715070+I_FPM, 0715150+I_FPM, 0715170+I_FPM,
 0715400+I_FPM, 0715600+I_FPM,
 0716000+I_FPM, 0716100+I_FPM,
 0716040+I_FPM, 0716050+I_FPM, 0716060+I_FPM, 0716070+I_FPM,
 0716140+I_FPM, 0716150+I_FPM, 0716160+I_FPM, 0716170+I_FPM,
 0716601+I_FPM, 0716602+I_FPM, 0716603+I_FPM,
 0716604+I_FPM, 0716606+I_FPM, 0716610+I_FPM, 0716620+I_FPM,
 0710400+I_FPI, 0710500+I_FPI,                          /* indirect */
 0710440+I_FPI, 0710450+I_FPI, 0710460+I_FPI, 0710470+I_FPI,
 0710540+I_FPI, 0710550+I_FPI, 0710560+I_FPI, 0710570+I_FPI,
 0711000+I_FPI, 0711100+I_FPI,
 0711040+I_FPI, 0711050+I_FPI, 0711060+I_FPI, 0711070+I_FPI,
 0711140+I_FPI, 0711150+I_FPI, 0711160+I_FPI, 0711170+I_FPI,
 0711400+I_FPI, 0711500+I_FPI,
 0711440+I_FPI, 0711450+I_FPI, 0711460+I_FPI, 0711470+I_FPI,
 0711540+I_FPI, 0711550+I_FPI, 0711560+I_FPI, 0711570+I_FPI,
 0712000+I_FPI, 0712100+I_FPI,
 0712040+I_FPI, 0712050+I_FPI, 0712060+I_FPI, 0712070+I_FPI,
 0712140+I_FPI, 0712150+I_FPI, 0712160+I_FPI, 0712170+I_FPI,
 0712400+I_FPI, 0712500+I_FPI,
 0712440+I_FPI, 0712450+I_FPI, 0712460+I_FPI, 0712470+I_FPI,
 0712540+I_FPI, 0712550+I_FPI, 0712560+I_FPI, 0712570+I_FPI,
 0713000+I_FPI, 0713100+I_FPI,
 0713050+I_FPI, 0713070+I_FPI, 0713150+I_FPI, 0713170+I_FPI,
 0713600+I_FPI, 0713700+I_FPI,
 0713640+I_FPI, 0713650+I_FPI, 0713660+I_FPI, 0713670+I_FPI,
 0713750+I_FPI, 0713770+I_FPI,
 0714010+I_FPI, 0714030+I_FPI, 0714110+I_FPI, 0714130+I_FPI,
 0714460+I_FPI, 0714470+I_FPI, 0714560+I_FPI, 0714570+I_FPI,
 0715000+I_FPI, 0715100+I_FPI,
 0715050+I_FPI, 0715070+I_FPI, 0715150+I_FPI, 0715170+I_FPI,
 0715400+I_FPI, 0715600+I_FPI,
 0716000+I_FPI, 0716100+I_FPI,
 0716040+I_FPI, 0716050+I_FPI, 0716060+I_FPI, 0716070+I_FPI,
 0716140+I_FPI, 0716150+I_FPI, 0716160+I_FPI, 0716170+I_FPI,
 0714210+I_FPN, 0714230+I_FPN, 0714660+I_FPN, 0714670+I_FPN,
 0715250+I_FPN, 0715270+I_FPN, 0711200+I_FPN,
 0713271+I_FPN, 0713272+I_FPN, 0713273+I_FPN, 0713250+I_FPN,
#endif
#if defined (PDP9) || defined (PDP15)
 0701701+I_NPI, 0701741+I_NPI, 0701702+I_NPI, 0701742+I_NPI,
 0701704+I_NPI, 0701744+I_NPI, 0703201+I_NPI,
 0703301+I_NPI, 0703302+I_NPI, 0703304+I_NPI, 0703344+I_NPI,
 0705501+I_NPI, 0705512+I_NPN, 0705504+I_NPI,
#endif
 0700000+I_IOT,

