/* pdp18b_dt.c: 18b DECtape simulator | |
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. | |
dt (PDP-4, PDP-7) Type 550/555 DECtape | |
(PDP-9) TC02/TU55 DECtape | |
(PDP-15) TC15/TU56 DECtape | |
23-Jun-06 RMS Fixed switch conflict in ATTACH | |
Revised Type 550 header based on DECTOG formatter | |
13-Jun-06 RMS Fixed checksum calculation bug in Type 550 | |
16-Aug-05 RMS Fixed C++ declaration and cast problems | |
25-Jan-04 RMS Revised for device debug support | |
14-Jan-04 RMS Revised IO device call interface | |
Changed sim_fsize calling sequence, added STOP_OFFR | |
26-Oct-03 RMS Cleaned up buffer copy code | |
18-Oct-03 RMS Fixed reverse checksum in read all | |
Added DECtape off reel message | |
Simplified timing | |
25-Apr-03 RMS Revised for extended file support | |
14-Mar-03 RMS Fixed variable size interaction with save/restore | |
17-Oct-02 RMS Fixed bug in end of reel logic | |
05-Oct-02 RMS Added DIB, device number support | |
12-Sep-02 RMS Added 16b format support | |
13-Aug-02 RMS Corrected Type 550 unit select logic | |
25-Jul-02 RMS Added PDP-4 support | |
30-May-02 RMS Widened POS to 32b | |
10-Feb-02 RMS Added PDP-7 support | |
06-Jan-02 RMS Revised enable/disable support | |
29-Nov-01 RMS Added read only unit support | |
25-Nov-01 RMS Revised interrupt structure | |
Changed POS, STATT, LASTT, FLG to arrays | |
29-Aug-01 RMS Added casts to PDP-8 unpack routine | |
17-Jul-01 RMS Moved function prototype | |
11-May-01 RMS Fixed bug in reset | |
26-Apr-01 RMS Added device enable/disable support | |
15-Mar-01 RMS Added 129th word to PDP-8 format | |
18b DECtapes are represented in memory by fixed length buffer of 32b words. | |
Three file formats are supported: | |
18b/36b 256 words per block [256 x 18b] | |
16b 256 words per block [256 x 16b] | |
12b 129 words per block [129 x 12b] | |
When a 16b or 12b DECtape file is read in, it is converted to 18b/36b format. | |
DECtape motion is measured in 3b lines. Time between lines is 33.33us. | |
Tape density is nominally 300 lines per inch. The format of a DECtape (as | |
taken from the PDP-7 formatter) is: | |
reverse end zone 7144 reverse end zone codes ~ 12 feet | |
reverse buffer 200 interblock codes | |
block 0 | |
: | |
block n | |
forward buffer 200 interblock codes | |
forward end zone 7144 forward end zone codes ~ 12 feet | |
A block consists of five 18b header words, a tape-specific number of data | |
words, and five 18b trailer words. All systems except the PDP-8 use a | |
standard block length of 256 words; the PDP-8 uses a standard block length | |
of 86 words (x 18b = 129 words x 12b). PDP-4/7 DECtapes came in two | |
formats. The first 5 controllers used a 4 word header/trailer (missing | |
word 0/4). All later serial numbers used the standard header. The later, | |
standard header/trailer is simulated here. | |
Because a DECtape file only contains data, the simulator cannot support | |
write timing and mark track and can only do a limited implementation | |
of read all and write all. Read all assumes that the tape has been | |
conventionally written forward: | |
header word 0 0 | |
header word 1 block number (for forward reads) | |
header words 2,3 0 | |
header word 4 checksum (for reverse reads) | |
: | |
trailer word 4 checksum (for forward reads) | |
trailer words 3,2 0 | |
trailer word 1 block number (for reverse reads) | |
trailer word 0 0 | |
Write all writes only the data words and dumps the interblock words in the | |
bit bucket. | |
The Type 550 controller has a 4b unit select field, for units 1-8; the TC02 | |
has a 3b unit select field, with unit 8 being represented as 0. The code | |
assumes that the GETUNIT macro returns a unit number in the range of 0-7, | |
with 8 represented as 0, and an invalid unit as -1. | |
*/ | |
#include "pdp18b_defs.h" | |
#define DT_NUMDR 8 /* #drives */ | |
#define UNIT_V_WLK (UNIT_V_UF + 0) /* write locked */ | |
#define UNIT_V_8FMT (UNIT_V_UF + 1) /* 12b format */ | |
#define UNIT_V_11FMT (UNIT_V_UF + 2) /* 16b format */ | |
#define UNIT_WLK (1 << UNIT_V_WLK) | |
#define UNIT_8FMT (1 << UNIT_V_8FMT) | |
#define UNIT_11FMT (1 << UNIT_V_11FMT) | |
#define STATE u3 /* unit state */ | |
#define LASTT u4 /* last time update */ | |
#define WRITTEN u5 /* device buffer is dirty and needs flushing */ | |
#define DT_WC 030 /* word count */ | |
#define DT_CA 031 /* current addr */ | |
#define UNIT_WPRT (UNIT_WLK | UNIT_RO) /* write protect */ | |
/* System independent DECtape constants */ | |
#define DT_LPERMC 6 /* lines per mark track */ | |
#define DT_BLKWD 1 /* blk no word in h/t */ | |
#define DT_CSMWD 4 /* checksum word in h/t */ | |
#define DT_HTWRD 5 /* header/trailer words */ | |
#define DT_EZLIN (8192 * DT_LPERMC) /* end zone length */ | |
#define DT_BFLIN (200 * DT_LPERMC) /* buffer length */ | |
#define DT_BLKLN (DT_BLKWD * DT_LPERMC) /* blk no line in h/t */ | |
#define DT_CSMLN (DT_CSMWD * DT_LPERMC) /* csum line in h/t */ | |
#define DT_HTLIN (DT_HTWRD * DT_LPERMC) /* header/trailer lines */ | |
/* 16b, 18b, 36b DECtape constants */ | |
#define D18_WSIZE 6 /* word size in lines */ | |
#define D18_BSIZE 256 /* block size in 18b */ | |
#define D18_TSIZE 578 /* tape size */ | |
#define D18_LPERB (DT_HTLIN + (D18_BSIZE * DT_WSIZE) + DT_HTLIN) | |
#define D18_FWDEZ (DT_EZLIN + (D18_LPERB * D18_TSIZE)) | |
#define D18_CAPAC (D18_TSIZE * D18_BSIZE) /* tape capacity */ | |
#define D11_FILSIZ (D18_CAPAC * sizeof (int16)) | |
/* 12b DECtape constants */ | |
#define D8_WSIZE 4 /* word size in lines */ | |
#define D8_BSIZE 86 /* block size in 18b */ | |
#define D8_TSIZE 1474 /* tape size */ | |
#define D8_LPERB (DT_HTLIN + (D8_BSIZE * DT_WSIZE) + DT_HTLIN) | |
#define D8_FWDEZ (DT_EZLIN + (D8_LPERB * D8_TSIZE)) | |
#define D8_CAPAC (D8_TSIZE * D8_BSIZE) /* tape capacity */ | |
#define D8_NBSIZE ((D8_BSIZE * D18_WSIZE) / D8_WSIZE) | |
#define D8_FILSIZ (D8_NBSIZE * D8_TSIZE * sizeof (int16)) | |
/* This controller */ | |
#define DT_CAPAC D18_CAPAC /* default */ | |
#define DT_WSIZE D18_WSIZE | |
/* Calculated constants, per unit */ | |
#define DTU_BSIZE(u) (((u)->flags & UNIT_8FMT)? D8_BSIZE: D18_BSIZE) | |
#define DTU_TSIZE(u) (((u)->flags & UNIT_8FMT)? D8_TSIZE: D18_TSIZE) | |
#define DTU_LPERB(u) (((u)->flags & UNIT_8FMT)? D8_LPERB: D18_LPERB) | |
#define DTU_FWDEZ(u) (((u)->flags & UNIT_8FMT)? D8_FWDEZ: D18_FWDEZ) | |
