/* id_mt.c: Interdata magnetic tape simulator | |
Copyright (c) 2001-2006, 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. | |
mt M46-494 dual density 9-track magtape controller | |
16-Feb-06 RMS Added tape capacity checking | |
18-Mar-05 RMS Added attached test to detach routine | |
07-Dec-04 RMS Added read-only file support | |
25-Apr-03 RMS Revised for extended file support | |
28-Mar-03 RMS Added multiformat support | |
28-Feb-03 RMS Revised for magtape library | |
20-Feb-03 RMS Fixed read to stop selch on error | |
Magnetic tapes are represented as a series of variable 8b records | |
of the form: | |
32b record length in bytes - exact number | |
byte 0 | |
byte 1 | |
: | |
byte n-2 | |
byte n-1 | |
32b record length in bytes - exact number | |
If the byte count is odd, the record is padded with an extra byte | |
of junk. File marks are represented by a single record length of 0. | |
End of tape is two consecutive end of file marks. | |
*/ | |
#include "id_defs.h" | |
#include "sim_tape.h" | |
#define UST u3 /* unit status */ | |
#define UCMD u4 /* unit command */ | |
#define MT_MAXFR (1 << 16) /* max transfer */ | |
/* Command - in UCMD */ | |
#define MTC_SPCR 0x11 /* backspace */ | |
#define MTC_SKFR 0x13 /* space file rev */ | |
#define MTC_CLR 0x20 /* clear */ | |
#define MTC_RD 0x21 /* read */ | |
#define MTC_WR 0x22 /* write */ | |
#define MTC_SKFF 0x23 /* space file fwd */ | |
#define MTC_WEOF 0x30 /* write eof */ | |
#define MTC_REW 0x38 /* rewind */ | |
#define MTC_MASK 0x3F | |
#define MTC_STOP1 0x40 /* stop, set EOM */ | |
#define MTC_STOP2 0x80 /* stop, set NMTN */ | |
/* Status byte, * = in UST */ | |
#define STA_ERR 0x80 /* error */ | |
#define STA_EOF 0x40 /* end of file */ | |
#define STA_EOT 0x20 /* *end of tape */ | |
#define STA_NMTN 0x10 /* *no motion */ | |
#define STA_UFLGS (STA_EOT|STA_NMTN) /* unit flags */ | |
#define STA_MASK (STA_ERR|STA_EOF|STA_BSY|STA_EOM) | |
#define SET_EX (STA_ERR|STA_EOF|STA_NMTN) | |
extern uint32 int_req[INTSZ], int_enb[INTSZ]; | |
uint8 mtxb[MT_MAXFR]; /* xfer buffer */ | |
uint32 mt_bptr = 0; /* pointer */ | |
uint32 mt_blnt = 0; /* length */ | |
uint32 mt_sta = 0; /* status byte */ | |
uint32 mt_db = 0; /* data buffer */ | |
uint32 mt_xfr = 0; /* data xfr in prog */ | |
uint32 mt_arm[MT_NUMDR] = { 0 }; /* intr armed */ | |
int32 mt_wtime = 10; /* byte latency */ | |
int32 mt_rtime = 1000; /* record latency */ | |
int32 mt_stopioe = 1; /* stop on error */ | |
uint8 mt_tplte[] = { 0, o_MT0, o_MT0*2, o_MT0*3, TPL_END }; | |
static const uint8 bad_cmd[64] = { | |
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | |
0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1 | |
}; | |
DEVICE mt_dev; | |