 0740000+I_NPN, 0744002+I_NPN, 0744010+I_NPN, 0744020+I_NPN,
 0750001+I_NPN, 0750004+I_NPN, 0750010+I_NPN,
 0740000+I_OPR, 0740100+I_OPR, 0740200+I_OPR, 0740300+I_OPR,
 0740400+I_OPR, 0740500+I_OPR, 0740600+I_OPR, 0740700+I_OPR,
 0741000+I_OPR, 0741100+I_OPR, 0741200+I_OPR, 0741300+I_OPR,
 0741400+I_OPR, 0741500+I_OPR, 0741600+I_OPR, 0741700+I_OPR,
 0740010+I_OPR, 0740110+I_OPR, 0740210+I_OPR, 0740310+I_OPR,
 0740410+I_OPR, 0740510+I_OPR, 0740610+I_OPR, 0740710+I_OPR,
 0741010+I_OPR, 0741110+I_OPR, 0741210+I_OPR, 0741310+I_OPR,
 0741410+I_OPR, 0741510+I_OPR, 0741610+I_OPR, 0741710+I_OPR,
 0740020+I_OPR, 0740120+I_OPR, 0740220+I_OPR, 0740320+I_OPR,
 0740420+I_OPR, 0740520+I_OPR, 0740620+I_OPR, 0740720+I_OPR,
 0741020+I_OPR, 0741120+I_OPR, 0741220+I_OPR, 0741320+I_OPR,
 0741420+I_OPR, 0741520+I_OPR, 0741620+I_OPR, 0741720+I_OPR,
 0740030+I_OPR, 0740130+I_OPR, 0740230+I_OPR, 0740330+I_OPR,
 0740430+I_OPR, 0740530+I_OPR, 0740630+I_OPR, 0740730+I_OPR,
 0741030+I_OPR, 0741130+I_OPR, 0741230+I_OPR, 0741330+I_OPR,
 0741430+I_OPR, 0741530+I_OPR, 0741630+I_OPR, 0741730+I_OPR,
 0742000+I_OPR, 0742100+I_OPR, 0742200+I_OPR, 0742300+I_OPR,
 0742400+I_OPR, 0742500+I_OPR, 0742600+I_OPR, 0742700+I_OPR,
 0743000+I_OPR, 0743100+I_OPR, 0743200+I_OPR, 0743300+I_OPR,
 0743400+I_OPR, 0743500+I_OPR, 0743600+I_OPR, 0743700+I_OPR,
 0742010+I_OPR, 0742110+I_OPR, 0742210+I_OPR, 0742310+I_OPR,
 0742410+I_OPR, 0742510+I_OPR, 0742610+I_OPR, 0742710+I_OPR,
 0743010+I_OPR, 0743110+I_OPR, 0743210+I_OPR, 0743310+I_OPR,
 0743410+I_OPR, 0743510+I_OPR, 0743610+I_OPR, 0743710+I_OPR,
 0742020+I_OPR, 0742120+I_OPR, 0742220+I_OPR, 0742320+I_OPR,
 0742420+I_OPR, 0742520+I_OPR, 0742620+I_OPR, 0742720+I_OPR,
 0743020+I_OPR, 0743120+I_OPR, 0743220+I_OPR, 0743320+I_OPR,
 0743420+I_OPR, 0743520+I_OPR, 0743620+I_OPR, 0743720+I_OPR,
 0742030+I_OPR, 0742130+I_OPR, 0742230+I_OPR, 0742330+I_OPR,
 0742430+I_OPR, 0742530+I_OPR, 0742630+I_OPR, 0742730+I_OPR,
 0743030+I_OPR, 0743130+I_OPR, 0743230+I_OPR, 0743330+I_OPR,
 0743430+I_OPR, 0743530+I_OPR, 0743630+I_OPR, 0743730+I_OPR,

 0660000+I_EST, 0650000+I_EST, 0644000+I_EST, 0642000+I_EST, 0641000+I_EST,
 0640004+I_EST, 0640002+I_EST, 0640001+I_EST,
 0750000+I_OPR, 0744000+I_OPR, 0740002+I_OPR, 0740001+I_OPR,
 0740004+I_OPR, 0740040+I_OPR,
 -1
 };

/* Operate or EAE decode

   Inputs:
        *of     =       output stream
        inst    =       mask bits
        class   =       instruction class code
        sp      =       space needed?
   Outputs:
        status  =       space needed?
*/

int32 fprint_opr (FILE *of, int32 inst, int32 class, int32 sp)
{
int32 i, j;

for (i = 0; opc_val[i] >= 0; i++) {                     /* loop thru ops */
    j = (opc_val[i] >> I_V_FL) & I_M_FL;                /* get class */
    if ((j == class) && (opc_val[i] & inst)) {          /* same class? */
        inst = inst & ~opc_val[i];                      /* mask bit set? */
        fprintf (of, (sp? " %s": "%s"), opcode[i]);
        sp = 1;
        }
    }
return sp;
}

