/* pdp8_sys.c: PDP-8 simulator interface

   Copyright (c) 1993-2008, 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.

   24-Jun-08    RMS     Fixed bug in new rim loader (found by Don North)
   24-May-08    RMS     Fixed signed/unsigned declaration inconsistency
   03-Sep-07    RMS     Added FPP8 support
                        Rewrote rim and binary loaders
   15-Dec-06    RMS     Added TA8E support, IOT disambiguation
   30-Oct-06    RMS     Added infinite loop stop
   18-Oct-06    RMS     Re-ordered device list
   17-Oct-03    RMS     Added TSC8-75, TD8E support, DECtape off reel message
   25-Apr-03    RMS     Revised for extended file support
   30-Dec-01    RMS     Revised for new TTX
   26-Nov-01    RMS     Added RL8A support
   17-Sep-01    RMS     Removed multiconsole support
   16-Sep-01    RMS     Added TSS/8 packed char support, added KL8A support
   27-May-01    RMS     Added multiconsole support
   18-Mar-01    RMS     Added DF32 support
   14-Mar-01    RMS     Added extension detection of RIM binary tapes
   15-Feb-01    RMS     Added DECtape support
   30-Oct-00    RMS     Added support for examine to file
   27-Oct-98    RMS     V2.4 load interface
   10-Apr-98    RMS     Added RIM loader support
   17-Feb-97    RMS     Fixed bug in handling of bin loader fields
*/

#include "pdp8_defs.h"
#include <ctype.h>

extern DEVICE cpu_dev;
extern UNIT cpu_unit;
extern DEVICE tsc_dev;
extern DEVICE ptr_dev, ptp_dev;
extern DEVICE tti_dev, tto_dev;
extern DEVICE clk_dev, lpt_dev;
extern DEVICE rk_dev, rl_dev;
extern DEVICE rx_dev;
extern DEVICE df_dev, rf_dev;
extern DEVICE dt_dev, td_dev;
extern DEVICE mt_dev, ct_dev;
extern DEVICE ttix_dev, ttox_dev;
extern REG cpu_reg[];
extern uint16 M[];
extern int32 sim_switches;

t_stat fprint_sym_fpp (FILE *of, t_value *val);
t_stat parse_sym_fpp (char *cptr, t_value *val);
char *parse_field (char *cptr, uint32 max, uint32 *val, uint32 c);
char *parse_fpp_xr (char *cptr, uint32 *xr, t_bool inc);
int32 test_fpp_addr (uint32 ad, uint32 max);

/* SCP data structures and interface routines

   sim_name             simulator name string
   sim_PC               pointer to saved PC register descriptor
   sim_emax             maximum number of words for examine/deposit
   sim_devices          array of pointers to simulated devices
   sim_consoles         array of pointers to consoles (if more than one)
   sim_stop_messages    array of pointers to stop messages
   sim_load             binary loader
*/

char sim_name[] = "PDP-8";

REG *sim_PC = &cpu_reg[0];

int32 sim_emax = 4;

DEVICE *sim_devices[] = {
    &cpu_dev,
    &tsc_dev,
    &clk_dev,
    &ptr_dev,
    &ptp_dev,
    &tti_dev,
    &tto_dev,
    &ttix_dev,
    &ttox_dev,
    &lpt_dev,
    &rk_dev,
    &rl_dev,
    &rx_dev,
    &df_dev,
    &rf_dev,
    &dt_dev,
    &td_dev,
    &mt_dev,
    &ct_dev,
    NULL
    };

const char *sim_stop_messages[] = {
    "Unknown error",
    "Unimplemented instruction",
    "HALT instruction",
    "Breakpoint",
    "Non-standard device number",
    "DECtape off reel",
    "Infinite loop"
    };

/* Ambiguous device list - these devices have overlapped IOT codes */

DEVICE *amb_dev[] = {
    &rl_dev,
    &ct_dev,
    &td_dev,
    NULL
    };

#define AMB_RL      (1 << 12)
#define AMB_CT      (2 << 12)
#define AMB_TD      (3 << 12)

/* RIM loader format consists of alternating pairs of addresses and 12-bit
   words.  It can only operate in field 0 and is not checksummed.
*/

t_stat sim_load_rim (FILE *fi)
{
int32 origin, hi, lo, wd;

origin = 0200;
do {                                                    /* skip leader */
    if ((hi = getc (fi)) == EOF)
        return SCPE_FMT;
    } while ((hi == 0) || (hi >= 0200));
do {                                                    /* data block */
    if ((lo = getc (fi)) == EOF)
        return SCPE_FMT;
    wd = (hi << 6) | lo;
    if (wd > 07777)
        origin = wd & 07777;
    else M[origin++ & 07777] = wd;
    if ((hi = getc (fi)) == EOF)
        return SCPE_FMT;
    } while (hi < 0200);                                /* until trailer */
return SCPE_OK;
}