uint32 mt (uint32 dev, uint32 op, uint32 dat); | |
t_stat mt_svc (UNIT *uptr); | |
t_stat mt_reset (DEVICE *dptr); | |
t_stat mt_attach (UNIT *uptr, char *cptr); | |
t_stat mt_detach (UNIT *uptr); | |
t_stat mt_boot (int32 unitno, DEVICE *dptr); | |
t_stat mt_map_err (UNIT *uptr, t_stat st); | |
/* MT data structures | |
mt_dev MT device descriptor | |
mt_unit MT unit list | |
mt_reg MT register list | |
mt_mod MT modifier list | |
*/ | |
DIB mt_dib = { d_MT, 0, v_MT, mt_tplte, &mt, NULL }; | |
UNIT mt_unit[] = { | |
{ UDATA (&mt_svc, UNIT_ATTABLE + UNIT_ROABLE + UNIT_DISABLE, 0) }, | |
{ UDATA (&mt_svc, UNIT_ATTABLE + UNIT_ROABLE + UNIT_DISABLE, 0) }, | |
{ UDATA (&mt_svc, UNIT_ATTABLE + UNIT_ROABLE + UNIT_DISABLE, 0) }, | |
{ UDATA (&mt_svc, UNIT_ATTABLE + UNIT_ROABLE + UNIT_DISABLE, 0) } | |
}; | |
REG mt_reg[] = { | |
{ HRDATA (STA, mt_sta, 8) }, | |
{ HRDATA (BUF, mt_db, 8) }, | |
{ BRDATA (DBUF, mtxb, 16, 8, MT_MAXFR) }, | |
{ HRDATA (DBPTR, mt_bptr, 16) }, | |
{ HRDATA (DBLNT, mt_blnt, 17), REG_RO }, | |
{ FLDATA (XFR, mt_xfr, 0) }, | |
{ GRDATA (IREQ, int_req[l_MT], 16, MT_NUMDR, i_MT) }, | |
{ GRDATA (IENB, int_enb[l_MT], 16, MT_NUMDR, i_MT) }, | |
{ BRDATA (IARM, mt_arm, 16, 1, MT_NUMDR) }, | |
{ FLDATA (STOP_IOE, mt_stopioe, 0) }, | |
{ DRDATA (WTIME, mt_wtime, 24), PV_LEFT + REG_NZ }, | |
{ DRDATA (RTIME, mt_rtime, 24), PV_LEFT + REG_NZ }, | |
{ URDATA (UST, mt_unit[0].UST, 16, 8, 0, MT_NUMDR, 0) }, | |
{ URDATA (CMD, mt_unit[0].UCMD, 16, 8, 0, MT_NUMDR, 0) }, | |
{ URDATA (POS, mt_unit[0].pos, 10, T_ADDR_W, 0, | |
MT_NUMDR, PV_LEFT | REG_RO) }, | |
{ HRDATA (DEVNO, mt_dib.dno, 8), REG_HRO }, | |
{ HRDATA (SELCH, mt_dib.sch, 1), REG_HRO }, | |
{ NULL } | |
}; | |
MTAB mt_mod[] = { | |
{ MTUF_WLK, 0, "write enabled", "WRITEENABLED", NULL }, | |
{ MTUF_WLK, MTUF_WLK, "write locked", "LOCKED", NULL }, | |
{ MTAB_XTD|MTAB_VUN, 0, "FORMAT", "FORMAT", | |
&sim_tape_set_fmt, &sim_tape_show_fmt, NULL }, | |
{ MTAB_XTD|MTAB_VUN, 0, "CAPACITY", "CAPACITY", | |
&sim_tape_set_capac, &sim_tape_show_capac, NULL }, | |
{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", | |
&set_dev, &show_dev, NULL }, | |
{ MTAB_XTD|MTAB_VDV, 0, "SELCH", "SELCH", | |
&set_sch, &show_sch, NULL }, | |
{ 0 } | |
}; | |
DEVICE mt_dev = { | |
"MT", mt_unit, mt_reg, mt_mod, | |
MT_NUMDR, 10, 31, 1, 16, 8, | |
NULL, NULL, &mt_reset, | |
&mt_boot, &mt_attach, &mt_detach, | |
&mt_dib, DEV_DISABLE | |
}; | |
/* Magtape: IO routine */ | |
uint32 mt (uint32 dev, uint32 op, uint32 dat) | |
{ | |
uint32 i, f, t; | |
uint32 u = (dev - mt_dib.dno) / o_MT0; | |
UNIT *uptr = mt_dev.units + u; | |
switch (op) { /* case IO op */ | |
case IO_ADR: /* select */ | |
sch_adr (mt_dib.sch, dev); /* inform sel ch */ | |
