I7094/i7094_lp.c - emulators/simh - Rivoreo Source Code Repositories

 /* i7094_lp.c: IBM 716 line printer simulator

    Copyright (c) 2003-2006, 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.

    lpt          716 line printer

    Internally, the 7094 works only with column binary and is limited to
    72 columns of data.  Each row of the printed line is represented by
    72b of data (two 36b words).  A complete print line consists of 12 rows
    (24 36b words).

    The printer can also echo part of what it prints, namely, the digit rows
    plus the 8+3 and 8+4 combinations.  This was intended for verification of
    check printing.  Echoed data is interspersed with output data in the
    following order:

         output  row 9 to row 1
         echo    row "8+4"
         output  row 0
         echo    row "8+3"
         output  row 11
         echo    row 9
         output  row 12
         echo    row 8 to row 1
 */

 #include "i7094_defs.h"

 #define UNIT_V_CONS             (UNIT_V_UF + 0)         /* print to console */
 #define UNIT_CONS               (1u << UNIT_V_CONS)
 #define UNIT_V_BZ               (UNIT_V_UF + 1)
 #define UNIT_V_48               (UNIT_V_UF + 2)
 #define UNIT_BZ                 (1 << UNIT_V_BZ)
 #define UNIT_48                 (1 << UNIT_V_48)
 #define GET_PCHAIN(x)           (((x) >> UNIT_V_BZ) & (UNIT_BZ|UNIT_48))

 #define LPT_BINLNT              24                      /* bin buffer length */
 #define LPT_ECHLNT              22                      /* echo buffer length */
 #define LPT_CHRLNT              80                      /* char buffer length */

 #define LPS_INIT                0                       /* init state */
 #define LPS_DATA                1                       /* print data state */
 #define ECS_DATA                2                       /* echo data state */
 #define LPS_END                 3                       /* end state */

 #define LPB_9ROW                0                       /* bin buf: 9 row */
 #define LPB_8ROW                2                       /*  8 row */
 #define LPB_4ROW                10                      /*  4 row */
 #define LPB_3ROW                12                      /*  3 row */
 #define LPB_1ROW                16                      /*  1 row */
 #define LPB_12ROW               22                      /* 12 row */

 #define ECB_84ROW               0                       /* echo buf: 8-4 row */
 #define ECB_83ROW               2                       /*  8-3 row */
 #define ECB_9ROW                4                       /*  9 row */

 #define ECHO_F                  0100                    /* echo map: flag */
 #define ECHO_MASK               0037                    /* mask */

 #define CMD_BIN                 1                       /* cmd: bcd/bin */
 #define CMD_ECHO                2                       /* cmd: wrs/rds */

 uint32 lpt_sta = 0;                                     /* state */
 uint32 lpt_bptr = 0;                                    /* buffer ptr */
 uint32 lpt_cmd = 0;                                     /* modes */
 uint32 lpt_tstart = 27500;                              /* timing */
 uint32 lpt_tstop = 27500;
 uint32 lpt_tleft = 150;
 uint32 lpt_tright = 4000;
 t_uint64 lpt_chob = 0;
 uint32 lpt_chob_v = 0;
 t_uint64 lpt_bbuf[LPT_BINLNT];                          /* binary buffer */
 t_uint64 lpt_ebuf[LPT_ECHLNT];                          /* echo buffer */


 /* Echo ordering map */

 static const uint8 echo_map[LPT_BINLNT + LPT_ECHLNT] = {
   0,  1,  2,  3,  4,  5,  6,  7,                        /* write 9 to 1 */
   8,  9, 10, 11, 12, 13, 14, 15,
  16, 17,
   0+ECHO_F,  1+ECHO_F,                                  /* echo 8+4 */
  18, 19,                                                /* write 0 */
   2+ECHO_F,  3+ECHO_F,                                  /* echo 8+3 */
  20, 21,                                                /* write 11 */
   4+ECHO_F,  5+ECHO_F,                                  /* echo 9 */
  22, 23,                                                /* write 12 */
   6+ECHO_F,  7+ECHO_F,  8+ECHO_F,  9+ECHO_F,            /* echo 8 to 1 */
  10+ECHO_F, 11+ECHO_F, 12+ECHO_F, 13+ECHO_F,
  14+ECHO_F, 15+ECHO_F, 16+ECHO_F, 17+ECHO_F,
  18+ECHO_F, 19+ECHO_F, 20+ECHO_F, 21+ECHO_F
  };

