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Preamble
If you have questions, please do Not first email the author,
instead join the mail
list, then mail that list and the author.
I owned two of the last surviving Symmetric 375s (one went
to "Bernd Kopriva" <bernd @ Kopriva _ERASE_
.de> Nov. 2003, & 2nd one too,
2006.05.10) (He also has what was my PC532.)
Occasionally people discover spare machines, & want to
rebuild them, so I'm putting virtually all info on the net,
including distribution tape & other binaries such as gcc
& gdb, + scs reconfigurable kernel kit etc. If you
discover one of these extremely rare boxes, don't throw it
out - you can now reinstall it instead.
My FTP Archive: ftp://ftp.berklix.com/pub/symmetric/
I stopped merging & reducing & re ordering it around
2006.05.11 there's still duplication of some components.
Several index files exist there in capital letter names.
Somebody else is welcome to use tools like find & md5
& my own cmpd
to further reduce it please.
Symmetric mail list
Index Within This Page
Index Of Extra Files & Directories
- via ftp: docs/ Scanned paper
manual
- docs/: Adverts & Floppy
power
- 4.2 Tape jhs
bits: makefile & notes
- 4.2 Tape: SCS
files on tape - to write a tape or install
operating system on salvaged/ recovered/ found hardware
- 4.3 Tape:
- via ftp: scs: boot.flp How to rebuild
from floppy and tape
- jhs:
disc_labels.txt
- via ftp: scs: qa/ - Quality Assurance
scripts
- jhs: letters/
- jhs: history
- Pictures
Here's a modified copy of an /etc/motd I once had:
S Y M M E T R I C 3 7 5
Hardware: Symmetric 375, Processor NSC 32016, 11.0592 MHz, 2Mbyte RAM,
WD1002-05 + 1-3 ST506 ~75M Discs, 4 x Serial, Ethernet, 1 Parallel,
3.5 & 5.25" Flop.
Timezone Kernel: PDT=GMT-7. Not year 2000 compliant clock,
so rdist will fail in direction this host to modern host.
make:
28672 /bin/make
29696 /usr/bin/local/make
105472 /usr/gnu/bin/make
/usr2/local/include/make: bsd msdos system_5 unix
/usr2/local/make: make.c makefile
Coms Program Binaries:
/usr/local/kermit works ok (to guug)
If Symmetric/modem link is at 38400, transfers fail, 9600 is OK.
/usr/bin/local/kermit-5a has been compiled, but not tested.
/usr/bin/local/sz works ok (to pc532)
/usr/bin/local/xmodem untested
gnu/taylor uucp & ftp binaries (slip included) exist.
SCS Binaries: C,Pascal,2 Basics,F77,APL,Lisp,Prolog,Ingres,Gdb,Emacs,Kermit.
By SCS CC: /usr/src/local/*. Little Smalltalk 3.04. Zmodem (sz,rz),
Egrep, Gas, Gas-1.38.1, Gdb-3.5, Grep, Install, Tar, Texi2index,
Texi2roff Objdump, Patch-2.0.12u4.
By GCC: Bash-1.05, Bash-1.12, Bison-1.11, Cpio-1.4, Fileutils-1.4,
Find-2.2, GCC-1.40, Ghostscript-2.3, Make-3.60, Zoo-2.1.
Kermit-5a, gzip-1.2.2, vile
In gnu/bin: cat chmod cmp cp cut d dd dir du egrep gsnd head install ln ls
mkdir mkfifo mt mv objdump paste rm rmdir tac tail touch v vdir
Timezone: PDT - (as reconfigurable kit to permit MET has bad tape driver).
- NSC 32016 11.0592 MHz.
- 2M RAM, soldered, not socketed, no expansion
room.
- Discs: Seperate 5.25" form factor controller card
with WD1002-05 for 3 ST506 Discs. 1 standard 5.25" internal
disc, + SCS chassis socket for 2nd disc. I jhs extended both
chassis for 3rd (2nd external) disc. (my internals are 135 M
(1024 bytes/sector, 9 sectors/track, 15 tracks/cylinder, 1024
cylinders) & 80 M, externals are 75M),
- 4 Serial, (top clock speed 38400 is limited pair
wise, ie no 38400 on tty0 & 19200 on tty1), supports
SLIP.