#define DTU_CAPAC(u) (((u)->flags & UNIT_8FMT)? D8_CAPAC: D18_CAPAC) | |
#define DT_LIN2BL(p,u) (((p) - DT_EZLIN) / DTU_LPERB (u)) | |
#define DT_LIN2OF(p,u) (((p) - DT_EZLIN) % DTU_LPERB (u)) | |
#define DT_LIN2WD(p,u) ((DT_LIN2OF (p,u) - DT_HTLIN) / DT_WSIZE) | |
#define DT_BLK2LN(p,u) (((p) * DTU_LPERB (u)) + DT_EZLIN) | |
#define DT_QREZ(u) (((u)->pos) < DT_EZLIN) | |
#define DT_QFEZ(u) (((u)->pos) >= ((uint32) DTU_FWDEZ (u))) | |
#define DT_QEZ(u) (DT_QREZ (u) || DT_QFEZ (u)) | |
/* Status register A */ | |
#if defined (TC02) /* TC02/TC15 */ | |
#define DTA_V_UNIT 15 /* unit select */ | |
#define DTA_M_UNIT 07 | |
#define DTA_UNIT (DTA_M_UNIT << DTA_V_UNIT) | |
#define DTA_V_MOT 13 /* motion */ | |
#define DTA_M_MOT 03 | |
#define DTA_V_MODE 12 /* mode */ | |
#define DTA_V_FNC 9 /* function */ | |
#define DTA_M_FNC 07 | |
#define FNC_MOVE 00 /* move */ | |
#define FNC_SRCH 01 /* search */ | |
#define FNC_READ 02 /* read */ | |
#define FNC_RALL 03 /* read all */ | |
#define FNC_WRIT 04 /* write */ | |
#define FNC_WALL 05 /* write all */ | |
#define FNC_WMRK 06 /* write timing */ | |
#define DTA_V_ENB 8 /* int enable */ | |
#define DTA_V_CERF 7 /* clr error flag */ | |
#define DTA_V_CDTF 6 /* clr DECtape flag */ | |
#define DTA_FWDRV (1u << (DTA_V_MOT + 1)) | |
#define DTA_STSTP (1u << DTA_V_MOT) | |
#define DTA_MODE (1u << DTA_V_MODE) | |
#define DTA_ENB (1u << DTA_V_ENB) | |
#define DTA_CERF (1u << DTA_V_CERF) | |
#define DTA_CDTF (1u << DTA_V_CDTF) | |
#define DTA_RW (0777700 & ~(DTA_CERF | DTA_CDTF)) | |
#define DTA_GETUNIT(x) (((x) >> DTA_V_UNIT) & DTA_M_UNIT) | |
#define DT_UPDINT if ((dtsa & DTA_ENB) && (dtsb & (DTB_ERF | DTB_DTF))) \ | |
SET_INT (DTA); \ | |
else CLR_INT (DTA); | |
#else /* Type 550 */ | |
#define DTA_V_UNIT 12 /* unit select */ | |
#define DTA_M_UNIT 017 | |
#define DTA_UNIT (DTA_M_UNIT << DTA_V_UNIT) | |
#define DTA_V_MOT 4 /* motion */ | |
#define DTA_M_MOT 03 | |
#define DTA_V_FNC 0 /* function */ | |
#define DTA_M_FNC 07 | |
#define FNC_MOVE 00 /* move */ | |
#define FNC_SRCH 01 /* search */ | |
#define FNC_READ 02 /* read */ | |
#define FNC_WRIT 03 /* write */ | |
#define FNC_RALL 05 /* read all */ | |
#define FNC_WALL 06 /* write all */ | |
#define FNC_WMRK 07 /* write timing */ | |
#define DTA_STSTP (1u << (DTA_V_MOT + 1)) | |
#define DTA_FWDRV (1u << DTA_V_MOT) | |
#define DTA_MODE 0 /* not implemented */ | |
#define DTA_RW 077 | |
#define DTA_GETUNIT(x) map_unit[(((x) >> DTA_V_UNIT) & DTA_M_UNIT)] | |
#define DT_UPDINT if (dtsb & (DTB_DTF | DTB_BEF | DTB_ERF)) \ | |
SET_INT (DTA); \ | |
else CLR_INT (DTA); | |
#endif | |
#define DTA_GETMOT(x) (((x) >> DTA_V_MOT) & DTA_M_MOT) | |
#define DTA_GETFNC(x) (((x) >> DTA_V_FNC) & DTA_M_FNC) | |
/* Status register B */ | |
#if defined (TC02) /* TC02/TC15 */ | |
#define DTB_V_ERF 17 /* error flag */ | |
#define DTB_V_MRK 16 /* mark trk err */ | |
#define DTB_V_END 15 /* end zone err */ | |
#define DTB_V_SEL 14 /* select err */ | |
#define DTB_V_PAR 13 /* parity err */ | |
#define DTB_V_TIM 12 /* timing err */ | |
#define DTB_V_DTF 6 /* DECtape flag */ | |
#define DTB_ERF (1u << DTB_V_ERF) | |
#define DTB_MRK (1u << DTB_V_MRK) | |
#define DTB_END (1u << DTB_V_END) | |
#define DTB_SEL (1u << DTB_V_SEL) | |
#define DTB_PAR (1u << DTB_V_PAR) | |
#define DTB_TIM (1u << DTB_V_TIM) | |
#define DTB_DTF (1u << DTB_V_DTF) | |
#define DTB_ALLERR (DTB_ERF | DTB_MRK | DTB_END | DTB_SEL | \ | |
DTB_PAR | DTB_TIM) | |
#else /* Type 550 */ | |
#define DTB_V_DTF 17 /* data flag */ | |
#define DTB_V_BEF 16 /* block end flag */ | |
#define DTB_V_ERF 15 /* error flag */ | |
#define DTB_V_END 14 /* end of tape */ | |
#define DTB_V_TIM 13 /* timing err */ | |
#define DTB_V_REV 12 /* reverse */ | |
#define DTB_V_GO 11 /* go */ | |
#define DTB_V_MRK 10 /* mark trk err */ | |
#define DTB_V_SEL 9 /* select err */ | |
#define DTB_DTF (1u << DTB_V_DTF) | |
#define DTB_BEF (1u << DTB_V_BEF) | |
#define DTB_ERF (1u << DTB_V_ERF) | |
#define DTB_END (1u << DTB_V_END) | |
#define DTB_TIM (1u << DTB_V_TIM) | |
#define DTB_REV (1u << DTB_V_REV) | |
#define DTB_GO (1u << DTB_V_GO) | |
#define DTB_MRK (1u << DTB_V_MRK) | |
#define DTB_SEL (1u << DTB_V_SEL) | |
#define DTB_ALLERR (DTB_END | DTB_TIM | DTB_MRK | DTB_SEL) | |
#endif | |
/* DECtape state */ | |
#define DTS_V_MOT 3 /* motion */ | |
#define DTS_M_MOT 07 | |
#define DTS_STOP 0 /* stopped */ | |
#define DTS_DECF 2 /* decel, fwd */ | |
#define DTS_DECR 3 /* decel, rev */ | |
#define DTS_ACCF 4 /* accel, fwd */ | |
#define DTS_ACCR 5 /* accel, rev */ | |
#define DTS_ATSF 6 /* @speed, fwd */ | |
#define DTS_ATSR 7 /* @speed, rev */ | |
#define DTS_DIR 01 /* dir mask */ | |
#define DTS_V_FNC 0 /* function */ | |
#define DTS_M_FNC 07 | |
#define DTS_OFR 7 /* "off reel" */ | |
#define DTS_GETMOT(x) (((x) >> DTS_V_MOT) & DTS_M_MOT) | |
#define DTS_GETFNC(x) (((x) >> DTS_V_FNC) & DTS_M_FNC) | |
#define DTS_V_2ND 6 /* next state */ | |
#define DTS_V_3RD (DTS_V_2ND + DTS_V_2ND) /* next next */ | |
#define DTS_STA(y,z) (((y) << DTS_V_MOT) | ((z) << DTS_V_FNC)) | |
#define DTS_SETSTA(y,z) uptr->STATE = DTS_STA (y, z) | |
#define DTS_SET2ND(y,z) uptr->STATE = (uptr->STATE & 077) | \ | |
((DTS_STA (y, z)) << DTS_V_2ND) | |
#define DTS_SET3RD(y,z) uptr->STATE = (uptr->STATE & 07777) | \ | |
((DTS_STA (y, z)) << DTS_V_3RD) | |
#define DTS_NXTSTA(x) (x >> DTS_V_2ND) | |
/* Operation substates */ | |
#define DTO_WCO 1 /* wc overflow */ | |
#define DTO_SOB 2 /* start of block */ | |
/* Logging */ | |
#define LOG_MS 001 /* move, search */ | |
#define LOG_RW 002 /* read, write */ | |
#define LOG_RA 004 /* read all */ | |
#define LOG_BL 010 /* block # lblk */ | |
#define ABS(x) (((x) < 0)? (-(x)): (x)) | |
extern int32 M[]; | |
extern int32 int_hwre[API_HLVL+1]; | |
extern UNIT cpu_unit; | |
int32 dtsa = 0; /* status A */ | |
int32 dtsb = 0; /* status B */ | |
int32 dtdb = 0; /* data buffer */ | |
int32 dt_ltime = 12; /* interline time */ | |
int32 dt_dctime = 40000; /* decel time */ | |
int32 dt_substate = 0; | |
int32 dt_logblk = 0; | |
int32 dt_stopoffr = 0; /* stop on off reel */ | |
static const int32 map_unit[16] = { /* Type 550 unit map */ | |
-1, 1, 2, 3, 4, 5, 6, 7, | |
0, -1, -1, -1, -1, -1, -1, -1 | |
}; | |
DEVICE dt_dev; | |
int32 dt75 (int32 dev, int32 pulse, int32 dat); | |
int32 dt76 (int32 dev, int32 pulse, int32 dat); | |
int32 dt_iors (void); | |
t_stat dt_svc (UNIT *uptr); | |