 extern uint32 ind_ioc;
 extern t_uint64 bit_masks[36];
 extern uint32 col_masks[12];
 extern char bcd_to_ascii_a[64];
 extern char bcd_to_ascii_h[64];
 extern char bcd_to_pca[64];
 extern char bcd_to_pch[64];

 char *pch_table[4] = {
     bcd_to_ascii_h, bcd_to_ascii_a, bcd_to_pch, bcd_to_pca,
     };

 t_stat lpt_reset (DEVICE *dptr);
 t_stat lpt_svc (UNIT *uptr);
 t_stat lpt_chsel (uint32 ch, uint32 sel, uint32 unit);
 t_stat lpt_chwr (uint32 ch, t_uint64 val, uint32 flags);
 t_stat lpt_end_line (UNIT *uptr);

 extern char colbin_to_bcd (uint32 colbin);

 /* LPT data structures

    lpt_dev      LPT device descriptor
    lpt_unit     LPT unit descriptor
    lpt_reg      LPT register list
 */

 DIB lpt_dib = { &lpt_chsel, &lpt_chwr };

 UNIT lpt_unit = {
     UDATA (&lpt_svc, UNIT_SEQ+UNIT_ATTABLE+UNIT_CONS, 0)
     };

 REG lpt_reg[] = {
     { ORDATA (STATE, lpt_sta, 2) },
     { ORDATA (CMD, lpt_cmd, 2) },
     { ORDATA (CHOB, lpt_chob, 36) },
     { FLDATA (CHOBV, lpt_chob_v, 0) },
     { DRDATA (BPTR, lpt_bptr, 6), PV_LEFT },
     { BRDATA (BUF, lpt_bbuf, 8, 36, LPT_BINLNT) },
     { BRDATA (EBUF, lpt_ebuf, 8, 36, LPT_ECHLNT) },
     { DRDATA (POS, lpt_unit.pos, T_ADDR_W), PV_LEFT },
     { DRDATA (TSTART, lpt_tstart, 24), PV_LEFT + REG_NZ },
     { DRDATA (TSTOP, lpt_tstop, 24), PV_LEFT + REG_NZ },
     { DRDATA (TLEFT, lpt_tleft, 24), PV_LEFT + REG_NZ },
     { DRDATA (TRIGHT, lpt_tright, 24), PV_LEFT + REG_NZ },
     { NULL }
     };

 MTAB lpt_mod[] = {
     { UNIT_CONS, UNIT_CONS, "default to console", "DEFAULT" },
     { UNIT_CONS, 0        , "no default device", "NODEFAULT" },
     { UNIT_48, UNIT_48, "48 character chain", "48" },
     { UNIT_48, 0,       "64 character chain", "64" },
     { UNIT_BZ, UNIT_BZ, "business set", "BUSINESS" },
     { UNIT_BZ, 0,       "Fortran set", "FORTRAN" },
     { 0 }
     };

 DEVICE lpt_dev = {
     "LPT", &lpt_unit, lpt_reg, lpt_mod,
     1, 10, 31, 1, 8, 7,
     NULL, NULL, &lpt_reset,
     NULL, NULL, NULL,
     &lpt_dib, DEV_DISABLE
     };