/* BIN loader format consists of a string of 12-bit words (made up from
   7-bit characters) between leader and trailer (200).  The last word on
   tape is the checksum.  A word with the "link" bit set is a new origin;
   a character > 0200 indicates a change of field.
*/

int32 sim_bin_getc (FILE *fi, uint32 *newf)
{
int32 c, rubout;

rubout = 0;                                             /* clear toggle */
while ((c = getc (fi)) != EOF) {                        /* read char */
    if (rubout)                                         /* toggle set? */
        rubout = 0;                                     /* clr, skip */
    else if (c == 0377)                                 /* rubout? */
        rubout = 1;                                     /* set, skip */
    else if (c > 0200)                                  /* channel 8 set? */
        *newf = (c & 070) << 9;                         /* change field */
    else return c;                                      /* otherwise ok */
    }
return EOF;
}

t_stat sim_load_bin (FILE *fi)
{
int32 hi, lo, wd, csum, t;
uint32 field, newf, origin;

do {                                                    /* skip leader */
    if ((hi = sim_bin_getc (fi, &newf)) == EOF)
        return SCPE_FMT;
    } while ((hi == 0) || (hi >= 0200));
csum = origin = field = newf = 0;                       /* init */
for (;;) {                                              /* data blocks */
    if ((lo = sim_bin_getc (fi, &newf)) == EOF)         /* low char */
        return SCPE_FMT;
    wd = (hi << 6) | lo;                                /* form word */
    t = hi;                                             /* save for csum */
    if ((hi = sim_bin_getc (fi, &newf)) == EOF)         /* next char */
        return SCPE_FMT;
    if (hi == 0200) {                                   /* end of tape? */
        if ((csum - wd) & 07777)                        /* valid csum? */
            return SCPE_CSUM;
        return SCPE_OK;
        }
    csum = csum + t + lo;                               /* add to csum */
    if (wd > 07777)                                     /* chan 7 set? */
        origin = wd & 07777;                            /* new origin */
    else {                                              /* no, data */
        if ((field | origin) >= MEMSIZE) 
            return SCPE_NXM;
        M[field | origin] = wd;
        origin = (origin + 1) & 07777;
        }
    field = newf;                                       /* update field */
    }
return SCPE_IERR;
}

/* Binary loader
   Two loader formats are supported: RIM loader (-r) and BIN (-b) loader. */

t_stat sim_load (FILE *fileref, char *cptr, char *fnam, int flag)
{
if ((*cptr != 0) || (flag != 0))
    return SCPE_ARG;
if ((sim_switches & SWMASK ('R')) ||                    /* RIM format? */
    (match_ext (fnam, "RIM") && !(sim_switches & SWMASK ('B'))))
    return sim_load_rim (fileref);
else return sim_load_bin (fileref);                     /* no, BIN */
}

/* Symbol tables */

#define I_V_FL          18                              /* flag start */
#define I_M_FL          07                              /* flag mask */
#define I_V_NPN         0                               /* no operand */
#define I_V_FLD         1                               /* field change */
#define I_V_MRF         2                               /* mem ref */
#define I_V_IOT         3                               /* general IOT */
#define I_V_OP1         4                               /* operate 1 */
#define I_V_OP2         5                               /* operate 2 */
#define I_V_OP3         6                               /* operate 3 */
#define I_V_IOA         7                               /* ambiguous IOT */
#define I_NPN           (I_V_NPN << I_V_FL)
#define I_FLD           (I_V_FLD << I_V_FL)
#define I_MRF           (I_V_MRF << I_V_FL)
#define I_IOT           (I_V_IOT << I_V_FL)
#define I_OP1           (I_V_OP1 << I_V_FL)
#define I_OP2           (I_V_OP2 << I_V_FL)
#define I_OP3           (I_V_OP3 << I_V_FL)
#define I_IOA           (I_V_IOA << I_V_FL)

static const int32 masks[] = {
    07777, 07707, 07000, 07000,
    07416, 07571, 017457, 077777,
    };