- 1 Parallel Switchable (ie you can select the
strobe polarity) Centronics or .....
- Floppy external socket supports 2 floppy drives,
5.25" or 3.5", 720k (9 * 512 * 80 * 2) or 800k ( 5 * 1024 *
80 * 2 ) (& none of that evil PC slit & twisted
ribbon stuff!)
- Ethernet: 1 with (AUI), 1 without. I used this
with an AUI to thin co-ax transceiver, IEEE 802.3 10Base2
Manufacturer Lantronix, Model LTX-2, Switch setting: HBE=On,
Rcv=On, this allowed transmission at 50 K Bytes/sec to a
faster receiving machine. Without RCV turned on rlogin still
worked, but FTP locked up after 2K. When I used CentreCOM 210
Twisted pair transceivers, IEEE 802/3 10Base T (MAU), they
only had an SQ (Heartbeat) switch, rlogin & ftp
transmission worked with that turned off. In both cases en0
was ifconf'ed by the /etc/rc* stuff with with "-trailers" I
believe
- Tape Drive: SCSI Cassette (not cartridge), 60M
drive, SCS driver uses it as 50M). SCSI external
connector.
works in single user mode, drops occasional single bytes
multi user, to recover tape data, see slice.c
-
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CONTENTS OF SYMMETRICS by JHS (interesting bits only, no boring glue logic)
&& Means same on both Symmetrics.
&& PCB Rev 32 S375
Both have same single patch on board reverse side:
DR Pin 3 to near a big hole.
My 33c95 is socketed, Chucks isn't.
The 2 adjacent DIP headers appear to be for 19200/38400 baud rate switching.
Open = 38400, Connected=19200,
presumably 1 DIP for /dev/console & tty1, other for tty2 & tty3.
AS WRITTEN ON COMPONENTS. MY NOTES
&& NS32016D-10 R S8640 CPU
NS32082D-10 N (S8632,S8636=Chuck) MMU
&& NS32201D-10 SS8620 TCU
NS32081D-10 F (S8652,S8632=Chuck) FPU
| | | ^^^^ Year and month (more likely year & week).
| | ^ Flow code (ie which production line & factory).
| ^^ MHz
^ D means ceramic
&& CrystalA 22.11840 MHz MP221 CTS JAPAN
&& RAM 4 * 16 * KM41256-15 6382 koreaA No Sockets, No room for more.
&& Eproms Type 2732, 1 even & 1 odd P/N B8 & B9 Rev 1.11
SCN2681A, Signetics (2 * K8701=jhs,K8449 & K8621=Chuck) C1N40 E RS 232
WD 33C93-PL 00-02 8648 PROTO C.WDC'85(socketed) SCSI bus adapter module
R6522AP R6522-33 8438 (Rockwell?) Parallel Port
MMI PAL 20L10CNS 652120
NEC D4016C-2 8634B9206 <-- is this also on scs board, or just on the wd board?
--------------------------------------------------------------------------------
Ethernet (SCS) Board:
Silk Screen Name: SCS ENET REV2 COPYR 1986 WFJ/lgj
Crystal 20.008643 MHz
AM7990DC 60 8541GP C. '84 AMD
AM 7992 BDC 8618 DP
--------------------------------------------------------------------------------
Western Digital Controller Board 1002-05 (40 pin ribbon to cpu)
Assy 61-031094-00 (only uses +5V )
WD1014-CL 00-02 8635 C. WDC '82 ECC Buffer Controller
WD1010A-PL 05-05 8640 C. WDC '82 Winchester Controller
WD2797A-PL 02-04 8609 C. WDC '82 (socketed) Floppy Controller
WD 62-002010-010 (socketed)
NEC D4016-2
--------------------------------------------------------------------------------
Power ONE DC Power Supplies Observed by JHS
80W written on PCB
PIN DESCRIPTION
1 Live
2 neutral
3 Ground
4 -12 0.6A
5 +12 1.2 A
6 +12 2.5 A / 5 Pk Orange Wire
7 Common
8 +5V 8A
Max IP 125 W AC Cont, OP 80W DC Cont
--------------------------------------------------------------------------------
Streamer Cassette Tape Drive: TEAC MT-2ST/45S-24-U
Herr Heiber of nbn confirmed it is a 60M drive 901106
even though SCS driver only use 50M.
he sent me a manual.