 /* Channel select routine */

 t_stat lpt_chsel (uint32 ch, uint32 sel, uint32 unit)
 {
 if (sel & CHSL_NDS) return ch6_end_nds (ch);            /* nds? nop */

 switch (sel) {                                          /* case on cmd */

     case CHSL_RDS:                                      /* read */
     case CHSL_WRS:                                      /* write */
         if (!(lpt_unit.flags & (UNIT_ATT|UNIT_CONS)))   /* not attached? */
             return SCPE_UNATT;
         if (sim_is_active (&lpt_unit))                  /* busy? */
             return ERR_STALL;
         lpt_cmd = ((unit & 02)? CMD_BIN: 0) |           /* save modes */
             ((sel == CHSL_RDS)? CMD_ECHO: 0);
         lpt_sta = LPS_INIT;                             /* initial state */
         sim_activate (&lpt_unit, lpt_tstart);           /* start reader */
         break;

     default:                                            /* other */
         return STOP_ILLIOP;
         }

 return SCPE_OK;
 }

 /* Channel write routine

    - Normal mode is processed here
    - Echo mode is processed in the service routine (like a read) */

 t_stat lpt_chwr (uint32 ch, t_uint64 val, uint32 eorfl)
 {
 uint32 u = (lpt_cmd & CMD_BIN)? U_LPBIN: U_LPBCD;       /* reconstruct unit */

 lpt_chob = val & DMASK;                                 /* store data */
 lpt_chob_v = 1;                                         /* set valid */
 if (lpt_sta == ECS_DATA) return SCPE_OK;
 if (lpt_sta == LPS_DATA) {
     lpt_bbuf[lpt_bptr++] = lpt_chob;                    /* store data */
     if (eorfl ||                                        /* end record, or */
         ((lpt_cmd & CMD_BIN)?                           /* last word in buffer? */
          (lpt_bptr > (LPB_1ROW + 1)):                   /* (binary mode) */
          (lpt_bptr > (LPB_12ROW + 1)))) {               /* (normal mode) */
         ch6_set_flags (CH_A, u, CHF_EOR);               /* set eor */
         return lpt_end_line (&lpt_unit);
         }
     return SCPE_OK;
     }
 return SCPE_IERR;
 }

 /* Unit timeout */

 t_stat lpt_svc (UNIT *uptr)
 {
 uint32 u = (lpt_cmd & CMD_BIN)? U_LPBIN: U_LPBCD;       /* reconstruct unit */
 uint32 i, map;

 switch (lpt_sta) {                                      /* case on state */

     case LPS_INIT:                                      /* initial state */
         for (i = 0; i < LPT_BINLNT; i++)                /* clear data buffer */
             lpt_bbuf[i] = 0;
         for (i = 0; i < LPT_ECHLNT; i++)                /* clear echo buffer */
             lpt_ebuf[i] = 0;
         if (lpt_cmd & CMD_BIN) lpt_bptr = LPB_1ROW;     /* set buffer ptr */
         else lpt_bptr = LPB_9ROW;
         if (lpt_cmd & CMD_ECHO) lpt_sta = ECS_DATA;     /* set data state */
         else lpt_sta = LPS_DATA;
         ch6_req_wr (CH_A, u);                           /* request channel */
         lpt_chob = 0;                                   /* clr, inval buffer */
         lpt_chob_v = 0;
         sim_activate (uptr, lpt_tleft);                 /* go again */
         break;

     case LPS_DATA:                                      /* print data state */
         if (!ch6_qconn (CH_A, u))                       /* disconnect? */
             return lpt_end_line (uptr);                 /* line is done */
         if (lpt_chob_v) lpt_chob_v = 0;                 /* valid? clear */
         else ind_ioc = 1;                               /* no, io check */
         ch6_req_wr (CH_A, u);                           /* request chan again */
         sim_activate (uptr, (lpt_bptr & 1)? lpt_tleft: lpt_tright);
         break;