/* Ambiguous device mnemonics must precede default mnemonics */

static const char *opcode[] = {
 "SKON", "ION", "IOF", "SRQ",                           /* std IOTs */
 "GTF", "RTF", "SGT", "CAF",
 "RPE", "RSF", "RRB", "RFC", "RFC RRB",                 /* reader/punch */
 "PCE", "PSF", "PCF", "PPC", "PLS",
 "KCF", "KSF", "KCC", "KRS", "KIE", "KRB",              /* console */
 "TLF", "TSF", "TCF", "TPC", "SPI", "TLS",
 "SBE", "SPL", "CAL",                                   /* power fail */
 "CLEI", "CLDI", "CLSC", "CLLE", "CLCL", "CLSK",        /* clock */
 "CINT", "RDF", "RIF", "RIB",                           /* mem mmgt */
 "RMF", "SINT", "CUF", "SUF",
 "RLDC", "RLSD", "RLMA", "RLCA",                        /* RL - ambiguous */
 "RLCB", "RLSA", "RLWC",
 "RRER", "RRWC", "RRCA", "RRCB",
 "RRSA", "RRSI", "RLSE",
 "KCLR", "KSDR", "KSEN", "KSBF",                        /* CT - ambiguous */
 "KLSA", "KSAF", "KGOA", "KRSB",
 "SDSS", "SDST", "SDSQ",                                /* TD - ambiguous */
 "SDLC", "SDLD", "SDRC", "SDRD",
 "ADCL", "ADLM", "ADST", "ADRB",                        /* A/D */
 "ADSK", "ADSE", "ADLE", "ADRS",
 "DCMA", "DMAR", "DMAW",                                /* DF/RF */
 "DCIM", "DSAC", "DIML", "DIMA",
 "DCEA",         "DEAL", "DEAC",
 "DFSE", "DFSC", "DISK", "DMAC",
 "DCXA", "DXAL", "DXAC",
 "PSKF", "PCLF", "PSKE",                                /* LPT */
 "PSTB", "PSIE", "PCLF PSTB", "PCIE",
 "LWCR", "CWCR", "LCAR",                                /* MT */
 "CCAR", "LCMR", "LFGR", "LDBR",
 "RWCR", "CLT", "RCAR",
 "RMSR", "RCMR", "RFSR", "RDBR",
 "SKEF", "SKCB", "SKJD", "SKTR", "CLF",
 "DSKP", "DCLR", "DLAG",                                /* RK */
 "DLCA", "DRST", "DLDC", "DMAN",
 "LCD", "XDR", "STR",                                   /* RX */
 "SER", "SDN", "INTR", "INIT",
 "DTRA", "DTCA", "DTXA", "DTLA",                        /* DT */
 "DTSF", "DTRB", "DTLB",
 "ETDS", "ESKP", "ECTF", "ECDF",                        /* TSC75 */
 "ERTB", "ESME", "ERIOT", "ETEN",
 "FFST", "FPINT", "FPICL", "FPCOM",                     /* FPP8 */
 "FPHLT", "FPST", "FPRST", "FPIST",
        "FMODE",        "FMRB",
 "FMRP", "FMDO",        "FPEP",

 "CDF", "CIF", "CIF CDF",
 "AND", "TAD", "ISZ", "DCA", "JMS", "JMP", "IOT",
 "NOP", "NOP2", "NOP3", "SWAB", "SWBA",
 "STL", "GLK", "STA", "LAS", "CIA",
 "BSW", "RAL", "RTL", "RAR", "RTR", "RAL RAR", "RTL RTR",
 "SKP", "SNL", "SZL",
 "SZA", "SNA", "SZA SNL", "SNA SZL",
 "SMA", "SPA", "SMA SNL", "SPA SZL",
 "SMA SZA", "SPA SNA", "SMA SZA SNL", "SPA SNA SZL",
 "SCL", "MUY", "DVI", "NMI", "SHL", "ASR", "LSR",
 "SCA", "SCA SCL", "SCA MUY", "SCA DVI",
 "SCA NMI", "SCA SHL", "SCA ASR", "SCA LSR",
 "ACS", "MUY", "DVI", "NMI", "SHL", "ASR", "LSR",
 "SCA", "DAD", "DST", "SWBA",
 "DPSZ", "DPIC", "DCIM", "SAM",
 "CLA", "CLL", "CMA", "CML", "IAC",                     /* encode only */
 "CLA", "OAS", "HLT",
 "CLA", "MQA", "MQL",
 NULL, NULL, NULL, NULL,                                /* decode only */
 NULL
 };
 