Serial 714550, FCC ID:DX983C
Head Assembly: TEAC 14769360-00 7819 C, Seiko Epson Corp.
Motor on front spindle (source) teac 14733870-50 dm-4500b No 19x7b
Motor on back spindle (take up) teac 14733870-00 dm-4500a No 09x7c
--------------------------------------------------------------------------------
Winchester: Miniscribe model 6085 p/n 040006092C-077 Serial 117222
Information for Model 6085 from Western Digital via pc bulletin boards:
Phone: +1 303 651 6000
Type: ST-506 MFM
Size: 5.25" Full height form factor
Capacity: 71 Mbyte (formatted)
Cylinders: 1024
Data Heads: 8
Start Reduced Write Current: 1025
Start Write Precomp: 512
Encoding Method: MFM (Modified Frequency. Modulation)
Transfer Rate: 5 MEGABITS/SEC
Average Access Time: 28 MS
Sectors/Track X 512 bytes: 17
Information from SCS disktab entry:
miniscribe85|Miniscribe 6085 85Mb:\
:ty=st506: Type of disk (e.g. st506, floppy)
:se#1024: Sector size in bytes
:nt#8: Number of tracks per cylinder
:ns#9: Number of sectors per track
:nc#1024: Total number of cylinders on the disk
JHS NOTE Capacity multiplies to 75497472 = 72M
(M=1024^2). There was no :wp#512: entry found
(Write pre-compensation cyl. (ST506 only)).
--------------------------------------------------------
JHS Note 136 cylinders Root
:pa#9792: Size of partition `a' in sectors
:oa#0: Offset of partition `a' in cylinders
--------------------------------------------------------
JHS Note 60 cylinders Paging
:pb#4320: Size of partition `b' in sectors
:ob#136: Offset of partition `b' in cylinders
--------------------------------------------------------
JHS Note 1024 cylinders, Pack
copying (inc. bad sector replacement)
:pc#73728: Size of partition `c' in sectors
:oc#0: Offset of partition `c' in cylinders
--------------------------------------------------------
:pd#0:od#0:pe#0:oe#0:pf#0:of#0:pg#0:og#0:
--------------------------------------------------------
JHS Note 825 cylinders /usr
:ph#59400: Size of partition `h' in sectors
:oh#196: Offset of partition `h' in cylinders
Information visually observable on drive:
12v 1.8a 5v 0.9A Total flaws 53 Surface 4 has 18 flaws.
CYL HD OFFSET
283 0 4288
26 1 9120
37 1 176
38 1 176
49 2 9584
50 2 9584
130 2 2592
198 2 6944
200 2 4576
201 2 4576
215 2 864
215 2 5904
229 2 8941
282 2 10032
389 2 4144
440 2 8672
441 2 8496
589 2 5104
932 2 1296
999 2 240
486 3 4672
506 3 8352
779 3 9648
847 3 4288
80 4 208
115 4 9184
130 4 9424
151 4 1923
199 4 2864
227 4 2304
235 4 3040
254 4 3104
352 4 8720
359 4 2022
401 4 7552
451 4 2512
471 4 8144
485 4 8704
486 4 8704
813 4 9333
813 4 9568
814 4 9568
170 5 8272
286 6 3312
294 6 7968
389 6 2784
419 6 2054
419 6 2144
420 6 2054
420 6 2128
421 6 2054
421 6 2144
436 6 6544
end of list
Notes on biker (host from chuck) pals (seen with eproms above pals):
EPROMS
H3 H4
H1 H2
H3 H4
PAL 20R4ACNS PAL20L8ACNS
8642 8626
MMI
H1 H2
PAL 20R6ACNS PAL20R6ACNS
706296 706296
MMI
rs232 From Manual: Serials are configured like
DCEs (Modems). Internally DCD 8 is wired to DSR 6. Console DCD
is wired active. Available: 2 TXD In, 3 RXD Out, 4 RTS In, 5
CTS Out, 6 DSR Out, 8 DCD Out, 20 DTR In.