     case ECS_DATA:                                      /* echo data state */
         map = echo_map[lpt_bptr++];                     /* map column */
         if (map == ECHO_F) {                            /* first echo? */
             lpt_ebuf[ECB_84ROW] = lpt_bbuf[LPB_8ROW] & lpt_bbuf[LPB_4ROW];
             lpt_ebuf[ECB_84ROW + 1] = lpt_bbuf[LPB_8ROW + 1] & lpt_bbuf[LPB_4ROW + 1];
             lpt_ebuf[ECB_83ROW] = lpt_bbuf[LPB_8ROW] & lpt_bbuf[LPB_3ROW];
             lpt_ebuf[ECB_83ROW + 1] = lpt_bbuf[LPB_8ROW + 1] & lpt_bbuf[LPB_3ROW + 1];
             for (i = 0; i < 18; i++)                    /* copy rows 9.. 1 */
                 lpt_ebuf[ECB_9ROW + i] = lpt_bbuf[LPB_9ROW + i];
             }
         if (map & ECHO_F) {                             /* echo cycle */
             ch6_req_rd (CH_A, u, lpt_ebuf[map & ECHO_MASK], 0);
             if (lpt_bptr >= (LPT_BINLNT + LPT_ECHLNT))
                 return lpt_end_line (uptr);             /* done? */
             sim_activate (uptr, lpt_tleft);             /* short timer */
             }
         else {                                          /* print cycle */
             if (lpt_chob_v) lpt_chob_v = 0;             /* valid? clear */
             else ind_ioc = 1;                           /* no, io check */
             lpt_bbuf[map] = lpt_chob;                   /* store in buffer */
             sim_activate (uptr, (lpt_bptr & 1)? lpt_tleft: lpt_tright);
             }
         if (!(echo_map[lpt_bptr] & ECHO_F))             /* print word next? */
             ch6_req_wr (CH_A, u);                       /* req channel */
         break;

     case LPS_END:                                       /* end state */
         if (ch6_qconn (CH_A, u)) {                      /* lpt still conn? */
             lpt_sta = LPS_INIT;                         /* initial state */
             sim_activate (uptr, 1);                     /* next line */
             }
         break;
         }

 return SCPE_OK;
 }

 /* End line routine */

 t_stat lpt_end_line (UNIT *uptr)
 {
 uint32 i, j, col, row, bufw, colbin;
 char *pch, bcd, lpt_cbuf[LPT_CHRLNT + 1];
 t_uint64 dat;

 pch = pch_table[GET_PCHAIN (lpt_unit.flags)];           /* get print chain */
 for (col = 0; col < (LPT_CHRLNT + 1); col++)            /* clear ascii buf */
     lpt_cbuf[col] = ' ';
 for (col = 0; col < 72; col++) {                        /* proc 72 columns */
     colbin = 0;
     dat = bit_masks[35 - (col % 36)];                   /* mask for column */
     for (row = 0; row < 12; row++) {                    /* proc 12 rows */
         bufw = (row * 2) + (col / 36);                  /* index to buffer */
         if (lpt_bbuf[bufw] & dat) colbin |= col_masks[row];
         }
     bcd = colbin_to_bcd (colbin);                       /* column bin -> BCD */
     lpt_cbuf[col] = pch[bcd];                           /* -> ASCII */
     }
 for (i = LPT_CHRLNT; (i > 0) &&
     (lpt_cbuf[i - 1] == ' '); --i) ;                    /* trim spaces */
 lpt_cbuf[i++] = '\n';                                   /* append nl */
 if (uptr->flags & UNIT_ATT) {                           /* file? */
     fxwrite (lpt_cbuf, 1, i, uptr->fileref);            /* write line */
     if (ferror (uptr->fileref)) {                       /* error? */
         perror ("LPT I/O error");
         clearerr (uptr->fileref);
         return SCPE_IOERR;
         }
     uptr->pos = ftell (uptr->fileref);                  /* update position */
     }
 else if (uptr->flags & UNIT_CONS) {                     /* print to console? */
     for (j = 0; j < i; j++) sim_putchar (lpt_cbuf[j]);
     sim_putchar ('\r');
     }
 else return SCPE_UNATT;                                 /* otherwise error */
 uptr->pos = uptr->pos + strlen (lpt_cbuf);              /* count char */
 lpt_sta = LPS_END;                                      /* end line state */
 sim_cancel (uptr);                                      /* cancel current */
 sim_activate (uptr, lpt_tstop);                         /* long timer */
 return SCPE_OK;
 }

 /* Reset routine */

 t_stat lpt_reset (DEVICE *dptr)
 {
 uint32 i;

 for (i = 0; i < LPT_BINLNT; i++) lpt_bbuf[i] = 0;       /* clear bin buf */
 for (i = 0; i < LPT_ECHLNT; i++) lpt_ebuf[i] = 0;       /* clear echo buf */
 lpt_sta = 0;                                            /* clear state */
 lpt_cmd = 0;                                            /* clear modes */
 lpt_bptr = 0;                                           /* clear buf ptr */
 lpt_chob = 0;
 lpt_chob_v = 0;
 sim_cancel (&lpt_unit);                                 /* stop printer */
 return SCPE_OK;
 }
	/* i7094_lp.c: IBM 716 line printer simulator