static const int32 opc_val[] = {
 06000+I_NPN, 06001+I_NPN, 06002+I_NPN, 06003+I_NPN,
 06004+I_NPN, 06005+I_NPN, 06006+I_NPN, 06007+I_NPN,
 06010+I_NPN, 06011+I_NPN, 06012+I_NPN, 06014+I_NPN, 06016+I_NPN,
 06020+I_NPN, 06021+I_NPN, 06022+I_NPN, 06024+I_NPN, 06026+I_NPN,
 06030+I_NPN, 06031+I_NPN, 06032+I_NPN, 06034+I_NPN, 06035+I_NPN, 06036+I_NPN,
 06040+I_NPN, 06041+I_NPN, 06042+I_NPN, 06044+I_NPN, 06045+I_NPN, 06046+I_NPN,
 06101+I_NPN, 06102+I_NPN, 06103+I_NPN,
 06131+I_NPN, 06132+I_NPN, 06133+I_NPN, 06135+I_NPN, 06136+I_NPN, 06137+I_NPN,
 06204+I_NPN, 06214+I_NPN, 06224+I_NPN, 06234+I_NPN,
 06244+I_NPN, 06254+I_NPN, 06264+I_NPN, 06274+I_NPN,
 06600+I_IOA+AMB_RL, 06601+I_IOA+AMB_RL, 06602+I_IOA+AMB_RL, 06603+I_IOA+AMB_RL,
 06604+I_IOA+AMB_RL, 06605+I_IOA+AMB_RL, 06607+I_IOA+AMB_RL,
 06610+I_IOA+AMB_RL, 06611+I_IOA+AMB_RL, 06612+I_IOA+AMB_RL, 06613+I_IOA+AMB_RL,
 06614+I_IOA+AMB_RL, 06615+I_IOA+AMB_RL, 06617+I_IOA+AMB_RL,
 06700+I_IOA+AMB_CT, 06701+I_IOA+AMB_CT, 06702+I_IOA+AMB_CT, 06703+I_IOA+AMB_CT,
 06704+I_IOA+AMB_CT, 06705+I_IOA+AMB_CT, 06706+I_IOA+AMB_CT, 06707+I_IOA+AMB_CT,
 06771+I_IOA+AMB_TD, 06772+I_IOA+AMB_TD, 06773+I_IOA+AMB_TD,
 06774+I_IOA+AMB_TD, 06775+I_IOA+AMB_TD, 06776+I_IOA+AMB_TD, 06777+I_IOA+AMB_TD,
 06530+I_NPN, 06531+I_NPN, 06532+I_NPN, 06533+I_NPN,    /* AD */
 06534+I_NPN, 06535+I_NPN, 06536+I_NPN, 06537+I_NPN,
 06601+I_NPN, 06603+I_NPN, 06605+I_NPN,                 /* DF/RF */
 06611+I_NPN, 06612+I_NPN, 06615+I_NPN, 06616+I_NPN,
 06611+I_NPN,              06615+I_NPN, 06616+I_NPN,
 06621+I_NPN, 06622+I_NPN, 06623+I_NPN, 06626+I_NPN,
 06641+I_NPN, 06643+I_NPN, 06645+I_NPN,
 06661+I_NPN, 06662+I_NPN, 06663+I_NPN,                 /* LPT */
 06664+I_NPN, 06665+I_NPN, 06666+I_NPN, 06667+I_NPN,
 06701+I_NPN, 06702+I_NPN, 06703+I_NPN,                 /* MT */
 06704+I_NPN, 06705+I_NPN, 06706+I_NPN, 06707+I_NPN,
 06711+I_NPN, 06712+I_NPN, 06713+I_NPN,
 06714+I_NPN, 06715+I_NPN, 06716+I_NPN, 06717+I_NPN,
 06721+I_NPN, 06722+I_NPN, 06723+I_NPN, 06724+I_NPN, 06725+I_NPN,
 06741+I_NPN, 06742+I_NPN, 06743+I_NPN,                 /* RK */
 06744+I_NPN, 06745+I_NPN, 06746+I_NPN, 06747+I_NPN,
 06751+I_NPN, 06752+I_NPN, 06753+I_NPN,                 /* RX */
 06754+I_NPN, 06755+I_NPN, 06756+I_NPN, 06757+I_NPN,
 06761+I_NPN, 06762+I_NPN, 06764+I_NPN, 06766+I_NPN,    /* DT */
 06771+I_NPN, 06772+I_NPN, 06774+I_NPN,
 06360+I_NPN, 06361+I_NPN, 06362+I_NPN, 06363+I_NPN,    /* TSC */
 06364+I_NPN, 06365+I_NPN, 06366+I_NPN, 06367+I_NPN,
 06550+I_NPN, 06551+I_NPN, 06552+I_NPN, 06553+I_NPN,    /* FPP8 */
 06554+I_NPN, 06555+I_NPN, 06556+I_NPN, 06557+I_NPN,
              06561+I_NPN,              06563+I_NPN,
 06564+I_NPN, 06565+I_NPN,              06567+I_NPN,

 06201+I_FLD, 06202+I_FLD, 06203+I_FLD,
 00000+I_MRF, 01000+I_MRF, 02000+I_MRF, 03000+I_MRF,
 04000+I_MRF, 05000+I_MRF, 06000+I_IOT,
 07000+I_NPN, 07400+I_NPN, 07401+I_NPN, 07431+I_NPN, 07447+I_NPN,
 07120+I_NPN, 07204+I_NPN, 07240+I_NPN, 07604+I_NPN, 07041+I_NPN,
 07002+I_OP1, 07004+I_OP1, 07006+I_OP1,
 07010+I_OP1, 07012+I_OP1, 07014+I_OP1, 07016+I_OP1,
 07410+I_OP2, 07420+I_OP2, 07430+I_OP2,
 07440+I_OP2, 07450+I_OP2, 07460+I_OP2, 07470+I_OP2,
 07500+I_OP2, 07510+I_OP2, 07520+I_OP2, 07530+I_OP2,
 07540+I_OP2, 07550+I_OP2, 07560+I_OP2, 07570+I_OP2,
 07403+I_OP3, 07405+I_OP3, 07407+I_OP3,
 07411+I_OP3, 07413+I_OP3, 07415+I_OP3, 07417+I_OP3,
 07441+I_OP3, 07443+I_OP3, 07445+I_OP3, 07447+I_OP3,
 07451+I_OP3, 07453+I_OP3, 07455+I_OP3, 07457+I_OP3,
 017403+I_OP3, 017405+I_OP3, 0174017+I_OP3,
 017411+I_OP3, 017413+I_OP3, 017415+I_OP3, 017417+I_OP3,
 017441+I_OP3, 017443+I_OP3, 017445+I_OP3, 017447+I_OP3,
 017451+I_OP3, 017453+I_OP3, 017455+I_OP3, 017457+I_OP3,
 07200+I_OP1, 07100+I_OP1, 07040+I_OP1, 07020+I_OP1, 07001+I_OP1,
 07600+I_OP2, 07404+I_OP2, 07402+I_OP2,
 07601+I_OP3, 07501+I_OP3, 07421+I_OP3,
 07000+I_OP1, 07400+I_OP2, 07401+I_OP3, 017401+I_OP3,
 -1
 };