Kermit Observed: When started, & connected just to led
box, raises 5,6,8
I noticed lowered performance when hanging on a long 30 to
50 metre serial cable which sometimes didn't have a laptop
connected at far end: ps then showed gettys with random noise
as login name, simple solution was to put a terminating plug on
far end of serial cable when not connected to a laptop. This
leads to question of if Symmetric used a cheap 7400 series 5V
chip, or a more expensive 12 differential chip ? I don't
know.
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DEVICE NAMES MENTIONED WHEN BOOTING:
en is ether
wd is winch drive
sb = scsi
cst is cassette tape
cpu is scsi address 1
cst 2 is scsi address 2
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CONTENTS OF /usr/include/sys/reboot.h
/* * @(#)reboot.h 3.1 7/29/84
* @(#)Copyright (C) 1984 by National Semiconductor Corp. */
/* * Arguments to reboot system call.
* These are passed to boot program in r11,
* and on to init. */
#define RB_AUTOBOOT 0 /* flags for system auto-booting itself */
#define RB_ASKNAME 0x01 /* ask for file name to reboot from */
#define RB_SINGLE 0x02 /* reboot to single user only */
#define RB_NOSYNC 0x04 /* don't sync before reboot */
#define RB_HALT 0x08 /* don't reboot, just halt */
#define RB_INITNAME 0x10 /* name given for /etc/init */
#define RB_DFLTROOT 0x20 /* don't use bootdev for rootdev */
#define RB_PANIC 0 /* reboot due to panic */
#define RB_BOOT 1 /* reboot due to boot() */
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BOOTING SYNTAX
Stop unix (& sync discs)
halt
Boot from ?
b0
Load /boot resulting in prompt Boot:
b1
Boot multi user :
b or b 0
Boot /vmunix single user:
b2
Single to Multi user
^D
Load boot from winchester, resulting in Boot: prompt
b3 or b 3 or b 3 0
Stand alone formatter from Boot:
wd0a:/stand/format
wd0h: would access usr partition
fd0 probably would access floppy disc
cst2f To format winchester
Boot from cst2b:
(wd0a:/boot was unusable (copied from miniroot))
(unfortunately this boot doesn't recognise fd0: addresses,
wdstrategy complains I/O out of filesystem boundaries)
b3 1 2
Boot Single User From Floppy (manual page 104) - this does not read
wd0a:/boot, but instead reads wd3a:/boot (the floppy boot)
b2 0 3
Boot From Tape
b3 1 2
Boot From Winchester Swap Partition (after installing miniroot in swap
partition with initroot program
b3
wd0b:vmunix
Tape Capacity
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My drive is a TEAC MT-2ST/45S-24-U:w
Maxell CS 600HD
I think the Maxell CS600HX are 150M tapes.
Tapes considered by Inmac & Seemuller to be 60M,
But Symmetric considers them 50M, whether `testblock' blocking set to
4k or 20k, Presumably what would stand a better chance of changing
the capacity is to change the block size in the driver.
Seemuller Oct 1990
49DM 1 off
40DM 10 off
SOLUTIONS Ltd +44 959 61204 May 90
1 box of 10 @ 5% discount
150 off price retail at #170 with 30% discount
nbn Elektronik GmbH, April 90
Herr Kulartz, Gewerbegebeit, Herrsching. +49 8152 1017
50M 1 cassette @ 45 DM
60M 1 cassette @ 55 DM
60M 10 cassettes @ 38 DM
60M 50 cassettes @ 33 DM
all + mwst + 1% + post (post=10dm for 10)
SCS Inc (Defunct)
$22.5 tapes found to be 40M
- - - - - - - - - -
Power To Main board
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Top Of Page
power converter, standard pc to symmetric
( as made ~910918, dismantled 9301 )
standard pc symmetric
1 + 5 --+ 0 1 black
2 + 5 --+----------+-- + 5 2 red
3 + 5 --+ +-----#-- +12 3 yellow
4 - 5 | | | 0 4 black
5 0 | | +-- + 5 5 red
6 0 | | +----- -12 6 violet
7 0 | | |
8 0 | | |
9 -12 --#----#--+
10 +12 --#----+
11 + 5 --+
12 (+ 5)
power consumptions estimate @ 9301
tape 12v 1.6A max steady (presumably when streaming), more at start.
tape 5v 1 A max steady (presumably when streaming), more at start.
micropolis 5" disc 12 2A average 4.3 @ start.
micropolis 5" disc 5 2A average.
cpu (by observation) 5V 70mA, 12V 50mA, -12V 45mA.