t_stat dt_reset (DEVICE *dptr); | |
t_stat dt_attach (UNIT *uptr, char *cptr); | |
void dt_flush (UNIT *uptr); | |
t_stat dt_detach (UNIT *uptr); | |
void dt_deselect (int32 oldf); | |
void dt_newsa (int32 newf); | |
void dt_newfnc (UNIT *uptr, int32 newsta); | |
t_bool dt_setpos (UNIT *uptr); | |
void dt_schedez (UNIT *uptr, int32 dir); | |
void dt_seterr (UNIT *uptr, int32 e); | |
int32 dt_comobv (int32 val); | |
int32 dt_csum (UNIT *uptr, int32 blk); | |
int32 dt_gethdr (UNIT *uptr, int32 blk, int32 relpos); | |
/* DT data structures | |
dt_dev DT device descriptor | |
dt_unit DT unit list | |
dt_reg DT register list | |
dt_mod DT modifier list | |
*/ | |
DIB dt_dib = { DEV_DTA, 2, &dt_iors, { &dt75, &dt76 } }; | |
UNIT dt_unit[] = { | |
{ UDATAFLUSH (&dt_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_DISABLE+ | |
UNIT_ROABLE, DT_CAPAC, &dt_flush) }, | |
{ UDATAFLUSH (&dt_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_DISABLE+ | |
UNIT_ROABLE, DT_CAPAC, &dt_flush) }, | |
{ UDATAFLUSH (&dt_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_DISABLE+ | |
UNIT_ROABLE, DT_CAPAC, &dt_flush) }, | |
{ UDATAFLUSH (&dt_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_DISABLE+ | |
UNIT_ROABLE, DT_CAPAC, &dt_flush) }, | |
{ UDATAFLUSH (&dt_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_DISABLE+ | |
UNIT_ROABLE, DT_CAPAC, &dt_flush) }, | |
{ UDATAFLUSH (&dt_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_DISABLE+ | |
UNIT_ROABLE, DT_CAPAC, &dt_flush) }, | |
{ UDATAFLUSH (&dt_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_DISABLE+ | |
UNIT_ROABLE, DT_CAPAC, &dt_flush) }, | |
{ UDATAFLUSH (&dt_svc, UNIT_FIX+UNIT_ATTABLE+UNIT_DISABLE+ | |
UNIT_ROABLE, DT_CAPAC, &dt_flush) } | |
}; | |
REG dt_reg[] = { | |
{ ORDATA (DTSA, dtsa, 18) }, | |
{ ORDATA (DTSB, dtsb, 18) }, | |
{ ORDATA (DTDB, dtdb, 18) }, | |
{ FLDATA (INT, int_hwre[API_DTA], INT_V_DTA) }, | |
#if defined (DTA_V_ENB) | |
{ FLDATA (ENB, dtsa, DTA_V_ENB) }, | |
#endif | |
{ FLDATA (DTF, dtsb, DTB_V_DTF) }, | |
#if defined (DTB_V_BEF) | |
{ FLDATA (BEF, dtsb, DTB_V_BEF) }, | |
#endif | |
{ FLDATA (ERF, dtsb, DTB_V_ERF) }, | |
#if defined (TC02) /* TC02/TC15 */ | |
{ ORDATA (WC, M[DT_WC], 18) }, | |
{ ORDATA (CA, M[DT_CA], 18) }, | |
#endif | |
{ DRDATA (LTIME, dt_ltime, 31), REG_NZ }, | |
{ DRDATA (DCTIME, dt_dctime, 31), REG_NZ }, | |
{ ORDATA (SUBSTATE, dt_substate, 2) }, | |
{ DRDATA (LBLK, dt_logblk, 12), REG_HIDDEN }, | |
{ URDATA (POS, dt_unit[0].pos, 10, T_ADDR_W, 0, | |
DT_NUMDR, PV_LEFT | REG_RO) }, | |
{ URDATA (STATT, dt_unit[0].STATE, 8, 18, 0, | |
DT_NUMDR, REG_RO) }, | |
{ URDATA (LASTT, dt_unit[0].LASTT, 10, T_ADDR_W, 0, | |
DT_NUMDR, REG_HRO) }, | |
{ ORDATA (DEVNO, dt_dib.dev, 6), REG_HRO }, | |
{ FLDATA (STOP_OFFR, dt_stopoffr, 0) }, | |
{ NULL } | |
}; | |
MTAB dt_mod[] = { | |
{ UNIT_WLK, 0, "write enabled", "WRITEENABLED", NULL }, | |
{ UNIT_WLK, UNIT_WLK, "write locked", "LOCKED", NULL }, | |
{ UNIT_8FMT + UNIT_11FMT, 0, "18b", NULL, NULL }, | |
{ UNIT_8FMT + UNIT_11FMT, UNIT_8FMT, "12b", NULL, NULL }, | |
{ UNIT_8FMT + UNIT_11FMT, UNIT_11FMT, "16b", NULL, NULL }, | |
{ MTAB_XTD|MTAB_VDV, 0, "DEVNO", "DEVNO", &set_devno, &show_devno }, | |
{ 0 } | |
}; | |
DEBTAB dt_deb[] = { | |
{ "MOTION", LOG_MS }, | |
{ "DATA", LOG_RW }, | |
{ "READALL", LOG_RA }, | |
{ "BLOCK", LOG_BL }, | |
{ NULL, 0 } | |
}; | |
DEVICE dt_dev = { | |
"DT", dt_unit, dt_reg, dt_mod, | |
DT_NUMDR, 8, 24, 1, 8, 18, | |
NULL, NULL, &dt_reset, | |
NULL, &dt_attach, &dt_detach, | |
&dt_dib, DEV_DISABLE | DEV_DEBUG, 0, | |
dt_deb, NULL, NULL | |
}; | |
/* IOT routines */ | |
#if defined (TC02) /* TC02/TC15 */ | |
int32 dt75 (int32 dev, int32 pulse, int32 dat) | |
{ | |
int32 old_dtsa = dtsa, fnc; | |
UNIT *uptr; | |
if (((pulse & 060) == 040) && (pulse & 05)) { /* select */ | |
if (pulse & 01) /* DTCA */ | |
dtsa = 0; | |
if (pulse & 02) /* DTRA!... */ | |
dat = dtsa; | |
if (pulse & 04) { /* DTXA */ | |
if ((dat & DTA_CERF) == 0) | |
dtsb = dtsb & ~DTB_ALLERR; | |
if ((dat & DTA_CDTF) == 0) | |
dtsb = dtsb & ~DTB_DTF; | |
dtsa = dtsa ^ (dat & DTA_RW); | |
} | |
if ((old_dtsa ^ dtsa) & DTA_UNIT) | |
dt_deselect (old_dtsa); | |
uptr = dt_dev.units + DTA_GETUNIT (dtsa); /* get unit */ | |
fnc = DTA_GETFNC (dtsa); /* get fnc */ | |
if (((uptr->flags) & UNIT_DIS) || /* disabled? */ | |
(fnc >= FNC_WMRK) || /* write mark? */ | |
((fnc == FNC_WRIT) && (uptr->flags & UNIT_WPRT)) || | |
((fnc == FNC_WALL) && (uptr->flags & UNIT_WPRT))) | |
dt_seterr (uptr, DTB_SEL); /* select err */ | |
else dt_newsa (dtsa); /* new func */ | |
DT_UPDINT; | |
return dat; | |
} | |
if ((pulse & 067) == 042) /* DTRA */ | |
return dtsa; | |
if ((pulse & 067) == 061) /* DTEF */ | |
return ((dtsb & DTB_ERF)? IOT_SKP + dat: dat); | |
if ((pulse & 067) == 062) /* DTRB */ | |
return dtsb; | |
if ((pulse & 067) == 063) /* DTEF!DTRB */ | |
return ((dtsb & DTB_ERF)? IOT_SKP + dtsb: dtsb); | |
return dat; | |
} | |
int32 dt76 (int32 dev, int32 pulse, int32 dat) | |
{ | |
if ((pulse & 01) && (dtsb & DTB_DTF)) /* DTDF */ | |
return IOT_SKP + dat; | |
return dat; | |
} | |
#else /* Type 550 */ | |
int32 dt75 (int32 dev, int32 pulse, int32 dat) | |
{ | |
if (((pulse & 041) == 001) && (dtsb & DTB_DTF)) /* MMDF */ | |
dat = dat | IOT_SKP; | |
else if (((pulse & 041) == 041) && (dtsb & DTB_ERF)) /* MMEF */ | |
dat = dat | IOT_SKP; | |
if (pulse & 002) { /* MMRD */ | |
dat = (dat & ~DMASK) | dtdb; | |
dtsb = dtsb & ~(DTB_DTF | DTB_BEF); | |
} | |
if (pulse & 004) { /* MMWR */ | |
dtdb = dat & DMASK; | |
dtsb = dtsb & ~(DTB_DTF | DTB_BEF); | |
} | |
DT_UPDINT; | |
return dat; | |
} | |
int32 dt76 (int32 dev, int32 pulse, int32 dat) | |
{ | |
int32 fnc, mot, unum; | |
UNIT *uptr = NULL; | |
unum = DTA_GETUNIT (dtsa); /* get unit no */ | |
if (unum >= 0) /* get unit */ | |
uptr = dt_dev.units + unum; | |
if ((pulse & 001) && (dtsb & DTB_BEF)) /* MMBF */ | |
dat = dat | IOT_SKP; | |
if (pulse & 002) { /* MMRS */ | |
dtsb = dtsb & ~(DTB_REV | DTB_GO); /* clr rev, go */ | |
if (uptr) { /* valid unit? */ | |
mot = DTS_GETMOT (uptr->STATE); /* get motion */ | |
if (mot & DTS_DIR) /* rev? set */ | |
dtsb = dtsb | DTB_REV; | |
if ((mot >= DTS_ACCF) || (uptr->STATE & 0777700)) | |
dtsb = dtsb | DTB_GO; /* accel? go */ | |
} | |
dat = (dat & ~DMASK) | dtsb; | |
} | |
if ((pulse & 044) == 044) { /* MMSE */ | |
if ((dtsa ^ dat) & DTA_UNIT) /* new unit? */ | |