/* Symbolic decode

   Inputs:
        *of     =       output stream
        addr    =       current PC
        *val    =       pointer to values
        *uptr   =       pointer to unit
        sw      =       switches
   Outputs:
        return  =       status code
*/

#define FMTASC(x) (((x) < 040)? "<%03o>": "%c"), (x)
#define SIXTOASC(x) (((x) >= 040)? (x): ((x) + 0100))

t_stat fprint_sym (FILE *of, t_addr addr, t_value *val,
    UNIT *uptr, int32 sw)
{
int32 cflag, i, j, k, sp, inst, disp, ma;

inst = val[0];
cflag = (uptr == NULL) || (uptr == &cpu_unit);
if (sw & SWMASK ('A')) {                                /* ASCII? */
    if (inst > 0377) return SCPE_ARG;
    fprintf (of, FMTASC (inst & 0177));
    return SCPE_OK;
    }
if (sw & SWMASK ('C')) {                                /* character? */
    fprintf (of, "%c", SIXTOASC ((inst >> 12) & 077));
    fprintf (of, "%c", SIXTOASC ((inst >> 6) & 077));
    fprintf (of, "%c", SIXTOASC (inst & 077));
    return SCPE_OK;
    }
#if defined (PDP15)
if (sw & SWMASK ('P')) {                                /* packed ASCII? */
    i = val[1];
    fprintf (of, FMTASC ((inst >> 11) & 0177));
    fprintf (of, FMTASC ((inst >> 4) & 0177));
    fprintf (of, FMTASC (((inst << 3) | (i >> 15)) & 0177));
    fprintf (of, FMTASC ((i >> 8) & 0177));
    fprintf (of, FMTASC ((i >> 1) & 0177));
    return -1;
    }
#endif
if (!(sw & SWMASK ('M'))) return SCPE_ARG;

/* Instruction decode */

for (i = 0; opc_val[i] >= 0; i++) {                     /* loop thru ops */
    j = (opc_val[i] >> I_V_FL) & I_M_FL;                /* get class */
    if ((opc_val[i] & DMASK) == (inst & masks[j])) {    /* match? */

        switch (j) {                                    /* case on class */

        case I_V_NPN:                                   /* no operands */
        case I_V_XR:                                    /* index no opers */
            fprintf (of, "%s", opcode[i]);              /* opcode */
            break;

        case I_V_NPI:                                   /* IOT no operand */
            fprintf (of, "%s", opcode[i]);              /* opcode */
            if (inst & 010) fprintf (of, " +10");
            break;

        case I_V_IOT:                                   /* IOT or EAE */
            fprintf (of, "%s %-o", opcode[i], inst & 037777);
            break;

        case I_V_MRF:                                   /* mem ref */
#if defined (PDP15)
            if (memm) {
                disp = inst & B_DAMASK;  
                ma = (addr & (AMASK & ~B_DAMASK)) | disp;
                }
            else {
                disp = inst & P_DAMASK;
                ma = (addr & (AMASK & ~P_DAMASK)) | disp;
                }
            fprintf (of, "%s %-o", opcode[i], (cflag? ma & AMASK: disp));
            if (!memm && (inst & I_IDX)) fprintf (of, ",X");
#else
            disp = inst & B_DAMASK;
            ma = (addr & (AMASK & ~B_DAMASK)) | disp;
            fprintf (of, "%s %-o", opcode[i], (cflag? ma & AMASK: disp));
#endif
            break;

        case I_V_OPR:                                   /* operate */
            if (sp = (inst & 03730)) fprintf (of, "%s", opcode[i]);
            fprint_opr (of, inst & 014047, I_V_OPR, sp);
            break;

        case I_V_LAW:                                   /* LAW */
            fprintf (of, "%s %-o", opcode[i], inst & 017777);
            break;

        case I_V_XR9:                                   /* index with lit */
            disp = inst & 0777;
            if (disp & 0400) fprintf (of, "%s -%-o", opcode[i], 01000 - disp);
            else fprintf (of, "%s %-o", opcode[i], disp);
            break;