return BY; /* byte only */ | |
case IO_RD: /* read data */ | |
if (mt_xfr) mt_sta = mt_sta | STA_BSY; /* xfr? set busy */ | |
return mt_db; /* return data */ | |
case IO_WD: /* write data */ | |
if (mt_xfr) { /* transfer? */ | |
mt_sta = mt_sta | STA_BSY; /* set busy */ | |
if ((uptr->UCMD & (MTC_STOP1 | MTC_STOP2)) && | |
((uptr->UCMD & MTC_MASK) == MTC_WR)) /* while stopping? */ | |
mt_sta = mt_sta | STA_ERR; /* write overrun */ | |
} | |
mt_db = dat & DMASK8; /* store data */ | |
break; | |
case IO_SS: /* status */ | |
mt_sta = mt_sta & STA_MASK; /* ctrl status */ | |
if (uptr->flags & UNIT_ATT) /* attached? */ | |
t = mt_sta | (uptr->UST & STA_UFLGS); /* yes, unit status */ | |
else t = mt_sta | STA_DU; /* no, dev unavail */ | |
if (t & SET_EX) t = t | STA_EX; /* test for ex */ | |
return t; | |
case IO_OC: /* command */ | |
mt_arm[u] = int_chg (v_MT + u, dat, mt_arm[u]); | |
f = dat & MTC_MASK; /* get cmd */ | |
if (f == MTC_CLR) { /* clear? */ | |
mt_reset (&mt_dev); /* reset world */ | |
break; | |
} | |
if (((uptr->flags & UNIT_ATT) == 0) || /* ignore if unatt */ | |
bad_cmd[f] || /* or bad cmd */ | |
(((f == MTC_WR) || (f == MTC_WEOF)) && /* or write */ | |
sim_tape_wrp (uptr))) break; /* and protected */ | |
for (i = 0; i < MT_NUMDR; i++) { /* check other drvs */ | |
if (sim_is_active (&mt_unit[i]) && /* active? */ | |
(mt_unit[i].UCMD != MTC_REW)) { /* not rewind? */ | |
sim_cancel (&mt_unit[i]); /* stop */ | |
mt_unit[i].UCMD = 0; | |
} | |
} | |
if (sim_is_active (uptr) && /* unit active? */ | |
!(uptr->UCMD & (MTC_STOP1 | MTC_STOP2))) /* not stopping? */ | |
break; /* ignore */ | |
if ((f == MTC_WR) || (f == MTC_REW)) mt_sta = 0;/* write, rew: bsy=0 */ | |
else mt_sta = STA_BSY; /* bsy=1,nmtn,eom,err=0 */ | |
mt_bptr = mt_blnt = 0; /* not yet started */ | |
if ((f == MTC_RD) || (f == MTC_WR)) /* data xfr? */ | |
mt_xfr = 1; /* set xfr flag */ | |
else mt_xfr = 0; | |
uptr->UCMD = f; /* save cmd */ | |
uptr->UST = 0; /* clr tape stat */ | |
sim_activate (uptr, mt_rtime); /* start op */ | |
break; | |
} | |
return 0; | |
} | |
/* Unit service | |
A given operation can generate up to three interrupts | |
- EOF generates an interrupt when set (read, space, wreof) | |
BUSY will still be set, EOM and NMTN will be clear | |
- After operation complete + delay, EOM generates an interrupt | |
BUSY will be clear, EOM will be set, NMTN will be clear | |
- After a further delay, NMTN generates an interrupt | |
BUSY will be clear, EOM and NMTN will be set | |
Rewind generates an interrupt when NMTN sets | |
*/ | |
t_stat mt_svc (UNIT *uptr) | |
{ | |
uint32 i; | |
int32 u = uptr - mt_dev.units; | |
uint32 dev = mt_dib.dno + (u * o_MT0); | |
t_mtrlnt tbc; | |