/* Symbol tables for FPP-8 */

#define F_V_FL          18                              /* flag start */
#define F_M_FL          017                             /* flag mask */
#define F_V_NOP12       0                               /* no opnd 12b */
#define F_V_NOP9        1                               /* no opnd 9b */
#define F_V_AD15        2                               /* 15b dir addr */
#define F_V_AD15X       3                               /* 15b dir addr indx */
#define F_V_IMMX        4                               /* 12b immm indx */
#define F_V_X           5                               /* index */
#define F_V_MRI         6                               /* mem ref ind */
#define F_V_MR1D        7                               /* mem ref dir 1 word */
#define F_V_MR2D        8                               /* mem ref dir 2 word */
#define F_V_LEMU        9                               /* LEA/IMUL */
#define F_V_LEMUI       10                              /* LEAI/IMULI */
#define F_V_LTR         11                              /* LTR */
#define F_V_MRD         12                              /* mem ref direct (enc) */
#define F_NOP12         (F_V_NOP12 << F_V_FL)
#define F_NOP9          (F_V_NOP9 << F_V_FL)
#define F_AD15          (F_V_AD15 << F_V_FL)
#define F_AD15X         (F_V_AD15X << F_V_FL)
#define F_IMMX          (F_V_IMMX << F_V_FL)
#define F_X             (F_V_X << F_V_FL)
#define F_MRI           (F_V_MRI << F_V_FL)
#define F_MR1D          (F_V_MR1D << F_V_FL)
#define F_MR2D          (F_V_MR2D << F_V_FL)
#define F_LEMU          (F_V_LEMU << F_V_FL)
#define F_LEMUI         (F_V_LEMUI << F_V_FL)
#define F_LTR           (F_V_LTR << F_V_FL)
#define F_MRD           (F_V_MRD << F_V_FL)

static const uint32 fmasks[] = {
    07777, 07770, 07770, 07600,
    07770, 07770, 07600, 07600,
    07600, 017600, 017600, 07670,
    07777
    };

/* Memory references are encode dir / decode 1D / decode 2D / indirect */

static const char *fopcode[] = {
    "FEXIT",    "FPAUSE",   "FCLA",     "FNEG",
    "FNORM",    "STARTF",   "STARTD",   "JAC",
                "ALN",      "ATX",      "XTA",
    "FNOP",     "STARTE",
    "LDX",      "ADDX",
    "FLDA",     "FLDA",     "FLDA",     "FLDAI",
    "JEQ",      "JGE",      "JLE",      "JA",
    "JNE",      "JLT",      "JGT",      "JAL",
    "SETX",     "SETB",     "JSA",      "JSR",
    "FADD",     "FADD",     "FADD",     "FADDI",
    "JNX",
    "FSUB",     "FSUB",     "FSUB",     "FSUBI",
    "TRAP3",
    "FDIV",     "FDIV",     "FDIV",     "FDIVI",
    "TRAP4",
    "FMUL",     "FMUL",     "FMUL",     "FMULI",
    "LTREQ",    "LTRGE",    "LTRLE",    "LTRA",
    "LTRNE",    "LTRLT",    "LTRGT",    "LTRAL",
    "FADDM",    "FADDM",    "FADDM",    "FADDMI",
    "IMUL",     "LEA",
    "FSTA",     "FSTA",     "FSTA",     "FSTAI",
    "IMULI",    "LEAI",
    "FMULM",    "FMULM",    "FMULM",    "FMULMI",
    NULL
    };

static const int32 fop_val[] = {
    00000+F_NOP12,  00001+F_NOP12,  00002+F_NOP12,  00003+F_NOP12,
    00004+F_NOP12,  00005+F_NOP12,  00006+F_NOP12,  00007+F_NOP12,
                    00010+F_X,      00020+F_X,      00030+F_X,
    00040+F_NOP9,   00050+F_NOP9,
    00100+F_IMMX,   00110+F_IMMX,
    00000+F_MRD,    00200+F_MR1D,   00400+F_MR2D,   00600+F_MRI,
    01000+F_AD15,   01010+F_AD15,   01020+F_AD15,   01030+F_AD15,
    01040+F_AD15,   01050+F_AD15,   01060+F_AD15,   01070+F_AD15,
    01100+F_AD15,   01110+F_AD15,   01120+F_AD15,   01130+F_AD15,
    01000+F_MRD,    01200+F_MR1D,   01400+F_MR2D,   01600+F_MRI,
    02000+F_AD15X,
    02000+F_MRD,    02200+F_MR1D,   02400+F_MR2D,   02600+F_MRI,
    03000+F_AD15,
    03000+F_MRD,    03200+F_MR1D,   03400+F_MR2D,   03600+F_MRI,
    04000+F_AD15,
    04000+F_MRD,    04200+F_MR1D,   04400+F_MR2D,   04600+F_MRI,
    05000+F_LTR,    05010+F_LTR,    05020+F_LTR,    05030+F_LTR,
    05040+F_LTR,    05050+F_LTR,    05060+F_LTR,    05070+F_LTR,
    05000+F_MRD,    05200+F_MR1D,   05400+F_MR2D,   05600+F_MRI,
    016000+F_LEMU,  006000+F_LEMU,
    06000+F_MRD,    06200+F_MR1D,   06400+F_MR2D,   06600+F_MRI,
    017000+F_LEMUI, 007000+F_LEMUI,
    07000+F_MRD,    07200+F_MR1D,   07400+F_MR2D,   07600+F_MRI,
    -1
    };