dt_deselect (dtsa); | |
dtsa = (dtsa & ~DTA_UNIT) | (dat & DTA_UNIT); | |
dtsb = dtsb & ~(DTB_DTF | DTB_BEF | DTB_ERF | DTB_ALLERR); | |
} | |
else if ((pulse & 044) == 004) { /* MMLC */ | |
dtsa = (dtsa & ~DTA_RW) | (dat & DTA_RW); /* load dtsa */ | |
dtsb = dtsb & ~(DTB_DTF | DTB_BEF | DTB_ERF | DTB_ALLERR); | |
fnc = DTA_GETFNC (dtsa); /* get fnc */ | |
if ((uptr == NULL) || /* invalid? */ | |
((uptr->flags) & UNIT_DIS) || /* disabled? */ | |
(fnc >= FNC_WMRK) || /* write mark? */ | |
((fnc == FNC_WRIT) && (uptr->flags & UNIT_WLK)) || | |
((fnc == FNC_WALL) && (uptr->flags & UNIT_WLK))) | |
dt_seterr (uptr, DTB_SEL); /* select err */ | |
else dt_newsa (dtsa); | |
} | |
DT_UPDINT; | |
return dat; | |
} | |
#endif | |
/* Unit deselect */ | |
void dt_deselect (int32 oldf) | |
{ | |
int32 old_unit, old_mot; | |
UNIT *uptr; | |
old_unit = DTA_GETUNIT (oldf); /* get unit no */ | |
if (old_unit < 0) /* invalid? */ | |
return; | |
uptr = dt_dev.units + old_unit; /* get unit */ | |
old_mot = DTS_GETMOT (uptr->STATE); | |
if (old_mot >= DTS_ATSF) /* at speed? */ | |
dt_newfnc (uptr, DTS_STA (old_mot, DTS_OFR)); | |
else if (old_mot >= DTS_ACCF) /* accelerating? */ | |
DTS_SET2ND (DTS_ATSF | (old_mot & DTS_DIR), DTS_OFR); | |
return; | |
} | |
/* Command register change | |
1. If change in motion, stop to start | |
- schedule acceleration | |
- set function as next state | |
2. If change in motion, start to stop | |
- if not already decelerating (could be reversing), | |
schedule deceleration | |
3. If change in direction, | |
- if not decelerating, schedule deceleration | |
- set accelerating (other dir) as next state | |
- set function as next next state | |
4. If not accelerating or at speed, | |
- schedule acceleration | |
- set function as next state | |
5. If not yet at speed, | |
- set function as next state | |
6. If at speed, | |
- set function as current state, schedule function | |
*/ | |
void dt_newsa (int32 newf) | |
{ | |
int32 new_unit, prev_mot, new_fnc; | |
int32 prev_mving, new_mving, prev_dir, new_dir; | |
UNIT *uptr; | |
new_unit = DTA_GETUNIT (newf); /* new unit */ | |
if (new_unit < 0) /* invalid? */ | |
return; | |
uptr = dt_dev.units + new_unit; | |
if ((uptr->flags & UNIT_ATT) == 0) { /* new unit attached? */ | |
dt_seterr (uptr, DTB_SEL); /* no, error */ | |
return; | |
} | |
prev_mot = DTS_GETMOT (uptr->STATE); /* previous motion */ | |
prev_mving = prev_mot != DTS_STOP; /* previous moving? */ | |
prev_dir = prev_mot & DTS_DIR; /* previous dir? */ | |
new_mving = (newf & DTA_STSTP) != 0; /* new moving? */ | |
new_dir = (newf & DTA_FWDRV) != 0; /* new dir? */ | |
new_fnc = DTA_GETFNC (newf); /* new function? */ | |
if ((prev_mving | new_mving) == 0) /* stop to stop */ | |
return; | |
if (new_mving & ~prev_mving) { /* start? */ | |
if (dt_setpos (uptr)) /* update pos */ | |
return; | |
sim_cancel (uptr); /* stop current */ | |
sim_activate (uptr, dt_dctime - (dt_dctime >> 2)); /* sched accel */ | |
DTS_SETSTA (DTS_ACCF | new_dir, 0); /* state = accel */ | |
DTS_SET2ND (DTS_ATSF | new_dir, new_fnc); /* next = fnc */ | |
return; | |
} | |
if (prev_mving & ~new_mving) { /* stop? */ | |
if ((prev_mot & ~DTS_DIR) != DTS_DECF) { /* !already stopping? */ | |
if (dt_setpos (uptr)) /* update pos */ | |
return; | |
sim_cancel (uptr); /* stop current */ | |
sim_activate (uptr, dt_dctime); /* schedule decel */ | |
} | |
DTS_SETSTA (DTS_DECF | prev_dir, 0); /* state = decel */ | |
return; | |
} | |
if (prev_dir ^ new_dir) { /* dir chg? */ | |
if ((prev_mot & ~DTS_DIR) != DTS_DECF) { /* !already stopping? */ | |
if (dt_setpos (uptr)) /* update pos */ | |
return; | |
sim_cancel (uptr); /* stop current */ | |
sim_activate (uptr, dt_dctime); /* schedule decel */ | |
} | |
DTS_SETSTA (DTS_DECF | prev_dir, 0); /* state = decel */ | |
DTS_SET2ND (DTS_ACCF | new_dir, 0); /* next = accel */ | |
DTS_SET3RD (DTS_ATSF | new_dir, new_fnc); /* next next = fnc */ | |
return; | |
} | |
if (prev_mot < DTS_ACCF) { /* not accel/at speed? */ | |
if (dt_setpos (uptr)) /* update pos */ | |
return; | |
sim_cancel (uptr); /* cancel cur */ | |
sim_activate (uptr, dt_dctime - (dt_dctime >> 2)); /* sched accel */ | |
DTS_SETSTA (DTS_ACCF | new_dir, 0); /* state = accel */ | |
DTS_SET2ND (DTS_ATSF | new_dir, new_fnc); /* next = fnc */ | |
return; | |
} | |
if (prev_mot < DTS_ATSF) { /* not at speed? */ | |
DTS_SET2ND (DTS_ATSF | new_dir, new_fnc); /* next = fnc */ | |
return; | |
} | |
dt_newfnc (uptr, DTS_STA (DTS_ATSF | new_dir, new_fnc));/* state = fnc */ | |
return; | |
} | |
/* Schedule new DECtape function | |
This routine is only called if | |
- the selected unit is attached | |
- the selected unit is at speed (forward or backward) | |
This routine | |
- updates the selected unit's position | |
- updates the selected unit's state | |
- schedules the new operation | |
*/ | |
void dt_newfnc (UNIT *uptr, int32 newsta) | |
{ | |
int32 fnc, dir, blk, unum, newpos; | |
#if defined (TC02) | |
int32 relpos; | |
#endif | |
uint32 oldpos; | |
oldpos = uptr->pos; /* save old pos */ | |
if (dt_setpos (uptr)) /* update pos */ | |
return; | |
uptr->STATE = newsta; /* update state */ | |
fnc = DTS_GETFNC (uptr->STATE); /* set variables */ | |
dir = DTS_GETMOT (uptr->STATE) & DTS_DIR; | |
unum = (int32) (uptr - dt_dev.units); | |
if (oldpos == uptr->pos) /* bump pos */ | |
uptr->pos = uptr->pos + (dir? -1: 1); | |
blk = DT_LIN2BL (uptr->pos, uptr); | |
if (dir? DT_QREZ (uptr): DT_QFEZ (uptr)) { /* wrong ez? */ | |
dt_seterr (uptr, DTB_END); /* set ez flag, stop */ | |
return; | |
} | |
sim_cancel (uptr); /* cancel cur op */ | |
dt_substate = DTO_SOB; /* substate = block start */ | |
switch (fnc) { /* case function */ | |
case DTS_OFR: /* off reel */ | |
if (dir) /* rev? < start */ | |
newpos = -1000; | |
else newpos = DTU_FWDEZ (uptr) + DT_EZLIN + 1000; /* fwd? > end */ | |
break; | |
case FNC_MOVE: /* move */ | |
dt_schedez (uptr, dir); /* sched end zone */ | |
if (DEBUG_PRI (dt_dev, LOG_MS)) | |
fprintf (sim_deb, ">>DT%d: moving %s\n", | |
unum, (dir? "backward": "forward")); | |
return; /* done */ | |
case FNC_SRCH: /* search */ | |
if (dir) | |
newpos = DT_BLK2LN ((DT_QFEZ (uptr)? | |
DTU_TSIZE (uptr): blk), uptr) - DT_BLKLN - DT_WSIZE; | |
else newpos = DT_BLK2LN ((DT_QREZ (uptr)? | |
0: blk + 1), uptr) + DT_BLKLN + (DT_WSIZE - 1); | |
if (DEBUG_PRI (dt_dev, LOG_MS)) | |