t_bool passed_eot; | |
t_stat st, r = SCPE_OK; | |
if ((uptr->flags & UNIT_ATT) == 0) { /* not attached? */ | |
uptr->UCMD = 0; /* clr cmd */ | |
uptr->UST = 0; /* set status */ | |
mt_xfr = 0; /* clr op flags */ | |
mt_sta = STA_ERR | STA_EOM; /* set status */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* interrupt */ | |
return IORETURN (mt_stopioe, SCPE_UNATT); | |
} | |
if (uptr->UCMD & MTC_STOP2) { /* stop, gen NMTN? */ | |
uptr->UCMD = 0; /* clr cmd */ | |
uptr->UST = uptr->UST | STA_NMTN; /* set nmtn */ | |
mt_xfr = 0; /* clr xfr */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* set intr */ | |
return SCPE_OK; | |
} | |
if (uptr->UCMD & MTC_STOP1) { /* stop, gen EOM? */ | |
uptr->UCMD = uptr->UCMD | MTC_STOP2; /* clr cmd */ | |
mt_sta = (mt_sta & ~STA_BSY) | STA_EOM; /* clr busy, set eom */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* set intr */ | |
sim_activate (uptr, mt_rtime); /* schedule */ | |
return SCPE_OK; | |
} | |
passed_eot = sim_tape_eot (uptr); /* passed EOT? */ | |
switch (uptr->UCMD) { /* case on function */ | |
case MTC_REW: /* rewind */ | |
sim_tape_rewind (uptr); /* reposition */ | |
uptr->UCMD = 0; /* clr cmd */ | |
uptr->UST = STA_NMTN | STA_EOT; /* update status */ | |
mt_sta = mt_sta & ~STA_BSY; /* don't set EOM */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* interrupt */ | |
return SCPE_OK; | |
/* For read, busy = 1 => buffer empty | |
For write, busy = 1 => buffer full | |
For read, data transfers continue for the full length of the | |
record, or the maximum size of the transfer buffer | |
For write, data transfers continue until a write is attempted | |
and the buffer is empty | |
*/ | |
case MTC_RD: /* read */ | |
if (mt_blnt == 0) { /* first time? */ | |
st = sim_tape_rdrecf (uptr, mtxb, &tbc, MT_MAXFR); /* read rec */ | |
if (st == MTSE_RECE) mt_sta = mt_sta | STA_ERR; /* rec in err? */ | |
else if (st != SCPE_OK) { /* other error? */ | |
r = mt_map_err (uptr, st); /* map error */ | |
if (sch_actv (mt_dib.sch, dev)) /* if sch, stop */ | |
sch_stop (mt_dib.sch); | |
break; | |
} | |
mt_blnt = tbc; /* set buf lnt */ | |
} | |
if (sch_actv (mt_dib.sch, dev)) { /* sch active? */ | |
i = sch_wrmem (mt_dib.sch, mtxb, mt_blnt); /* store rec in mem */ | |
if (sch_actv (mt_dib.sch, dev)) /* sch still active? */ | |
sch_stop (mt_dib.sch); /* stop chan, long rd */ | |
else if (i < mt_blnt) /* process entire rec? */ | |
mt_sta = mt_sta | STA_ERR; /* no, overrun error */ | |
} | |
else if (mt_bptr < mt_blnt) { /* no, if !eor */ | |
if (!(mt_sta & STA_BSY)) /* busy still clr? */ | |
mt_sta = mt_sta | STA_ERR; /* read overrun */ | |
mt_db = mtxb[mt_bptr++]; /* get next byte */ | |