/* Operate 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 data
        *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)
#define TSSTOASC(x) ((x) + 040)

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

cflag = (uptr == NULL) || (uptr == &cpu_unit);
inst = val[0];
if (sw & SWMASK ('A')) {                                /* ASCII? */
    if (inst > 0377)
        return SCPE_ARG;
    fprintf (of, FMTASC (inst & 0177));
    return SCPE_OK;
    }
if (sw & SWMASK ('C')) {                                /* characters? */
    fprintf (of, "%c", SIXTOASC ((inst >> 6) & 077));
    fprintf (of, "%c", SIXTOASC (inst & 077));
    return SCPE_OK;
    }
if (sw & SWMASK ('T')) {                                /* TSS8 packed? */
    fprintf (of, "%c", TSSTOASC ((inst >> 6) & 077));
    fprintf (of, "%c", TSSTOASC (inst & 077));
    return SCPE_OK;
    }
if ((sw & SWMASK ('F')) &&                              /* FPP8? */
    ((r = fprint_sym_fpp (of, val)) != SCPE_ARG))
    return r;
if (!(sw & SWMASK ('M')))
    return SCPE_ARG;

/* Instruction decode */

opc = (inst >> 9) & 07;                                 /* get major opcode */
if (opc == 07)                                          /* operate? */
    inst = inst | ((emode & 1) << 12);                  /* include EAE mode */
if (opc == 06) {                                        /* IOT? */
    DEVICE *dptr;
    DIB *dibp;
    uint32 dno = (inst >> 3) & 077;
    for (i = 0; (dptr = amb_dev[i]) != NULL; i++) {     /* check amb devices */
        if ((dptr->ctxt == NULL) ||                     /* no DIB or */
            (dptr->flags & DEV_DIS)) continue;          /* disabled? skip */
        dibp = (DIB *) dptr->ctxt;                      /* get DIB */
        if ((dno >= dibp->dev) ||                       /* IOT for this dev? */
            (dno < (dibp->dev + dibp->num))) {
            inst = inst | ((i + 1) << 12);              /* disambiguate */
            break;                                      /* done */
            }
        }
    }
        
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] & 077777) == (inst & masks[j])) {   /* match? */

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

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

        case I_V_FLD:                                   /* field change */
            fprintf (of, "%s %-o", opcode[i], (inst >> 3) & 07);
            break;

        case I_V_MRF:                                   /* mem ref */
            disp = inst & 0177;                         /* displacement */
            fprintf (of, "%s%s", opcode[i], ((inst & 00400)? " I ": " "));
            if (inst & 0200) {                          /* current page? */
                if (cflag)
                    fprintf (of, "%-o", (addr & 07600) | disp);
                else fprintf (of, "C %-o", disp);
                }
            else fprintf (of, "%-o", disp);             /* page zero */
            break;

        case I_V_IOT:                                   /* IOT */
            fprintf (of, "%s %-o", opcode[i], inst & 0777);
            break;

        case I_V_OP1:                                   /* operate group 1 */
            sp = fprint_opr (of, inst & 0361, j, 0);
            if (opcode[i])
                fprintf (of, (sp? " %s": "%s"), opcode[i]);
            break;

        case I_V_OP2:                                   /* operate group 2 */
            if (opcode[i])
                fprintf (of, "%s", opcode[i]); /* skips */
            fprint_opr (of, inst & 0206, j, opcode[i] != NULL);
            break;      

        case I_V_OP3:                                   /* operate group 3 */
            sp = fprint_opr (of, inst & 0320, j, 0);
            if (opcode[i])
                fprintf (of, (sp? " %s": "%s"), opcode[i]);
            break;
            }                                           /* end case */

        return SCPE_OK;
        }                                               /* end if */
    }                                                   /* end for */
return SCPE_ARG;
}

/* 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)
{
uint32 cflag, d, i, j, k;
t_stat r;
char gbuf[CBUFSIZE];

cflag = (uptr == NULL) || (uptr == &cpu_unit);
while (isspace (*cptr)) cptr++;                         /* absorb spaces */
if ((sw & SWMASK ('A')) || ((*cptr == '\'') && cptr++)) { /* ASCII char? */
    if (cptr[0] == 0)                                   /* must have 1 char */
        return SCPE_ARG;
    val[0] = (t_value) cptr[0] | 0200;
    return SCPE_OK;
    }
if ((sw & SWMASK ('C')) || ((*cptr == '"') && cptr++)) { /* sixbit string? */
    if (cptr[0] == 0)                                   /* must have 1 char */
        return SCPE_ARG;
    val[0] = (((t_value) cptr[0] & 077) << 6) |
              ((t_value) cptr[1] & 077);
    return SCPE_OK;
    }
if ((sw & SWMASK ('T')) || ((*cptr == '"') && cptr++)) { /* TSS8 string? */
    if (cptr[0] == 0)                                   /* must have 1 char */
        return SCPE_ARG;
    val[0] = (((t_value) (cptr[0] - 040) & 077) << 6) |
              ((t_value) (cptr[1] - 040) & 077);
    return SCPE_OK;
    }
if ((r = parse_sym_fpp (cptr, val)) != SCPE_ARG)        /* FPP8 inst? */
    return r;