fprintf (sim_deb, ">>DT%d: searching %s\n", unum, | |
(dir? "backward": "forward")); | |
break; | |
case FNC_WRIT: /* write */ | |
case FNC_READ: /* read */ | |
#if defined (TC02) /* TC02/TC15 */ | |
if (DT_QEZ (uptr)) { /* in "ok" end zone? */ | |
if (dir) | |
newpos = DTU_FWDEZ (uptr) - DT_HTLIN - DT_WSIZE; | |
else newpos = DT_EZLIN + DT_HTLIN + (DT_WSIZE - 1); | |
break; | |
} | |
relpos = DT_LIN2OF (uptr->pos, uptr); /* cur pos in blk */ | |
if ((relpos >= DT_HTLIN) && /* in data zone? */ | |
(relpos < (DTU_LPERB (uptr) - DT_HTLIN))) { | |
dt_seterr (uptr, DTB_SEL); | |
return; | |
} | |
if (dir) | |
newpos = DT_BLK2LN (((relpos >= (DTU_LPERB (uptr) - DT_HTLIN))? | |
blk + 1: blk), uptr) - DT_HTLIN - DT_WSIZE; | |
else newpos = DT_BLK2LN (((relpos < DT_HTLIN)? | |
blk: blk + 1), uptr) + DT_HTLIN + (DT_WSIZE - 1); | |
break; | |
#endif | |
case FNC_RALL: /* read all */ | |
case FNC_WALL: /* write all */ | |
if (DT_QEZ (uptr)) { /* in "ok" end zone? */ | |
if (dir) | |
newpos = DTU_FWDEZ (uptr) - DT_WSIZE; | |
else newpos = DT_EZLIN + (DT_WSIZE - 1); | |
} | |
else { | |
newpos = ((uptr->pos) / DT_WSIZE) * DT_WSIZE; | |
if (!dir) | |
newpos = newpos + (DT_WSIZE - 1); | |
} | |
if (DEBUG_PRI (dt_dev, LOG_RA) || | |
(DEBUG_PRI (dt_dev, LOG_BL) && (blk == dt_logblk))) | |
fprintf (sim_deb, ">>DT%d: read all block %d %s%s\n", | |
unum, blk, (dir? "backward": "forward"), | |
((dtsa & DTA_MODE)? " continuous]": " ")); | |
break; | |
default: | |
dt_seterr (uptr, DTB_SEL); /* bad state */ | |
return; | |
} | |
#if defined (TYPE550) /* Type 550 */ | |
if ((fnc == FNC_WRIT) || (fnc == FNC_WALL)) { /* write function? */ | |
dtsb = dtsb | DTB_DTF; /* set data flag */ | |
DT_UPDINT; | |
} | |
#endif | |
sim_activate (uptr, ABS (newpos - ((int32) uptr->pos)) * dt_ltime); | |
return; | |
} | |
/* Update DECtape position | |
DECtape motion is modeled as a constant velocity, with linear | |
acceleration and deceleration. The motion equations are as follows: | |
t = time since operation started | |
tmax = time for operation (accel, decel only) | |
v = at speed velocity in lines (= 1/dt_ltime) | |
Then: | |
at speed dist = t * v | |
accel dist = (t^2 * v) / (2 * tmax) | |
decel dist = (((2 * t * tmax) - t^2) * v) / (2 * tmax) | |
This routine uses the relative (integer) time, rather than the absolute | |
(floating point) time, to allow save and restore of the start times. | |
*/ | |
t_bool dt_setpos (UNIT *uptr) | |
{ | |
uint32 new_time, ut, ulin, udelt; | |
int32 mot = DTS_GETMOT (uptr->STATE); | |
int32 unum, delta; | |
new_time = sim_grtime (); /* current time */ | |
ut = new_time - uptr->LASTT; /* elapsed time */ | |
if (ut == 0) /* no time gone? exit */ | |
return FALSE; | |
uptr->LASTT = new_time; /* update last time */ | |
switch (mot & ~DTS_DIR) { /* case on motion */ | |
case DTS_STOP: /* stop */ | |
delta = 0; | |
break; | |
case DTS_DECF: /* slowing */ | |
ulin = ut / (uint32) dt_ltime; | |
udelt = dt_dctime / dt_ltime; | |
delta = ((ulin * udelt * 2) - (ulin * ulin)) / (2 * udelt); | |
break; | |
case DTS_ACCF: /* accelerating */ | |
ulin = ut / (uint32) dt_ltime; | |
udelt = (dt_dctime - (dt_dctime >> 2)) / dt_ltime; | |
delta = (ulin * ulin) / (2 * udelt); | |
break; | |
case DTS_ATSF: /* at speed */ | |
delta = ut / (uint32) dt_ltime; | |
break; | |
} | |
if (mot & DTS_DIR) /* update pos */ | |
uptr->pos = uptr->pos - delta; | |
else uptr->pos = uptr->pos + delta; | |
if (((int32) uptr->pos < 0) || | |
((int32) uptr->pos > (DTU_FWDEZ (uptr) + DT_EZLIN))) { | |
detach_unit (uptr); /* off reel? */ | |
uptr->STATE = uptr->pos = 0; | |
unum = (int32) (uptr - dt_dev.units); | |
if (unum == DTA_GETUNIT (dtsa)) /* if selected, */ | |
dt_seterr (uptr, DTB_SEL); /* error */ | |
return TRUE; | |
} | |
return FALSE; | |
} | |
/* Unit service | |
Unit must be attached, detach cancels operation | |
*/ | |
t_stat dt_svc (UNIT *uptr) | |
{ | |
int32 mot = DTS_GETMOT (uptr->STATE); | |
int32 dir = mot & DTS_DIR; | |
int32 fnc = DTS_GETFNC (uptr->STATE); | |
int32 *fbuf = (int32 *) uptr->filebuf; | |
int32 unum = uptr - dt_dev.units; | |
int32 blk, wrd, ma, relpos; | |
uint32 ba; | |
/* Motion cases | |
Decelerating - if next state != stopped, must be accel reverse | |
Accelerating - next state must be @speed, schedule function | |
At speed - do functional processing | |
*/ | |
switch (mot) { | |
case DTS_DECF: case DTS_DECR: /* decelerating */ | |
if (dt_setpos (uptr)) /* upd pos; off reel? */ | |
return IORETURN (dt_stopoffr, STOP_DTOFF); | |
uptr->STATE = DTS_NXTSTA (uptr->STATE); /* advance state */ | |
if (uptr->STATE) /* not stopped? */ | |
sim_activate (uptr, dt_dctime - (dt_dctime >> 2)); /* reversing */ | |
return SCPE_OK; | |
case DTS_ACCF: case DTS_ACCR: /* accelerating */ | |
dt_newfnc (uptr, DTS_NXTSTA (uptr->STATE)); /* adv state, sched */ | |
return SCPE_OK; | |
case DTS_ATSF: case DTS_ATSR: /* at speed */ | |
break; /* check function */ | |
default: /* other */ | |
dt_seterr (uptr, DTB_SEL); /* state error */ | |
return SCPE_OK; | |
} | |
/* Functional cases | |
Move - must be at end zone | |
Search - transfer block number, schedule next block | |
Off reel - detach unit (it must be deselected) | |
*/ | |
if (dt_setpos (uptr)) /* upd pos; off reel? */ | |
return IORETURN (dt_stopoffr, STOP_DTOFF); | |
if (DT_QEZ (uptr)) { /* in end zone? */ | |
dt_seterr (uptr, DTB_END); /* end zone error */ | |
return SCPE_OK; | |
} | |
blk = DT_LIN2BL (uptr->pos, uptr); /* get block # */ | |
switch (fnc) { /* at speed, check fnc */ | |
case FNC_MOVE: /* move */ | |
dt_seterr (uptr, DTB_END); /* end zone error */ | |
return SCPE_OK; | |
case DTS_OFR: /* off reel */ | |
detach_unit (uptr); /* must be deselected */ | |
uptr->STATE = uptr->pos = 0; /* no visible action */ | |
break; | |
/* TC02/TC15 service */ | |
/* Search */ | |
#if defined (TC02) /* TC02/TC15 */ | |
case FNC_SRCH: /* search */ | |
if (dtsb & DTB_DTF) { /* DTF set? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
return SCPE_OK; | |
} | |
sim_activate (uptr, DTU_LPERB (uptr) * dt_ltime);/* sched next block */ | |
M[DT_WC] = (M[DT_WC] + 1) & DMASK; /* inc WC */ | |
ma = M[DT_CA] & AMASK; /* get mem addr */ | |
if (MEM_ADDR_OK (ma)) /* store block # */ | |
M[ma] = blk; | |
if (((dtsa & DTA_MODE) == 0) || (M[DT_WC] == 0)) | |
dtsb = dtsb | DTB_DTF; /* set DTF */ | |
if (DEBUG_PRI (dt_dev, LOG_MS)) | |
fprintf (sim_deb, ">>DT%d: found block %d\n", unum, blk); | |