        case I_V_EST:                                   /* EAE setup */
            fprint_opr (of, inst & 037007, I_V_EST, 0);
            break;

        case I_V_ESH:                                   /* EAE shift */
            sp = fprint_opr (of, inst & 017000, I_V_EST, 0);
            fprintf (of, (sp? " %s %-o": "%s %-o"), opcode[i], inst & 077);
            break;

        case I_V_EMD:                                   /* EAE mul-div */
            disp = inst & 077;                          /* get actual val */
            k = (opc_val[i] >> I_V_DC) & 077;           /* get default val */
            if (disp == k) fprintf (of, "%s", opcode[i]);
            else if (disp < k) fprintf (of, "%s -%-o", opcode[i], k - disp);
            else fprintf (of, "%s +%-o", opcode[i], disp - k);
            break;

        case I_V_FPM: case I_V_FPI:                     /* FP15 mem ref */
            fprintf (of, "%s", opcode[i]);
            if (val[1] & SIGN) fputc ('*', of);
            fprintf (of, " %-o", val[1] & ~SIGN);
            return -1;

        case I_V_FPN:                                   /* FP15 no operand */
            fprintf (of, "%s", opcode[i]);
            return -1;
            }                                           /* end case */
        return SCPE_OK;
        }                                               /* end if */
    }                                                   /* end for */
return SCPE_ARG;
}

/* Get 18b signed number

   Inputs:
        *cptr   =       pointer to input string
        *sign   =       pointer to sign
        *status =       pointer to error status
   Outputs:
        val     =       output value
*/

t_value get_sint (char *cptr, int32 *sign, t_stat *status)
{
*sign = 0;
if (*cptr == '+') {
    *sign = 1;
    cptr++;
    }
else if (*cptr == '-') {
    *sign = -1;
    cptr++;
    }
return get_uint (cptr, 8, 0777777, status);
}

/* Symbolic input

   Inputs:
        *cptr   =       pointer to input string
        addr    =       current PC
        uptr    =       pointer to unit
        *val    =       pointer to output values
        sw      =       switches
   Outputs:
        status  =       error status
*/

t_stat parse_sym (char *cptr, t_addr addr, UNIT *uptr, t_value *val, int32 sw)
{
int32 cflag, d, i, j, k, sign, damask, epcmask;
t_stat r, sta = SCPE_OK;
char gbuf[CBUFSIZE];

cflag = (uptr == NULL) || (uptr == &cpu_unit);
while (isspace (*cptr)) cptr++;
for (i = 1; (i < 5) && (cptr[i] != 0); i++)
    if (cptr[i] == 0) for (j = i + 1; j <= 5; j++) cptr[j] = 0;
if ((sw & SWMASK ('A')) || ((*cptr == '\'') && cptr++)) { /* ASCII char? */
    if (cptr[0] == 0) return SCPE_ARG;                  /* must have 1 char */
    val[0] = (t_value) cptr[0] | 0200;
    return SCPE_OK;
    }
if ((sw & SWMASK ('C')) || ((*cptr == '"') && cptr++)) { /* sixbit string? */
    if (cptr[0] == 0) return SCPE_ARG;                  /* must have 1 char */
    val[0] = (((t_value) cptr[0] & 077) << 12) |
             (((t_value) cptr[1] & 077) << 6) |
              ((t_value) cptr[2] & 077);
    return SCPE_OK;
    }
#if defined (PDP15)
if ((sw & SWMASK ('P')) || ((*cptr == '#') && cptr++)) { /* packed string? */
    if (cptr[0] == 0) return SCPE_ARG;                  /* must have 1 char */
    val[0] = (((t_value) cptr[0] & 0177) << 11) |
             (((t_value) cptr[1] & 0177) << 4) |
             (((t_value) cptr[2] & 0170) >> 3);
    val[1] = (((t_value) cptr[2] & 0007) << 15) |
             (((t_value) cptr[3] & 0177) << 8) |
             (((t_value) cptr[4] & 0177) << 1);
    return -1;
    }
#endif

cptr = get_glyph (cptr, gbuf, 0);                       /* get opcode */
for (i = 0; (opcode[i] != NULL) && (strcmp (opcode[i], gbuf) != 0) ; i++) ;
if (opcode[i] == NULL) return SCPE_ARG;
val[0] = opc_val[i] & DMASK;                            /* get value */
j = (opc_val[i] >> I_V_FL) & I_M_FL;                    /* get class */