	Copyright (c) 2003-2006, 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.

	lpt 716 line printer

	Internally, the 7094 works only with column binary and is limited to
	72 columns of data. Each row of the printed line is represented by
	72b of data (two 36b words). A complete print line consists of 12 rows
	(24 36b words).

	The printer can also echo part of what it prints, namely, the digit rows
	plus the 8+3 and 8+4 combinations. This was intended for verification of
	check printing. Echoed data is interspersed with output data in the
	following order:

	output row 9 to row 1
	echo row "8+4"
	output row 0
	echo row "8+3"
	output row 11
	echo row 9
	output row 12
	echo row 8 to row 1
	*/

	#include "i7094_defs.h"

	#define UNIT_V_CONS (UNIT_V_UF + 0) /* print to console */
	#define UNIT_CONS (1u << UNIT_V_CONS)
	#define UNIT_V_BZ (UNIT_V_UF + 1)
	#define UNIT_V_48 (UNIT_V_UF + 2)
	#define UNIT_BZ (1 << UNIT_V_BZ)
	#define UNIT_48 (1 << UNIT_V_48)
	#define GET_PCHAIN(x) (((x) >> UNIT_V_BZ) & (UNIT_BZ\|UNIT_48))

	#define LPT_BINLNT 24 /* bin buffer length */
	#define LPT_ECHLNT 22 /* echo buffer length */
	#define LPT_CHRLNT 80 /* char buffer length */

	#define LPS_INIT 0 /* init state */
	#define LPS_DATA 1 /* print data state */
	#define ECS_DATA 2 /* echo data state */
	#define LPS_END 3 /* end state */

	#define LPB_9ROW 0 /* bin buf: 9 row */
	#define LPB_8ROW 2 /* 8 row */
	#define LPB_4ROW 10 /* 4 row */
	#define LPB_3ROW 12 /* 3 row */
	#define LPB_1ROW 16 /* 1 row */
	#define LPB_12ROW 22 /* 12 row */

	#define ECB_84ROW 0 /* echo buf: 8-4 row */
	#define ECB_83ROW 2 /* 8-3 row */
	#define ECB_9ROW 4 /* 9 row */

	#define ECHO_F 0100 /* echo map: flag */
	#define ECHO_MASK 0037 /* mask */

	#define CMD_BIN 1 /* cmd: bcd/bin */
	#define CMD_ECHO 2 /* cmd: wrs/rds */

	uint32 lpt_sta = 0; /* state */
	uint32 lpt_bptr = 0; /* buffer ptr */
	uint32 lpt_cmd = 0; /* modes */
	uint32 lpt_tstart = 27500; /* timing */
	uint32 lpt_tstop = 27500;
	uint32 lpt_tleft = 150;
	uint32 lpt_tright = 4000;
	t_uint64 lpt_chob = 0;
	uint32 lpt_chob_v = 0;
	t_uint64 lpt_bbuf[LPT_BINLNT]; /* binary buffer */
	t_uint64 lpt_ebuf[LPT_ECHLNT]; /* echo buffer */


	/* Echo ordering map */

	static const uint8 echo_map[LPT_BINLNT + LPT_ECHLNT] = {
	0, 1, 2, 3, 4, 5, 6, 7, /* write 9 to 1 */
	8, 9, 10, 11, 12, 13, 14, 15,
	16, 17,
	0+ECHO_F, 1+ECHO_F, /* echo 8+4 */
	18, 19, /* write 0 */
	2+ECHO_F, 3+ECHO_F, /* echo 8+3 */
	20, 21, /* write 11 */
	4+ECHO_F, 5+ECHO_F, /* echo 9 */
	22, 23, /* write 12 */
	6+ECHO_F, 7+ECHO_F, 8+ECHO_F, 9+ECHO_F, /* echo 8 to 1 */
	10+ECHO_F, 11+ECHO_F, 12+ECHO_F, 13+ECHO_F,
	14+ECHO_F, 15+ECHO_F, 16+ECHO_F, 17+ECHO_F,
	18+ECHO_F, 19+ECHO_F, 20+ECHO_F, 21+ECHO_F
	};