mt_sta = mt_sta & ~STA_BSY; /* !busy = buf full */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* set intr */ | |
sim_activate (uptr, mt_wtime); /* reschedule */ | |
return SCPE_OK; | |
} | |
break; /* record done */ | |
case MTC_WR: /* write */ | |
if (sch_actv (mt_dib.sch, dev)) { /* sch active? */ | |
mt_bptr = sch_rdmem (mt_dib.sch, mtxb, MT_MAXFR); /* get rec */ | |
if (sch_actv (mt_dib.sch, dev)) /* not done? */ | |
sch_stop (mt_dib.sch); /* stop chan */ | |
} | |
else if (mt_sta & STA_BSY) { /* no, if !eor */ | |
if (mt_bptr < MT_MAXFR) /* if room */ | |
mtxb[mt_bptr++] = mt_db; /* store in buf */ | |
mt_sta = mt_sta & ~STA_BSY; /* !busy = buf emp */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* set intr */ | |
sim_activate (uptr, mt_wtime); /* reschedule */ | |
return SCPE_OK; | |
} | |
if (mt_bptr) { /* any chars? */ | |
if (st = sim_tape_wrrecf (uptr, mtxb, mt_bptr)) /* write, err? */ | |
r = mt_map_err (uptr, st); /* map error */ | |
} | |
break; /* record done */ | |
case MTC_WEOF: /* write eof */ | |
if (st = sim_tape_wrtmk (uptr)) /* write tmk, err? */ | |
r = mt_map_err (uptr, st); /* map error */ | |
mt_sta = mt_sta | STA_EOF; /* set eof */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* interrupt */ | |
break; | |
case MTC_SKFF: /* skip file fwd */ | |
while ((st = sim_tape_sprecf (uptr, &tbc)) == MTSE_OK) ; | |
if (st == MTSE_TMK) { /* stopped by tmk? */ | |
mt_sta = mt_sta | STA_EOF; /* set eof */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* set intr */ | |
} | |
else r = mt_map_err (uptr, st); /* map error */ | |
break; | |
case MTC_SKFR: /* skip file rev */ | |
while ((st = sim_tape_sprecr (uptr, &tbc)) == MTSE_OK) ; | |
if (st == MTSE_TMK) { /* stopped by tmk? */ | |
mt_sta = mt_sta | STA_EOF; /* set eof */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* set intr */ | |
} | |
else r = mt_map_err (uptr, st); /* map error */ | |
break; | |
case MTC_SPCR: /* backspace */ | |
if (st = sim_tape_sprecr (uptr, &tbc)) /* skip rec rev, err? */ | |
r = mt_map_err (uptr, st); /* map error */ | |
break; | |
} /* end case */ | |
if (!passed_eot && sim_tape_eot (uptr)) /* just passed EOT? */ | |
uptr->UST = uptr->UST | STA_EOT; | |
uptr->UCMD = uptr->UCMD | MTC_STOP1; /* set stop stage 1 */ | |
sim_activate (uptr, mt_rtime); /* schedule */ | |
return r; | |
} | |
/* Map tape error status */ | |
t_stat mt_map_err (UNIT *uptr, t_stat st) | |
{ | |
int32 u = uptr - mt_dev.units; | |
switch (st) { | |
case MTSE_FMT: /* illegal fmt */ | |
case MTSE_UNATT: /* not attached */ | |
mt_sta = mt_sta | STA_ERR; | |
case MTSE_OK: /* no error */ | |
return SCPE_IERR; | |
case MTSE_TMK: /* end of file */ | |
mt_sta = mt_sta | STA_EOF; /* set eof */ | |