break; | |
/* Read has four subcases | |
Start of block, not wc ovf - check that DTF is clear, otherwise normal | |
Normal - increment MA, WC, copy word from tape to memory | |
if read dir != write dir, bits must be scrambled | |
if wc overflow, next state is wc overflow | |
if end of block, possibly set DTF, next state is start of block | |
Wc ovf, not start of block - | |
if end of block, possibly set DTF, next state is start of block | |
Wc ovf, start of block - if end of block reached, timing error, | |
otherwise, continue to next word | |
*/ | |
case FNC_READ: /* read */ | |
wrd = DT_LIN2WD (uptr->pos, uptr); /* get word # */ | |
switch (dt_substate) { /* case on substate */ | |
case DTO_SOB: /* start of block */ | |
if (dtsb & DTB_DTF) { /* DTF set? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
return SCPE_OK; | |
} | |
if (DEBUG_PRI (dt_dev, LOG_RW) || | |
(DEBUG_PRI (dt_dev, LOG_BL) && (blk == dt_logblk))) | |
fprintf (sim_deb, ">>DT%d: reading block %d %s%s\n", | |
unum, blk, (dir? "backward": "forward"), | |
((dtsa & DTA_MODE)? " continuous": " ")); | |
dt_substate = 0; /* fall through */ | |
case 0: /* normal read */ | |
M[DT_WC] = (M[DT_WC] + 1) & DMASK; /* incr WC, CA */ | |
M[DT_CA] = (M[DT_CA] + 1) & DMASK; | |
ma = M[DT_CA] & AMASK; /* mem addr */ | |
ba = (blk * DTU_BSIZE (uptr)) + wrd; /* buffer ptr */ | |
dtdb = fbuf[ba]; /* get tape word */ | |
if (dir) /* rev? comp obv */ | |
dtdb = dt_comobv (dtdb); | |
if (MEM_ADDR_OK (ma)) /* mem addr legal? */ | |
M[ma] = dtdb; | |
if (M[DT_WC] == 0) /* wc ovf? */ | |
dt_substate = DTO_WCO; | |
case DTO_WCO: /* wc ovf, not sob */ | |
if (wrd != (dir? 0: DTU_BSIZE (uptr) - 1)) /* not last? */ | |
sim_activate (uptr, DT_WSIZE * dt_ltime); | |
else { | |
dt_substate = dt_substate | DTO_SOB; | |
sim_activate (uptr, ((2 * DT_HTLIN) + DT_WSIZE) * dt_ltime); | |
if (((dtsa & DTA_MODE) == 0) || (M[DT_WC] == 0)) | |
dtsb = dtsb | DTB_DTF; /* set DTF */ | |
} | |
break; | |
case DTO_WCO | DTO_SOB: /* next block */ | |
if (wrd == (dir? 0: DTU_BSIZE (uptr))) /* end of block? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
else sim_activate (uptr, DT_WSIZE * dt_ltime); | |
break; | |
} /* end case subst */ | |
break; | |
/* Write has four subcases | |
Start of block, not wc ovf - check that DTF is clear, set block direction | |
Normal - increment MA, WC, copy word from memory to tape | |
if wc overflow, next state is wc overflow | |
if end of block, possibly set DTF, next state is start of block | |
Wc ovf, not start of block - | |
copy 0 to tape | |
if end of block, possibly set DTF, next state is start of block | |
Wc ovf, start of block - schedule end zone | |
*/ | |
case FNC_WRIT: /* write */ | |
wrd = DT_LIN2WD (uptr->pos, uptr); /* get word # */ | |
switch (dt_substate) { /* case on substate */ | |
case DTO_SOB: /* start block */ | |
if (dtsb & DTB_DTF) { /* DTF set? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
return SCPE_OK; | |
} | |
if (DEBUG_PRI (dt_dev, LOG_RW) || | |
(DEBUG_PRI (dt_dev, LOG_BL) && (blk == dt_logblk))) | |
fprintf (sim_deb, ">>DT%d: writing block %d %s%s\n", unum, blk, | |
(dir? "backward": "forward"), | |
((dtsa & DTA_MODE)? " continuous": " ")); | |
dt_substate = 0; /* fall through */ | |
case 0: /* normal write */ | |
M[DT_WC] = (M[DT_WC] + 1) & DMASK; /* incr WC, CA */ | |
M[DT_CA] = (M[DT_CA] + 1) & DMASK; | |
case DTO_WCO: /* wc ovflo */ | |
ma = M[DT_CA] & AMASK; /* mem addr */ | |
ba = (blk * DTU_BSIZE (uptr)) + wrd; /* buffer ptr */ | |
dtdb = dt_substate? 0: M[ma]; /* get word */ | |
if (dir) /* rev? comp obv */ | |
dtdb = dt_comobv (dtdb); | |
fbuf[ba] = dtdb; /* write word */ | |
uptr->WRITTEN = TRUE; | |
if (ba >= uptr->hwmark) | |
uptr->hwmark = ba + 1; | |
if (M[DT_WC] == 0) | |
dt_substate = DTO_WCO; | |
if (wrd != (dir? 0: DTU_BSIZE (uptr) - 1)) /* not last? */ | |
sim_activate (uptr, DT_WSIZE * dt_ltime); | |
else { | |
dt_substate = dt_substate | DTO_SOB; | |
sim_activate (uptr, ((2 * DT_HTLIN) + DT_WSIZE) * dt_ltime); | |
if (((dtsa & DTA_MODE) == 0) || (M[DT_WC] == 0)) | |
dtsb = dtsb | DTB_DTF; /* set DTF */ | |
} | |
break; | |
case DTO_WCO | DTO_SOB: /* all done */ | |
dt_schedez (uptr, dir); /* sched end zone */ | |
break; | |
} /* end case subst */ | |
break; | |
/* Read all has two subcases | |
Not word count overflow - increment MA, WC, copy word from tape to memory | |
Word count overflow - schedule end zone | |
*/ | |
case FNC_RALL: /* read all */ | |
switch (dt_substate) { /* case on substate */ | |
case 0: case DTO_SOB: /* read in progress */ | |
if (dtsb & DTB_DTF) { /* DTF set? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
return SCPE_OK; | |
} | |
relpos = DT_LIN2OF (uptr->pos, uptr); /* cur pos in blk */ | |
M[DT_WC] = (M[DT_WC] + 1) & DMASK; /* incr WC, CA */ | |
M[DT_CA] = (M[DT_CA] + 1) & DMASK; | |
ma = M[DT_CA] & AMASK; /* mem addr */ | |
if ((relpos >= DT_HTLIN) && /* in data zone? */ | |
(relpos < (DTU_LPERB (uptr) - DT_HTLIN))) { | |
wrd = DT_LIN2WD (uptr->pos, uptr); | |
ba = (blk * DTU_BSIZE (uptr)) + wrd; | |
dtdb = fbuf[ba]; /* get tape word */ | |
} | |
else dtdb = dt_gethdr (uptr, blk, relpos); /* get hdr */ | |
if (dir) /* rev? comp obv */ | |
dtdb = dt_comobv (dtdb); | |
sim_activate (uptr, DT_WSIZE * dt_ltime); | |
if (MEM_ADDR_OK (ma)) /* mem addr legal? */ | |
M[ma] = dtdb; | |
if (M[DT_WC] == 0) | |
dt_substate = DTO_WCO; | |
if (((dtsa & DTA_MODE) == 0) || (M[DT_WC] == 0)) | |
dtsb = dtsb | DTB_DTF; /* set DTF */ | |
break; | |
case DTO_WCO: case DTO_WCO | DTO_SOB: /* all done */ | |
dt_schedez (uptr, dir); /* sched end zone */ | |
break; | |
} /* end case substate */ | |
break; | |
/* Write all has two subcases | |
Not word count overflow - increment MA, WC, copy word from memory to tape | |
Word count overflow - schedule end zone | |
*/ | |
case FNC_WALL: /* write all */ | |
switch (dt_substate) { /* case on substate */ | |
case 0: case DTO_SOB: /* read in progress */ | |
if (dtsb & DTB_DTF) { /* DTF set? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
return SCPE_OK; | |
} | |
relpos = DT_LIN2OF (uptr->pos, uptr); /* cur pos in blk */ | |
M[DT_WC] = (M[DT_WC] + 1) & DMASK; /* incr WC, CA */ | |
M[DT_CA] = (M[DT_CA] + 1) & DMASK; | |
ma = M[DT_CA] & AMASK; /* mem addr */ | |
if ((relpos >= DT_HTLIN) && /* in data zone? */ | |
(relpos < (DTU_LPERB (uptr) - DT_HTLIN))) { | |