/* Instruction parse */

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] & 07777;                            /* get value */
j = (opc_val[i] >> I_V_FL) & I_M_FL;                    /* get class */

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

    case I_V_IOT:                                       /* IOT */
        if ((cptr = parse_field (cptr, 0777, &d, 0)) == NULL)
            return SCPE_ARG;                            /* get dev+pulse */
        val[0] = val[0] | d;
        break;

    case I_V_FLD:                                       /* field */
        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] >> I_V_FL) & I_M_FL;
                if (k != j)
                    return SCPE_ARG;
                val[0] = val[0] | (opc_val[i] & 07777);
                }
            else {
                d = get_uint (gbuf, 8, 07, &r);
                if (r != SCPE_OK)
                    return SCPE_ARG;
                val[0] = val[0] | (d << 3);
                break;
                }
            }
        break;

    case I_V_MRF:                                       /* mem ref */
        cptr = get_glyph (cptr, gbuf, 0);               /* get next field */
        if (strcmp (gbuf, "I") == 0) {                  /* indirect? */
            val[0] = val[0] | 0400;
            cptr = get_glyph (cptr, gbuf, 0);
            }
        if ((k = (strcmp (gbuf, "C") == 0)) || (strcmp (gbuf, "Z") == 0)) {
            if ((cptr = parse_field (cptr, 0177, &d, 0)) == NULL)
                return SCPE_ARG;
            val[0] = val[0] | d | (k? 0200: 0);
            }
        else {
            d = get_uint (gbuf, 8, 07777, &r);
            if (r != SCPE_OK)
                return SCPE_ARG;
            if (d <= 0177)
                val[0] = val[0] | d;
            else if (cflag && (((addr ^ d) & 07600) == 0))
                val[0] = val[0] | (d & 0177) | 0200;
            else return SCPE_ARG;
            }
        break;

    case I_V_OP1: case I_V_OP2: case I_V_OP3:           /* operates */
    case I_V_NPN: case I_V_IOA:
        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++) ;
            k = opc_val[i] & 07777;
            if ((opcode[i] == NULL) || (((k ^ val[0]) & 07000) != 0))
                return SCPE_ARG;
            val[0] = val[0] | k;
            }
        break;
        }                                               /* end case */

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

/* FPP8 instruction decode */

t_stat fprint_sym_fpp (FILE *of, t_value *val)
{
uint32 wd1, wd2, xr4b, xr3b, ad15;
uint32 i, j;
extern uint32 fpp_bra, fpp_cmd;

wd1 = (uint32) val[0] | ((fpp_cmd & 04000) << 1);
wd2 = (uint32) val[1];
xr4b = (wd1 >> 3) & 017;
xr3b = wd1 & 07;
ad15 = (xr3b << 12) | wd2;

for (i = 0; fop_val[i] >= 0; i++) {                     /* loop thru ops */
    j = (fop_val[i] >> F_V_FL) & F_M_FL;                /* get class */
    if ((fop_val[i] & 017777) == (wd1 & fmasks[j])) {   /* match? */

        switch (j) {                                    /* case on class */
        case F_V_NOP12:
        case F_V_NOP9:
        case F_V_LTR:                                   /* no operands */
            fprintf (of, "%s", fopcode[i]);
            break;

        case F_V_X:                                     /* index */
            fprintf (of, "%s %o", fopcode[i], xr3b);
            break;

        case F_V_IMMX:                                  /* index imm */
            fprintf (of, "%s %-o,%o", fopcode[i], wd2, xr3b);
            return -1;                                  /* extra word */

        case F_V_AD15:                                  /* 15b address */
            fprintf (of, "%s %-o", fopcode[i], ad15);
            return -1;                                  /* extra word */

        case F_V_AD15X:                                 /* 15b addr, indx */
            fprintf (of, "%s %-o", fopcode[i], ad15);
            if (xr4b >= 010)
                fprintf (of, ",%o+", xr4b & 7);
            else fprintf (of, ",%o", xr4b);
            return -1;                                  /* extra word */

        case F_V_MR1D:                                  /* 1 word direct */
            ad15 = (fpp_bra + (3 * (wd1 & 0177))) & ADDRMASK;
            fprintf (of, "%s %-o", fopcode[i], ad15);
            break;

        case F_V_LEMU:
        case F_V_MR2D:                                  /* 2 word direct */
            fprintf (of, "%s %-o", fopcode[i], ad15);
            if (xr4b >= 010)
                fprintf (of, ",%o+", xr4b & 7);
            else if (xr4b != 0)
                fprintf (of, ",%o", xr4b);
            return -1;                                  /* extra word */

        case F_V_LEMUI:
        case F_V_MRI:                                   /* indirect */
            ad15 = (fpp_bra + (3 * xr3b)) & ADDRMASK;
            fprintf (of, "%s %-o", fopcode[i], ad15);
            if (xr4b >= 010)
                fprintf (of, ",%o+", xr4b & 7);
            else if (xr4b != 0)
                fprintf (of, ",%o", xr4b);
            break;

        case F_V_MRD:                                   /* encode only */
            return SCPE_IERR;
            }

        return SCPE_OK;
        }                                               /* end if */
    }                                                   /* end for */
return SCPE_ARG;
}