if (mt_arm[u]) SET_INT (v_MT + u); /* set intr */ | |
break; | |
case MTSE_IOERR: /* IO error */ | |
mt_sta = mt_sta | STA_ERR; /* set err */ | |
if (mt_stopioe) return SCPE_IOERR; | |
break; | |
case MTSE_INVRL: /* invalid rec lnt */ | |
mt_sta = mt_sta | STA_ERR; | |
return SCPE_MTRLNT; | |
case MTSE_WRP: /* write protect */ | |
case MTSE_RECE: /* record in error */ | |
case MTSE_EOM: /* end of medium */ | |
mt_sta = mt_sta | STA_ERR; /* set err */ | |
break; | |
case MTSE_BOT: /* reverse into BOT */ | |
uptr->UST = uptr->UST | STA_EOT; /* set err */ | |
break; | |
} /* end switch */ | |
return SCPE_OK; | |
} | |
/* Reset routine */ | |
t_stat mt_reset (DEVICE *dptr) | |
{ | |
uint32 u; | |
UNIT *uptr; | |
mt_bptr = mt_blnt = 0; /* clr buf */ | |
mt_sta = STA_BSY; /* clr flags */ | |
mt_xfr = 0; /* clr controls */ | |
for (u = 0; u < MT_NUMDR; u++) { /* loop thru units */ | |
CLR_INT (v_MT + u); /* clear int */ | |
CLR_ENB (v_MT + u); /* disable int */ | |
mt_arm[u] = 0; /* disarm int */ | |
uptr = mt_dev.units + u; | |
sim_tape_reset (uptr); /* clear pos flag */ | |
sim_cancel (uptr); /* cancel activity */ | |
uptr->UST = (uptr->UST & STA_UFLGS) | STA_NMTN; /* init status */ | |
uptr->UCMD = 0; /* init cmd */ | |
} | |
return SCPE_OK; | |
} | |
/* Attach routine */ | |
t_stat mt_attach (UNIT *uptr, char *cptr) | |
{ | |
int32 u = uptr - mt_dev.units; | |
t_stat r; | |
r = sim_tape_attach (uptr, cptr); | |
if (r != SCPE_OK) return r; | |
uptr->UST = STA_EOT; | |
if (mt_arm[u]) SET_INT (v_MT + u); | |
return r; | |
} | |
/* Detach routine */ | |
t_stat mt_detach (UNIT* uptr) | |
{ | |
int32 u = uptr - mt_dev.units; | |
t_stat r; | |
if (!(uptr->flags & UNIT_ATT)) return SCPE_OK; | |
r = sim_tape_detach (uptr); | |
if (r != SCPE_OK) return r; | |
if (mt_arm[u]) SET_INT (v_MT + u); | |
uptr->UST = 0; | |
return SCPE_OK; | |
} | |
/* Bootstrap routine */ | |
#define BOOT_START 0x50 | |
#define BOOT_LEN (sizeof (boot_rom) / sizeof (uint8)) | |
static uint8 boot_rom[] = { | |
0xD5, 0x00, 0x00, 0xCF, /* ST: AL CF */ | |
0x43, 0x00, 0x00, 0x80 /* BR 80 */ | |
}; | |
t_stat mt_boot (int32 unitno, DEVICE *dptr) | |
{ | |
extern uint32 PC, dec_flgs; | |
extern uint16 decrom[]; | |
extern DIB sch_dib; | |
uint32 sch_dev; | |
if (decrom[0xD5] & dec_flgs) return SCPE_NOFNC; /* AL defined? */ | |
sim_tape_rewind (&mt_unit[unitno]); /* rewind */ | |
sch_dev = sch_dib.dno + mt_dib.sch; /* sch dev # */ | |
IOWriteBlk (BOOT_START, BOOT_LEN, boot_rom); /* copy boot */ | |
IOWriteB (AL_DEV, mt_dib.dno + (unitno * o_MT0)); /* set dev no for unit */ | |
IOWriteB (AL_IOC, 0xA1); /* set dev cmd */ | |
IOWriteB (AL_SCH, sch_dev); /* set dev no for chan */ | |
PC = BOOT_START; | |
return SCPE_OK; | |
} |