Floppy Wiring
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FLOPPY INTERFACE PIN OUTS
--------------------------------------------------------------------------------
JULIAN'S COMBINED 5.25" + 3.5" FLOPPY DRIVE BOX
(3.5" Chinon drive added to original TEAC 5.25" drive)
TEAC Part No FD-55FV-13-U 19307200-13
Chinon Model No FB357
Originally from Symmetric, usable by Unix & to be tried by Toshiba)
This is the wiring inside the steel box, not the wiring on the external
34 ribbon to 25 D converter (though this can be expected to normally
be the same).
D 25 PIN RIBBON WIRE NUMBER SIGNAL NAME
1 34 Disk Change (Ready)
2 8 Index
3 26 Track 0
4 28 Write Protect Detected
5 30 Read Data
6 4 In Use (External LED)
7 6 Drive Select 3
8 14 Drive Select 2
9 12 Drive Select 1
10 10 Drive Select 0
11 16 Motor On
12 22 Write Data
13 24 Write Gate
14 2 Mode Select (Disk Change)
15 32 Side 1 Select
16 18 Step Direction
17 20 Step Pulse
18-25 GROUND All odd pins (1-33)
TOGGLE SWITCH Alternates Select 0 & 1 lines before presentation
to floppies.
Signals on flop interface are 0=active.
Observation of HD line on Chinon 3.5" drive:
5v= Hi Dens (hole), or No Disc, 0V=720K
Although the 3.25" is a 1.4M drive, the Symmetric cant use it,
because WD controller needs to double frequency.
--------------------------------------------------------------------------------
34 WAY RIBBON CABLE FLOPPY SIGNAL NAMES
Pin In |Chinon 3.5" (jhs) | NEC 3.5" (sja) | NEC 5.25" (sja) | Sym.
Out|FB-357 (135 tpi) | FD1137H | FD1157C | Port
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2 I *Mode Slct *DskChange | Density (Hi=0,Lo=1) | <-- | N/C
4 I In Use LED | N/C | Head Load/In Use | N/C
6 I *Drive Select 3 | Drive Select 3 | <-- | Sel 0
8 O Index | <-- | <-- | <--
10 I Drive Select 0 | <-- | <-- | Sel 1
12 I Drive Select 1 | <-- | <-- | Sel 2
14 I *Drive Select 2 | Drive Select 2 | <-- | Sel 3
16 I Motor On | <-- | <-- | <--
18 I Direction Select (In) | <-- | <-- | <--
20 I Step | <-- | <-- | <--
22 I Write Data | <-- | <-- | <--
24 I Write Gate | <-- | <-- | <--
26 O Track 0 | <-- | <-- | <--
28 O Write Protect Detected | <-- | <-- | <--
30 O Read Data | <-- | <-- | <--
32 I Side Select | <-- | <-- | <--
34 O Disk Change *Ready | Disc Change | Disk Change*Ready | N/C
*Bla means text following asterisk is an option
<-- means same as entry to left. N/C means not connected
Input/output direction is viewed from drive (not computer)
Symmetric pin outs are taken from page 187 of SCS manual
these do not conform to normal select conventions,
Symmetric manual is wrong - probably applies to how floppy port looks
if an internal floppy is fitted.
--------------------------------------------------------------------------------
Toshiba T1100+ FLOPPY PIN OUTS
From: rpw3@ amdcad AMD.COM (Rob Warnock) Systems Architecture Consultant
Date: 7 Jul 87 05:44:43 GMT
UUCP: {amdcad,fortune,sun,attmail}!redwood!rpw3
ATTmail: !rpw3
DDD: (415)572-2607
USPS: 627 26th Ave, San Mateo, CA 94403
Toshiba doesn't document the pin outs on the 25-pin connector
on the back, the one that's shared between the external floppy (can be either
disk "A" or "B") and the parallel printer.