/* FPP8 instruction parse */

t_stat parse_sym_fpp (char *cptr, t_value *val)
{
uint32 i, j, ad, xr;
int32 broff, nwd;
char gbuf[CBUFSIZE];

cptr = get_glyph (cptr, gbuf, 0);                       /* get opcode */
for (i = 0; (fopcode[i] != NULL) && (strcmp (fopcode[i], gbuf) != 0) ; i++) ;
if (fopcode[i] == NULL) return SCPE_ARG;
val[0] = fop_val[i] & 07777;                            /* get value */
j = (fop_val[i] >> F_V_FL) & F_M_FL;                    /* get class */
xr = 0;
nwd = 0;

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

    case F_V_NOP12:
    case F_V_NOP9:
    case F_V_LTR:                                       /* no operands */
        break;

    case F_V_X:                                         /* 3b XR */
        if ((cptr = parse_field (cptr, 07, &xr, 0)) == NULL)
            return SCPE_ARG;
        val[0] |= xr;
        break;

    case F_V_IMMX:                                      /* 12b, XR */
        if ((cptr = parse_field (cptr, 07777, &ad, ',')) == NULL)
            return SCPE_ARG;
        if ((*cptr == 0) ||
            ((cptr = parse_fpp_xr (cptr, &xr, FALSE)) == NULL))
            return SCPE_ARG;
        val[0] |= xr;
        val[++nwd] = ad;
        break;

    case F_V_AD15:                                      /* 15b addr */
        if ((cptr = parse_field (cptr, 077777, &ad, 0)) == NULL)
            return SCPE_ARG;
        val[0] |= (ad >> 12) & 07;
        val[++nwd] = ad & 07777;
        break;

    case F_V_AD15X:                                     /* 15b addr, idx */
        if ((cptr = parse_field (cptr, 077777, &ad, ',')) == NULL)
            return SCPE_ARG;
        if ((*cptr == 0) ||
            ((cptr = parse_fpp_xr (cptr, &xr, FALSE)) == NULL))
            return SCPE_ARG;
        val[0] |= ((xr << 3) | ((ad >> 12) & 07));
        val[++nwd] = ad & 07777;
        break;

    case F_V_LEMUI:
    case F_V_MRI:                                       /* indirect */
        if ((cptr = parse_field (cptr, 077777, &ad, ',')) == NULL)
            return SCPE_ARG;
        if ((*cptr != 0) &&
            ((cptr = parse_fpp_xr (cptr, &xr, TRUE)) == NULL))
            return SCPE_ARG;
        if ((broff = test_fpp_addr (ad, 07)) < 0)
            return SCPE_ARG;
        val[0] |= ((xr << 3) | broff);
        break;

    case F_V_MRD:                                       /* direct */
        if ((cptr = parse_field (cptr, 077777, &ad, ',')) == NULL)
            return SCPE_ARG;
        if (((broff = test_fpp_addr (ad, 0177)) < 0) ||
            (*cptr != 0)) {
            if ((*cptr != 0) &&
                ((cptr = parse_fpp_xr (cptr, &xr, TRUE)) == NULL))
                return SCPE_ARG;
            val[0] |= (00400 | (xr << 3) | ((ad >> 12) & 07));
            val[++nwd] = ad & 07777;
            }
        else val[0] |= (00200 | broff);
        break;

    case F_V_LEMU:
        if ((cptr = parse_field (cptr, 077777, &ad, ',')) == NULL)
            return SCPE_ARG;
        if ((*cptr != 0) &&
            ((cptr = parse_fpp_xr (cptr, &xr, TRUE)) == NULL))
            return SCPE_ARG;
        val[0] |= ((xr << 3) | ((ad >> 12) & 07));
        val[++nwd] = ad & 07777;
        break;

    case F_V_MR1D:
    case F_V_MR2D:
        return SCPE_IERR;          
        }                                               /* end case */

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

/* Parse field */

char *parse_field (char *cptr, uint32 max, uint32 *val, uint32 c)
{
char gbuf[CBUFSIZE];
t_stat r;

cptr = get_glyph (cptr, gbuf, c);                       /* get field */
*val = get_uint (gbuf, 8, max, &r);
if (r != SCPE_OK)
    return NULL;
return cptr;
}

/* Parse index register */

char *parse_fpp_xr (char *cptr, uint32 *xr, t_bool inc)
{
char gbuf[CBUFSIZE];
uint32 len;
t_stat r;

cptr = get_glyph (cptr, gbuf, 0);                      /* get field */
len = strlen (gbuf);
if (gbuf[len - 1] == '+') {
    if (!inc)
        return NULL;
    gbuf[len - 1] = 0;
    *xr = 010;
    }
else *xr = 0;
*xr += get_uint (gbuf, 8, 7, &r);
if (r != SCPE_OK)
    return NULL;
return cptr;
}

/* Test address in range of base register */

int32 test_fpp_addr (uint32 ad, uint32 max)
{
uint32 off;
extern uint32 fpp_bra;

off = ad - fpp_bra;
if (((off % 3) != 0) ||
    (off > (max * 3)))
    return -1;
return ((int32) off / 3);
}