dtdb = M[ma]; /* get mem word */ | |
if (dir) | |
dtdb = dt_comobv (dtdb); | |
wrd = DT_LIN2WD (uptr->pos, uptr); | |
ba = (blk * DTU_BSIZE (uptr)) + wrd; | |
fbuf[ba] = dtdb; /* write word */ | |
if (ba >= uptr->hwmark) | |
uptr->hwmark = ba + 1; | |
} | |
/* ignore hdr */ | |
sim_activate (uptr, DT_WSIZE * dt_ltime); | |
if (M[DT_WC] == 0) | |
dt_substate = DTO_WCO; | |
if (((dtsa & DTA_MODE) == 0) || (M[DT_WC] == 0)) | |
dtsb = dtsb | DTB_DTF; /* set DTF */ | |
break; | |
case DTO_WCO: case DTO_WCO | DTO_SOB: /* all done */ | |
dt_schedez (uptr, dir); /* sched end zone */ | |
break; | |
} /* end case substate */ | |
break; | |
/* Type 550 service */ | |
/* Search */ | |
#else /* Type 550 */ | |
case FNC_SRCH: /* search */ | |
if (dtsb & DTB_DTF) { /* DTF set? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
return SCPE_OK; | |
} | |
sim_activate (uptr, DTU_LPERB (uptr) * dt_ltime);/* sched next block */ | |
dtdb = blk; /* store block # */ | |
dtsb = dtsb | DTB_DTF; /* set DTF */ | |
if (DEBUG_PRI (dt_dev, LOG_MS)) | |
fprintf (sim_deb, ">>DT%d: search found block %d\n", unum, blk); | |
break; | |
/* Read and read all */ | |
case FNC_READ: case FNC_RALL: | |
if (dtsb & DTB_DTF) { /* DTF set? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
return SCPE_OK; | |
} | |
sim_activate (uptr, DT_WSIZE * dt_ltime); /* sched next word */ | |
relpos = DT_LIN2OF (uptr->pos, uptr); /* cur pos in blk */ | |
if ((relpos >= DT_HTLIN) && /* in data zone? */ | |
(relpos < (DTU_LPERB (uptr) - DT_HTLIN))) { | |
wrd = DT_LIN2WD (uptr->pos, uptr); | |
ba = (blk * DTU_BSIZE (uptr)) + wrd; | |
dtdb = fbuf[ba]; /* get tape word */ | |
dtsb = dtsb | DTB_DTF; /* set flag */ | |
} | |
else { | |
ma = (2 * DT_HTWRD) + DTU_BSIZE (uptr) - DT_CSMWD - 1; | |
wrd = relpos / DT_WSIZE; /* hdr start = wd 0 */ | |
#if defined (OLD_TYPE550) | |
if ((wrd == 0) || /* skip 1st, last */ | |
(wrd == ((2 * DT_HTWRD) + DTU_BSIZE (uptr) - 1))) break; | |
#endif | |
if ((fnc == FNC_READ) && /* read, skip if not */ | |
(wrd != DT_CSMWD) && /* fwd, rev cksum */ | |
(wrd != ma)) | |
break; | |
dtdb = dt_gethdr (uptr, blk, relpos); | |
if (wrd == (dir? DT_CSMWD: ma)) /* at end csum? */ | |
dtsb = dtsb | DTB_BEF; /* end block */ | |
else dtsb = dtsb | DTB_DTF; /* else next word */ | |
} | |
if (dir) | |
dtdb = dt_comobv (dtdb); | |
break; | |
/* Write and write all */ | |
case FNC_WRIT: case FNC_WALL: | |
if (dtsb & DTB_DTF) { /* DTF set? */ | |
dt_seterr (uptr, DTB_TIM); /* timing error */ | |
return SCPE_OK; | |
} | |
sim_activate (uptr, DT_WSIZE * dt_ltime); /* sched next word */ | |
relpos = DT_LIN2OF (uptr->pos, uptr); /* cur pos in blk */ | |
if ((relpos >= DT_HTLIN) && /* in data zone? */ | |
(relpos < (DTU_LPERB (uptr) - DT_HTLIN))) { | |
wrd = DT_LIN2WD (uptr->pos, uptr); | |
ba = (blk * DTU_BSIZE (uptr)) + wrd; | |
if (dir) /* get data word */ | |
fbuf[ba] = dt_comobv (dtdb); | |
else fbuf[ba] = dtdb; | |
if (ba >= uptr->hwmark) | |
uptr->hwmark = ba + 1; | |
if (wrd == (dir? 0: DTU_BSIZE (uptr) - 1)) | |
dtsb = dtsb | DTB_BEF; /* end block */ | |
else dtsb = dtsb | DTB_DTF; /* else next word */ | |
} | |
else { | |
wrd = relpos / DT_WSIZE; /* hdr start = wd 0 */ | |
#if defined (OLD_TYPE550) | |
if ((wrd == 0) || /* skip 1st, last */ | |
(wrd == ((2 * DT_HTWRD) + DTU_BSIZE (uptr) - 1))) break; | |
#endif | |
if ((fnc == FNC_WRIT) && /* wr, skip if !csm */ | |
(wrd != ((2 * DT_HTWRD) + DTU_BSIZE (uptr) - DT_CSMWD - 1))) | |
break; | |
dtsb = dtsb | DTB_DTF; /* set flag */ | |
} | |
break; | |
#endif | |
default: | |
dt_seterr (uptr, DTB_SEL); /* impossible state */ | |
break; | |
} /* end case function */ | |
DT_UPDINT; /* update interrupts */ | |
return SCPE_OK; | |
} | |
/* Utility routines */ | |
/* Set error flag */ | |
void dt_seterr (UNIT *uptr, int32 e) | |
{ | |
int32 mot = DTS_GETMOT (uptr->STATE); | |
dtsa = dtsa & ~DTA_STSTP; /* clear go */ | |
dtsb = dtsb | DTB_ERF | e; /* set error flag */ | |
if (mot >= DTS_ACCF) { /* ~stopped or stopping? */ | |
sim_cancel (uptr); /* cancel activity */ | |
if (dt_setpos (uptr)) /* update position */ | |
return; | |
sim_activate (uptr, dt_dctime); /* sched decel */ | |
DTS_SETSTA (DTS_DECF | (mot & DTS_DIR), 0); /* state = decel */ | |
} | |
DT_UPDINT; | |
return; | |
} | |
/* Schedule end zone */ | |
void dt_schedez (UNIT *uptr, int32 dir) | |
{ | |
int32 newpos; | |
if (dir) /* rev? rev ez */ | |
newpos = DT_EZLIN - DT_WSIZE; | |
else newpos = DTU_FWDEZ (uptr) + DT_WSIZE; /* fwd? fwd ez */ | |
sim_activate (uptr, ABS (newpos - ((int32) uptr->pos)) * dt_ltime); | |
return; | |
} | |
/* Complement obverse routine */ | |
int32 dt_comobv (int32 dat) | |
{ | |
dat = dat ^ DMASK; /* compl obverse */ | |
dat = ((dat >> 15) & 07) | ((dat >> 9) & 070) | | |
((dat >> 3) & 0700) | ((dat & 0700) << 3) | | |
((dat & 070) << 9) | ((dat & 07) << 15); | |
return dat; | |
} | |
/* Checksum routine */ | |
int32 dt_csum (UNIT *uptr, int32 blk) | |
{ | |
int32 *fbuf = (int32 *) uptr->filebuf; | |
int32 ba = blk * DTU_BSIZE (uptr); | |
int32 i, csum, wrd; | |
#if defined (TC02) /* TC02/TC15 */ | |
csum = 077; /* init csum */ | |
for (i = 0; i < DTU_BSIZE (uptr); i++) { /* loop thru buf */ | |
wrd = fbuf[ba + i] ^ DMASK; /* get ~word */ | |
csum = csum ^ (wrd >> 12) ^ (wrd >> 6) ^ wrd; | |
} | |
return (csum & 077); | |
#else /* Type 550 */ | |
csum = 0777777; | |
for (i = 0; i < DTU_BSIZE (uptr); i++) { /* loop thru buf */ | |
wrd = fbuf[ba + i]; /* get word */ | |
csum = csum + wrd; /* 1's comp add */ | |
if (csum > DMASK) | |
csum = (csum + 1) & DMASK; | |
} | |
return (csum ^ DMASK); /* 1's comp res */ | |
#endif | |
} | |
/* Get header word */ | |
int32 dt_gethdr (UNIT *uptr, int32 blk, int32 relpos) | |
{ | |
int32 wrd = relpos / DT_WSIZE; | |
if (wrd == DT_BLKWD) /* fwd blknum */ | |
return blk; | |
#if defined (TC02) /* TC02/TC15 */ | |
if (wrd == DT_CSMWD) /* rev csum */ | |
return 077; | |
if (wrd == ((2 * DT_HTWRD) + DTU_BSIZE (uptr) - DT_CSMWD - 1)) /* fwd csum */ | |
return (dt_csum (uptr, blk) << 12); | |
#else /* Type 550 */ | |
if (wrd == DT_CSMWD) /* rev csum */ | |
return 0777777; | |
if (wrd == ((2 * DT_HTWRD) + DTU_BSIZE (uptr) - DT_CSMWD - 1)) /* fwd csum */ | |
return (dt_csum (uptr, blk)); | |
#endif | |
if (wrd == ((2 * DT_HTWRD) + DTU_BSIZE (uptr) - DT_BLKWD - 1)) /* rev blkno */ | |
return dt_comobv (blk); | |
return 0; /* all others */ | |
} | |