So I engaged in a little electrical
sleuthing, and figured it out the hard way (with the help of a voltmeter and
many LEDs and an oscilloscope). I believe I've succeeded [Minix boots!], and
present the results herein. May it be of some use to someone else.
DISCLAIMER: There are no guarantees that this information is correct,
reliable, or safe. While I am indeed using the connection described in
my own system, I cannot guarantee that it will function in yours, or
that it will not damage your system. There are at least two ambiguous
pairs of signals in the pin outs [which I think don't matter, see below],
and other pins which I show as "unused", even though they appear to have
termination voltages on them. [Anyone having better information as to
the "official" pin outs, please correct me.]
I used a half-height Mitsubishi drive , using a small power pack,
I'm a bit worried that 300ma of +12v might not be enough),
T1100+ DB-25 pin Signal name Floppy edge-connector pin
---------------- ----------- -------------------------
01 Ready 34 [Note#1]
02 Index 08 [Note#1]
03 Track0 26
04 Write-Protect 28
05 Read-Data 30
06-09 (n/u) [Note#3]
10 Select 10 [Note#2]
11 Motor-On 16 [Note#2]
12 Write-Data 22
13 Write-Enable 24
14 (n/u) [Note#3]
15 Head-Select 32
16 Step-Direction 18
17 Step-Pulse 20
18-25 GROUND All odd pins (1-33)
Notes:
#1. It appears that Ready and Index are AND'ed together inside the T1100+
controller, since the disk worked equally well whichever signal was
connected to pins 01 or 02. The assignment given above was chosen
arbitrarily.
#2. It appears that Select and Motor-On are are driven by the same signal
inside the T1100+ controller, since the disk worked equally well whichever
signal was connected to pins 10 or 16, and I did not see any difference
on a 'scope. The assignment given above was chosen arbitrarily.
#3. Pins 6-9 and 14 seem "unused", though they do have +5 "pull ups" on them.
(This may be due to those signals being used when the port is selected
as the parallel printer.)
#4. All signals are "active-low", and are pulled up to +5 by the T1100+ when
inactive.
As I said above, it seems to work fine: MS-DOS "format" works, MS-DOS floppies
can be read and written, and Minix boots and reads /usr.
--------------------------------------------------------------------------------
FLOPPY DISC RIBBON INTERFACE CABLE WITH TWIST As purchased by JHS 9-90.
With 3 sets of [ 3.5" floppy twist connectors + 3 5.25" floppy connector ],
and a twist between one set and the other 2 sets.
First 9 wires are straight through connection,
next 7 are twisted in a group, rest are straight.
1 straight 1
9 straight 9
Select 0 10 twist 16 Motor On
ground 11 twist 15 ground
Select 1 12 twist 14 (Select 2)
ground 13 twist 13 ground
(Select 2) 14 twist 12 Select 1
ground 15 twist 11 ground
Motor On 16 twist 10 Select 0
17 straight 17
34 straight 34
--------------------------------------------------------------------------------
TOSHIBA LAPTOP MANUAL : as read by Joe McBeth (deceased)
(female on floppy & computer)
T1100+ DB-25 PIN TOSH SIGNAL NAME
01 Extern Drive Ready
02 Index
03 Track0
04 Write-Protect
05 Read-Data
06 Disc Change
07-09 Not Used
10 Drive Select 1
11 Motor-On
12 Write-Data
13 Write-Gate
14 Low Density
15 Side 1 Select
16 Step-Direction
17 Step-Pulse
18-25 GROUND
--------------------------------------------------------------------------------
NEC LAPTOP `MULTISPEED' MANUAL DESCRIBING EXTERNAL FDC SOCKET
As read by Julian (15 PIN)
SIGNAL SIGNALBEZEICHNUNG I/O
1 Index Inhaltsverzeichnis 0
2 Motor On C Motoreinschaltung C 1
3 Select D Laufwerkswahl D 1
4 Select C Laufwerkswahl C 1
5 Motor On D Motoreinschaltung D 1
6 Step Direction Laufrichtung 1
7 Step Schrittimpuls 1
8 Write Data Dateneinschreibung 1
9 Write Enable Schreibfreigabe 1
10 Track 0 Spur 0 0
11 Write protect Schreibschutz 0
12 Data Dateileistung 0
13 Head 1 Wahl Schreibkopf 1
14&15 Ground Erde
--------------------------------------------------------------------------------
NOTES ON FLOPPY DRIVERS - By Julian H. Stacey
To accompany valid, dd, symmetric, unix msdos debug scenarios.