switch (j) {                                            /* case on class */

    case I_V_XR:                                        /* index */
        break;

    case I_V_XR9:                                       /* index literal */
        cptr = get_glyph (cptr, gbuf, 0);               /* get next field */
        d = get_sint (gbuf, &sign, &r);
        if (r != SCPE_OK) return SCPE_ARG;
        if (((sign >= 0) && (d > 0377)) || ((sign < 0) && (d > 0400)))
            return SCPE_ARG;
        val[0] = val[0] | ((sign >= 0)? d: (01000 - d));
        break;

    case I_V_LAW:                                       /* law */
        cptr = get_glyph (cptr, gbuf, 0);               /* get next field */
        d = get_uint (gbuf, 8, 017777, &r);
        if (r != SCPE_OK) return SCPE_ARG;
        val[0] = val[0] | d;
        break;

    case I_V_MRF:                                       /* mem ref */
#if defined (PDP15)
        if (memm) damask = B_DAMASK;
        else damask = P_DAMASK;
        cptr = get_glyph (cptr, gbuf, ',');             /* get glyph */
#else
        damask = B_DAMASK;
        cptr = get_glyph (cptr, gbuf, 0);               /* get next field */
#endif
#if defined (PDP4) || defined (PDP7)
        if (strcmp (gbuf, "I") == 0) {                  /* indirect? */
            val[0] = val[0] | I_IND;
            cptr = get_glyph (cptr, gbuf, 0);
            }
#endif
        epcmask = AMASK & ~damask;                      /* get ePC */
        d = get_uint (gbuf, 8, AMASK, &r);              /* get addr */
        if (r != SCPE_OK) return SCPE_ARG;
        if (d <= damask) val[0] = val[0] | d;           /* fit in 12/13b? */
        else if (cflag && (((addr ^ d) & epcmask) == 0))
            val[0] = val[0] | (d & damask);             /* hi bits = ePC? */
        else return SCPE_ARG;
#if defined (PDP15)
        if (!memm) {
            cptr = get_glyph (cptr, gbuf, 0);
            if (gbuf[0] != 0) {
                if (strcmp (gbuf, "X") != 0) return SCPE_ARG;
                val[0] = val[0] | I_IDX;
                }
            }
#endif
        break;

    case I_V_EMD:                                       /* or'able */
        val[0] = val[0] | ((opc_val[i] >> I_V_DC) & 077); /* default shift */
    case I_V_EST: case I_V_ESH: 
    case I_V_NPN: case I_V_NPI:
    case I_V_IOT: case I_V_OPR:
        for (cptr = get_glyph (cptr, gbuf, 0); gbuf[0] != 0;
                cptr = get_glyph (cptr, gbuf, 0)) {
            for (i = 0; (opcode[i] != NULL) &&
                        (strcmp (opcode[i], gbuf) != 0) ; i++) ;
            if (opcode[i] != NULL) {
                k = opc_val[i] & DMASK;
                if (((k ^ val[0]) & 0740000) != 0) return SCPE_ARG;
                val[0] = val[0] | k;
                }
            else {
                d = get_sint (gbuf, & sign, &r);
                if (r != SCPE_OK) return SCPE_ARG;
                if (sign > 0) val[0] = val[0] + d;  
                else if (sign < 0) val[0] = val[0] - d;
                else val[0] = val[0] | d;
                }
            }
        break;

    case I_V_FPM:                                       /* FP15 mem ref */
        cptr = get_glyph (cptr, gbuf, 0);               /* get next field */
        val[1] = get_uint (gbuf, 8, AMASK, &r);         /* get addr */
        if (r != SCPE_OK) return SCPE_ARG;
        sta = -1;
        break;

    case I_V_FPI:                                       /* FP15 ind mem ref */
        cptr = get_glyph (cptr, gbuf, 0);               /* get next field */
        val[1] = get_uint (gbuf, 8, AMASK, &r) | SIGN;  /* get @addr */
        if (r != SCPE_OK) return SCPE_ARG;
        sta = -1;
        break;

    case I_V_FPN:                                       /* FP15 no operand */
        val[1] = 0;
        sta = -1;
        break;
        }                                               /* end case */

if (*cptr != 0) return SCPE_ARG;                        /* junk at end? */
return sta;
}
