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/* pdp8_tsc.c: PDP-8 ETOS timesharing option board (TSC8-75)
Copyright (c) 2003-2011, 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.
This module is based on Bernhard Baehr's PDP-8/E simulator
PDP-8/E Simulator Source Code
Copyright ) 2001-2003 Bernhard Baehr
TSC8iots.c - IOTs for the TSC8-75 Board plugin
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
tsc TSC8-75 option board
*/
#include "pdp8_defs.h"
extern int32 int_req;
extern int32 SF;
extern int32 tsc_ir; /* "ERIOT" */
extern int32 tsc_pc; /* "ERTB" */
extern int32 tsc_cdf; /* "ECDF" */
extern int32 tsc_enb; /* enable */
#define UNIT_V_SN699 (UNIT_V_UF + 0) /* SN 699 or above */
#define UNIT_SN699 (1 << UNIT_V_SN699)
int32 tsc (int32 IR, int32 AC);
t_stat tsc_reset (DEVICE *dptr);
/* TSC data structures
tsc_dev TSC device descriptor
tsc_unit TSC unit descriptor
tsc_reg TSC register list
*/
DIB tsc_dib = { DEV_TSC, 1, { &tsc } };
UNIT tsc_unit = { UDATA (NULL, UNIT_SN699, 0) };
REG tsc_reg[] = {
{ ORDATAD (IR, tsc_ir, 12, "most recently trapped instruction") },
{ ORDATAD (PC, tsc_pc, 12, "PC of most recently trapped instruction") },
{ FLDATAD (CDF, tsc_cdf, 0, "1 if trapped instruction is CDF, 0 otherwise") },
{ FLDATAD (ENB, tsc_enb, 0, "interrupt enable flag") },
{ FLDATAD (INT, int_req, INT_V_TSC, "interrupt pending flag") },
{ NULL }
};
MTAB tsc_mod[] = {
{ UNIT_SN699, UNIT_SN699, "ESME", "ESME", NULL },
{ UNIT_SN699, 0, "no ESME", "NOESME", NULL },
{ 0 }
};
DEVICE tsc_dev = {
"TSC", &tsc_unit, tsc_reg, tsc_mod,
1, 10, 31, 1, 8, 8,
NULL, NULL, &tsc_reset,
NULL, NULL, NULL,
&tsc_dib, DEV_DISABLE | DEV_DIS
};
/* IOT routine */
int32 tsc (int32 IR, int32 AC)
{
switch (IR & 07) { /* decode IR<9:11> */
case 0: /* ETDS */
tsc_enb = 0; /* disable int req */
int_req = int_req & ~INT_TSC; /* clear flag */
break;
case 1: /* ESKP */
return (int_req & INT_TSC)? IOT_SKP + AC: AC; /* skip on int req */
case 2: /* ECTF */
int_req = int_req & ~INT_TSC; /* clear int req */
break;
case 3: /* ECDF */
AC = AC | ((tsc_ir >> 3) & 07); /* read "ERIOT"<6:8> */
if (tsc_cdf) /* if cdf, skip */
AC = AC | IOT_SKP;
tsc_cdf = 0;
break;
case 4: /* ERTB */
return tsc_pc;
case 5: /* ESME */
if (tsc_unit.flags & UNIT_SN699) { /* enabled? */
if (tsc_cdf && ((tsc_ir & 070) >> 3) == (SF & 07)) {
AC = AC | IOT_SKP;
tsc_cdf = 0;
}
}
break;
case 6: /* ERIOT */
return tsc_ir;
case 7: /* ETEN */
tsc_enb = 1;
break;
} /* end switch */
return AC;
}
/* Reset routine */
t_stat tsc_reset (DEVICE *dptr)
{
tsc_ir = 0;
tsc_pc = 0;
tsc_cdf = 0;
tsc_enb = 0;
int_req = int_req & ~INT_TSC;
return SCPE_OK;
}