/* Reset routine */ | |
t_stat dt_reset (DEVICE *dptr) | |
{ | |
int32 i, prev_mot; | |
UNIT *uptr; | |
for (i = 0; i < DT_NUMDR; i++) { /* stop all drives */ | |
uptr = dt_dev.units + i; | |
if (sim_is_running) { /* CAF? */ | |
prev_mot = DTS_GETMOT (uptr->STATE); /* get motion */ | |
if ((prev_mot & ~DTS_DIR) > DTS_DECF) { /* accel or spd? */ | |
if (dt_setpos (uptr)) /* update pos */ | |
continue; | |
sim_cancel (uptr); | |
sim_activate (uptr, dt_dctime); /* sched decel */ | |
DTS_SETSTA (DTS_DECF | (prev_mot & DTS_DIR), 0); | |
} | |
} | |
else { | |
sim_cancel (uptr); /* sim reset */ | |
uptr->STATE = 0; | |
uptr->LASTT = sim_grtime (); | |
} | |
} | |
dtsa = dtsb = 0; /* clear status */ | |
DT_UPDINT; /* reset interrupt */ | |
return SCPE_OK; | |
} | |
/* IORS routine */ | |
int32 dt_iors (void) | |
{ | |
#if defined IOS_DTA | |
return ((dtsb & (DTB_ERF | DTB_DTF))? IOS_DTA: 0); | |
#else | |
return 0; | |
#endif | |
} | |
/* Attach routine | |
Determine 12b, 16b, or 18b/36b format | |
Allocate buffer | |
If 12b, read 12b format and convert to 18b in buffer | |
If 16b, read 16b format and convert to 18b in buffer | |
If 18b/36b, read data into buffer | |
*/ | |
t_stat dt_attach (UNIT *uptr, char *cptr) | |
{ | |
uint16 pdp8b[D8_NBSIZE]; | |
uint16 pdp11b[D18_BSIZE]; | |
uint32 ba, sz, k, *fbuf; | |
int32 u = uptr - dt_dev.units; | |
t_stat r; | |
r = attach_unit (uptr, cptr); /* attach */ | |
if (r != SCPE_OK) /* error? */ | |
return r; | |
if ((sim_switches & SIM_SW_REST) == 0) { /* not from rest? */ | |
uptr->flags = uptr->flags & ~(UNIT_8FMT | UNIT_11FMT); /* default 18b */ | |
if (sim_switches & SWMASK ('T')) /* att 12b? */ | |
uptr->flags = uptr->flags | UNIT_8FMT; | |
else if (sim_switches & SWMASK ('S')) /* att 16b? */ | |
uptr->flags = uptr->flags | UNIT_11FMT; | |
else if (!(sim_switches & SWMASK ('A')) && /* autosize? */ | |
(sz = sim_fsize (uptr->fileref))) { | |
if (sz == D8_FILSIZ) | |
uptr->flags = uptr->flags | UNIT_8FMT; | |
else if (sz == D11_FILSIZ) | |
uptr->flags = uptr->flags | UNIT_11FMT; | |
} | |
} | |
uptr->capac = DTU_CAPAC (uptr); /* set capacity */ | |
uptr->filebuf = calloc (uptr->capac, sizeof (uint32)); | |
if (uptr->filebuf == NULL) { /* can't alloc? */ | |
detach_unit (uptr); | |
return SCPE_MEM; | |
} | |
fbuf = (uint32 *) uptr->filebuf; /* file buffer */ | |
printf ("%s%d: ", sim_dname (&dt_dev), u); | |
if (uptr->flags & UNIT_8FMT) | |
printf ("12b format"); | |
else if (uptr->flags & UNIT_11FMT) | |
printf ("16b format"); | |
else printf ("18b/36b format"); | |
printf (", buffering file in memory\n"); | |
if (uptr->flags & UNIT_8FMT) { /* 12b? */ | |
for (ba = 0; ba < uptr->capac; ) { /* loop thru file */ | |
k = fxread (pdp8b, sizeof (uint16), D8_NBSIZE, uptr->fileref); | |
if (k == 0) | |
break; | |
for ( ; k < D8_NBSIZE; k++) | |
pdp8b[k] = 0; | |
for (k = 0; k < D8_NBSIZE; k = k + 3) { /* loop thru blk */ | |
fbuf[ba] = ((uint32) (pdp8b[k] & 07777) << 6) | | |
((uint32) (pdp8b[k + 1] >> 6) & 077); | |
fbuf[ba + 1] = ((uint32) (pdp8b[k + 1] & 077) << 12) | | |
((uint32) pdp8b[k + 2] & 07777); | |
ba = ba + 2; /* end blk loop */ | |
} | |
} /* end file loop */ | |
uptr->hwmark = ba; | |
} /* end if */ | |
else if (uptr->flags & UNIT_11FMT) { /* 16b? */ | |
for (ba = 0; ba < uptr->capac; ) { /* loop thru file */ | |
k = fxread (pdp11b, sizeof (uint16), D18_BSIZE, uptr->fileref); | |
if (k == 0) | |
break; | |
for ( ; k < D18_BSIZE; k++) | |
pdp11b[k] = 0; | |
for (k = 0; k < D18_BSIZE; k++) | |
fbuf[ba++] = pdp11b[k]; | |
} | |
uptr->hwmark = ba; | |
} /* end elif */ | |
else uptr->hwmark = fxread (uptr->filebuf, sizeof (uint32), | |
uptr->capac, uptr->fileref); | |
uptr->flags = uptr->flags | UNIT_BUF; /* set buf flag */ | |
uptr->pos = DT_EZLIN; /* beyond leader */ | |
uptr->LASTT = sim_grtime (); /* last pos update */ | |
return SCPE_OK; | |
} | |
/* Detach routine | |
Cancel in progress operation | |
If 12b, convert 18b buffer to 12b and write to file | |
If 16b, convert 18b buffer to 16b and write to file | |
If 18b/36b, write buffer to file | |
Deallocate buffer | |
*/ | |
void dt_flush (UNIT* uptr) | |
{ | |
uint16 pdp8b[D8_NBSIZE]; | |
uint16 pdp11b[D18_BSIZE]; | |
int32 k; | |
uint32 ba, *fbuf; | |
if (uptr->WRITTEN && uptr->hwmark && ((uptr->flags & UNIT_RO)== 0)) { /* any data? */ | |
rewind (uptr->fileref); /* start of file */ | |
fbuf = (uint32 *) uptr->filebuf; /* file buffer */ | |
if (uptr->flags & UNIT_8FMT) { /* 12b? */ | |
for (ba = 0; ba < uptr->hwmark; ) { /* loop thru file */ | |
for (k = 0; k < D8_NBSIZE; k = k + 3) { /* loop blk */ | |
pdp8b[k] = (fbuf[ba] >> 6) & 07777; | |
pdp8b[k + 1] = ((fbuf[ba] & 077) << 6) | | |
((fbuf[ba + 1] >> 12) & 077); | |
pdp8b[k + 2] = fbuf[ba + 1] & 07777; | |
ba = ba + 2; | |
} /* end loop blk */ | |
fxwrite (pdp8b, sizeof (uint16), D8_NBSIZE, uptr->fileref); | |
if (ferror (uptr->fileref)) | |
break; | |
} /* end loop file */ | |
} /* end if 12b */ | |
else | |
if (uptr->flags & UNIT_11FMT) { /* 16b? */ | |
for (ba = 0; ba < uptr->hwmark; ) { /* loop thru file */ | |
for (k = 0; k < D18_BSIZE; k++) /* loop blk */ | |
pdp11b[k] = fbuf[ba++] & 0177777; | |
fxwrite (pdp11b, sizeof (uint16), D18_BSIZE, uptr->fileref); | |
if (ferror (uptr->fileref)) | |
break; | |
} /* end loop file */ | |
} /* end if 16b */ | |
else | |
fxwrite (uptr->filebuf, sizeof (uint32), /* write file */ | |
uptr->hwmark, uptr->fileref); | |
if (ferror (uptr->fileref)) | |
perror ("I/O error"); | |
} | |
uptr->WRITTEN = FALSE; /* no longer dirty */ | |
} | |
t_stat dt_detach (UNIT* uptr) | |
{ | |
int32 u = uptr - dt_dev.units; | |
if (!(uptr->flags & UNIT_ATT)) | |
return SCPE_OK; | |
if (sim_is_active (uptr)) { | |
sim_cancel (uptr); | |
if ((u == DTA_GETUNIT (dtsa)) && (dtsa & DTA_STSTP)) { | |
dtsb = dtsb | DTB_ERF | DTB_SEL | DTB_DTF; | |
DT_UPDINT; | |
} | |
uptr->STATE = uptr->pos = 0; | |
} | |
if (uptr->hwmark && ((uptr->flags & UNIT_RO) == 0)) { /* any data? */ | |
printf ("%s%d: writing buffer to file\n", sim_dname (&dt_dev), u); | |
dt_flush (uptr); | |
} /* end if hwmark */ | |
free (uptr->filebuf); /* release buf */ | |
uptr->flags = uptr->flags & ~UNIT_BUF; /* clear buf flag */ | |
uptr->filebuf = NULL; /* clear buf ptr */ | |
uptr->flags = uptr->flags & ~(UNIT_8FMT | UNIT_11FMT); /* default fmt */ | |
uptr->capac = DT_CAPAC; /* default size */ | |
return detach_unit (uptr); | |
} |