	extern uint32 ind_ioc;
	extern t_uint64 bit_masks[36];
	extern uint32 col_masks[12];
	extern char bcd_to_ascii_a[64];
	extern char bcd_to_ascii_h[64];
	extern char bcd_to_pca[64];
	extern char bcd_to_pch[64];

	char *pch_table[4] = {
	bcd_to_ascii_h, bcd_to_ascii_a, bcd_to_pch, bcd_to_pca,
	};

	t_stat lpt_reset (DEVICE *dptr);
	t_stat lpt_svc (UNIT *uptr);
	t_stat lpt_chsel (uint32 ch, uint32 sel, uint32 unit);
	t_stat lpt_chwr (uint32 ch, t_uint64 val, uint32 flags);
	t_stat lpt_end_line (UNIT *uptr);

	extern char colbin_to_bcd (uint32 colbin);

	/* LPT data structures

	lpt_dev LPT device descriptor
	lpt_unit LPT unit descriptor
	lpt_reg LPT register list
	*/

	DIB lpt_dib = { &lpt_chsel, &lpt_chwr };

	UNIT lpt_unit = {
	UDATA (&lpt_svc, UNIT_SEQ+UNIT_ATTABLE+UNIT_CONS, 0)
	};

	REG lpt_reg[] = {
	{ ORDATA (STATE, lpt_sta, 2) },
	{ ORDATA (CMD, lpt_cmd, 2) },
	{ ORDATA (CHOB, lpt_chob, 36) },
	{ FLDATA (CHOBV, lpt_chob_v, 0) },
	{ DRDATA (BPTR, lpt_bptr, 6), PV_LEFT },
	{ BRDATA (BUF, lpt_bbuf, 8, 36, LPT_BINLNT) },
	{ BRDATA (EBUF, lpt_ebuf, 8, 36, LPT_ECHLNT) },
	{ DRDATA (POS, lpt_unit.pos, T_ADDR_W), PV_LEFT },
	{ DRDATA (TSTART, lpt_tstart, 24), PV_LEFT + REG_NZ },
	{ DRDATA (TSTOP, lpt_tstop, 24), PV_LEFT + REG_NZ },
	{ DRDATA (TLEFT, lpt_tleft, 24), PV_LEFT + REG_NZ },
	{ DRDATA (TRIGHT, lpt_tright, 24), PV_LEFT + REG_NZ },
	{ NULL }
	};

	MTAB lpt_mod[] = {
	{ UNIT_CONS, UNIT_CONS, "default to console", "DEFAULT" },
	{ UNIT_CONS, 0 , "no default device", "NODEFAULT" },
	{ UNIT_48, UNIT_48, "48 character chain", "48" },
	{ UNIT_48, 0, "64 character chain", "64" },
	{ UNIT_BZ, UNIT_BZ, "business set", "BUSINESS" },
	{ UNIT_BZ, 0, "Fortran set", "FORTRAN" },
	{ 0 }
	};

	DEVICE lpt_dev = {
	"LPT", &lpt_unit, lpt_reg, lpt_mod,
	1, 10, 31, 1, 8, 7,
	NULL, NULL, &lpt_reset,
	NULL, NULL, NULL,
	&lpt_dib, DEV_DISABLE
	};

	/* Channel select routine */

	t_stat lpt_chsel (uint32 ch, uint32 sel, uint32 unit)
	{
	if (sel & CHSL_NDS) return ch6_end_nds (ch); /* nds? nop */

	switch (sel) { /* case on cmd */

	case CHSL_RDS: /* read */
	case CHSL_WRS: /* write */
	if (!(lpt_unit.flags & (UNIT_ATT\|UNIT_CONS))) /* not attached? */
	return SCPE_UNATT;
	if (sim_is_active (&lpt_unit)) /* busy? */
	return ERR_STALL;
	lpt_cmd = ((unit & 02)? CMD_BIN: 0) \| /* save modes */
	((sel == CHSL_RDS)? CMD_ECHO: 0);
	lpt_sta = LPS_INIT; /* initial state */
	sim_activate (&lpt_unit, lpt_tstart); /* start reader */
	break;

	default: /* other */
	return STOP_ILLIOP;
	}

	return SCPE_OK;
	}

	/* Channel write routine

	- Normal mode is processed here
	- Echo mode is processed in the service routine (like a read) */

	t_stat lpt_chwr (uint32 ch, t_uint64 val, uint32 eorfl)
	{
	uint32 u = (lpt_cmd & CMD_BIN)? U_LPBIN: U_LPBCD; /* reconstruct unit */

	lpt_chob = val & DMASK; /* store data */
	lpt_chob_v = 1; /* set valid */
	if (lpt_sta == ECS_DATA) return SCPE_OK;
	if (lpt_sta == LPS_DATA) {
	lpt_bbuf[lpt_bptr++] = lpt_chob; /* store data */
	if (eorfl \|\| /* end record, or */
	((lpt_cmd & CMD_BIN)? /* last word in buffer? */
	(lpt_bptr > (LPB_1ROW + 1)): /* (binary mode) */
	(lpt_bptr > (LPB_12ROW + 1)))) { /* (normal mode) */
	ch6_set_flags (CH_A, u, CHF_EOR); /* set eor */
	return lpt_end_line (&lpt_unit);
	}
	return SCPE_OK;
	}
	return SCPE_IERR;
	}

	/* Unit timeout */

	t_stat lpt_svc (UNIT *uptr)
	{
	uint32 u = (lpt_cmd & CMD_BIN)? U_LPBIN: U_LPBCD; /* reconstruct unit */
	uint32 i, map;

	switch (lpt_sta) { /* case on state */

	case LPS_INIT: /* initial state */
	for (i = 0; i < LPT_BINLNT; i++) /* clear data buffer */
	lpt_bbuf[i] = 0;
	for (i = 0; i < LPT_ECHLNT; i++) /* clear echo buffer */
	lpt_ebuf[i] = 0;
	if (lpt_cmd & CMD_BIN) lpt_bptr = LPB_1ROW; /* set buffer ptr */
	else lpt_bptr = LPB_9ROW;
	if (lpt_cmd & CMD_ECHO) lpt_sta = ECS_DATA; /* set data state */
	else lpt_sta = LPS_DATA;
	ch6_req_wr (CH_A, u); /* request channel */
	lpt_chob = 0; /* clr, inval buffer */
	lpt_chob_v = 0;
	sim_activate (uptr, lpt_tleft); /* go again */
	break;

	case LPS_DATA: /* print data state */
	if (!ch6_qconn (CH_A, u)) /* disconnect? */
	return lpt_end_line (uptr); /* line is done */
	if (lpt_chob_v) lpt_chob_v = 0; /* valid? clear */
	else ind_ioc = 1; /* no, io check */
	ch6_req_wr (CH_A, u); /* request chan again */
	sim_activate (uptr, (lpt_bptr & 1)? lpt_tleft: lpt_tright);
	break;

	case ECS_DATA: /* echo data state */
	map = echo_map[lpt_bptr++]; /* map column */
	if (map == ECHO_F) { /* first echo? */
	lpt_ebuf[ECB_84ROW] = lpt_bbuf[LPB_8ROW] & lpt_bbuf[LPB_4ROW];
	lpt_ebuf[ECB_84ROW + 1] = lpt_bbuf[LPB_8ROW + 1] & lpt_bbuf[LPB_4ROW + 1];
	lpt_ebuf[ECB_83ROW] = lpt_bbuf[LPB_8ROW] & lpt_bbuf[LPB_3ROW];
	lpt_ebuf[ECB_83ROW + 1] = lpt_bbuf[LPB_8ROW + 1] & lpt_bbuf[LPB_3ROW + 1];
	for (i = 0; i < 18; i++) /* copy rows 9.. 1 */
	lpt_ebuf[ECB_9ROW + i] = lpt_bbuf[LPB_9ROW + i];
	}
	if (map & ECHO_F) { /* echo cycle */
	ch6_req_rd (CH_A, u, lpt_ebuf[map & ECHO_MASK], 0);
	if (lpt_bptr >= (LPT_BINLNT + LPT_ECHLNT))
	return lpt_end_line (uptr); /* done? */
	sim_activate (uptr, lpt_tleft); /* short timer */
	}
	else { /* print cycle */
	if (lpt_chob_v) lpt_chob_v = 0; /* valid? clear */
	else ind_ioc = 1; /* no, io check */
	lpt_bbuf[map] = lpt_chob; /* store in buffer */
	sim_activate (uptr, (lpt_bptr & 1)? lpt_tleft: lpt_tright);
	}
	if (!(echo_map[lpt_bptr] & ECHO_F)) /* print word next? */
	ch6_req_wr (CH_A, u); /* req channel */
	break;

	case LPS_END: /* end state */
	if (ch6_qconn (CH_A, u)) { /* lpt still conn? */
	lpt_sta = LPS_INIT; /* initial state */
	sim_activate (uptr, 1); /* next line */
	}
	break;
	}

	return SCPE_OK;
	}

	/* End line routine */

	t_stat lpt_end_line (UNIT *uptr)
	{
	uint32 i, j, col, row, bufw, colbin;
	char *pch, bcd, lpt_cbuf[LPT_CHRLNT + 1];
	t_uint64 dat;

	pch = pch_table[GET_PCHAIN (lpt_unit.flags)]; /* get print chain */
	for (col = 0; col < (LPT_CHRLNT + 1); col++) /* clear ascii buf */
	lpt_cbuf[col] = ' ';
	for (col = 0; col < 72; col++) { /* proc 72 columns */
	colbin = 0;
	dat = bit_masks[35 - (col % 36)]; /* mask for column */
	for (row = 0; row < 12; row++) { /* proc 12 rows */
	bufw = (row * 2) + (col / 36); /* index to buffer */
	if (lpt_bbuf[bufw] & dat) colbin \|= col_masks[row];
	}
	bcd = colbin_to_bcd (colbin); /* column bin -> BCD */
	lpt_cbuf[col] = pch[bcd]; /* -> ASCII */
	}
	for (i = LPT_CHRLNT; (i > 0) &&
	(lpt_cbuf[i - 1] == ' '); --i) ; /* trim spaces */
	lpt_cbuf[i++] = '\n'; /* append nl */
	if (uptr->flags & UNIT_ATT) { /* file? */
	fxwrite (lpt_cbuf, 1, i, uptr->fileref); /* write line */
	if (ferror (uptr->fileref)) { /* error? */
	perror ("LPT I/O error");
	clearerr (uptr->fileref);
	return SCPE_IOERR;
	}
	uptr->pos = ftell (uptr->fileref); /* update position */
	}
	else if (uptr->flags & UNIT_CONS) { /* print to console? */
	for (j = 0; j < i; j++) sim_putchar (lpt_cbuf[j]);
	sim_putchar ('\r');
	}
	else return SCPE_UNATT; /* otherwise error */
	uptr->pos = uptr->pos + strlen (lpt_cbuf); /* count char */
	lpt_sta = LPS_END; /* end line state */
	sim_cancel (uptr); /* cancel current */
	sim_activate (uptr, lpt_tstop); /* long timer */
	return SCPE_OK;
	}

	/* Reset routine */

	t_stat lpt_reset (DEVICE *dptr)
	{
	uint32 i;

	for (i = 0; i < LPT_BINLNT; i++) lpt_bbuf[i] = 0; /* clear bin buf */
	for (i = 0; i < LPT_ECHLNT; i++) lpt_ebuf[i] = 0; /* clear echo buf */
	lpt_sta = 0; /* clear state */
	lpt_cmd = 0; /* clear modes */
	lpt_bptr = 0; /* clear buf ptr */
	lpt_chob = 0;
	lpt_chob_v = 0;
	sim_cancel (&lpt_unit); /* stop printer */
	return SCPE_OK;
	}