The Symmetric Unix device driver source was read, this
reads both head 0 & 1 of track 0, before progressing to track 1.
MSDOS BOOT SECTOR ANALYSIS
From head 0 sector 1 track 0 (note high byte is 2nd byte, ie 0C for
first high byte) Reference: Advanced Msdos by Ray Duncan, page 166.
OFFSET KEY:
- 1 size as reported by chkdsk ("bytes total disc space")
- 2 media size 5.25" / 3.5" as 525 or 350
0B & 0C 3 bytes per sector
0D 4 sectors per cluster
0E & 0F 5 reserved sectors
10 6 number of FATs (File Allocation Tables)
11 & 12 7 root entries
13 & 14 8 total sectors
15 9 media descriptor
16 & 17 10 sectors per FAT
18 & 19 11 sectors per track
1A & 1B 12 heads
1C & 1D 13 hidden sectors
- 14 tracks per head (derived, not explicit in boot block)
- 15 comment
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1457664 350 512 1 1 2 224 2880 240 9 18 2 0 80 IBM PS/30 Msdos 3.3
730112 350 512 2 1 2 112 1440 249 3 9 2 0 80 Toshiba Msdos 3.2
362496 525 512 2 1 2 112 720 253 2 9 2 0 40 IBM 3.1
368640 525 512 2 1 2 112 720 253 2 9 2 0 40 IBM 3.1 IP's
160256 525 512 2 640 8 1 40 Sanyo 1.? from boot sector
Boot sector from the 160K disc does not make sense
Comcen (ukc) wrote a disc readable by G0
IP's PC-AT clone wrote a 360K floppy readable with /dev/rfdE0.
Owners I'm interested to hear of other owners,
Please contact
me Other Owners include:
- Matt Neely ne99mb70_ERASE@ACS.WOOSTER.EDU (no such user @
2003.12) There's a few other owners somewhere in my
archives.
- Salam of www.vintage.org has a 3rd in the
collection of his museum associate, as of 2001.04.
- Brenda Walker walker _ERASE@ volcano .net wrote 24 Jun
2001: As sister to Bill Jollitz the designer of the Symmetric
375, I too have the machine and know of one other.
- Christopher Cox ccox _ERASE@ endlessnow com wrote me June
2014, with
URL to picture with Serial 375-8507-00024 with floppy
drive
Other People
- Hans-Peter Nilsson hp _ERASE@ bitrange com Maybe
interested in gcc or something, if I can put it on
Internet.
- Bill Studenmund wrstuden _ERASE@ sun510.nas.nasa gov for
ld.old ?
- Bill McKie NASA Ames mckie _ERASE@ sky.arc nasa.gov
People
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Top Of Page
SCS User group contacts from Jordan
Bill Blue (enet bdale) was head of SCS user group
bdale @ 2003.12 has just the PCBs, & will sub. the mail list.
Bill Blue was also a big symmetric (dealer/user?)
Paul Vixie: Much experience of SCS, but now sold his machine to chuck.
Chuck:
Jordan said:
when winchester aged, the 12V 3.5 A power supply was
not enough, needed 4A, so he upgraded to a 5A supply.
Jordan says he has Paul Leaskys machine, & bill blue's,
he said he only has 1.
he has 3 drives, both size floppies, and tape., no ether
Odds
- The manufacturer, SCS (Symmetric Computer Systems) Inc.
is long defunct.
- It was named the 375, in honour of the VAX 750, & SCS
Inc. adverts promoted it as "Half A Vax"
- New price was: $8000 / $9000 with Ethernet + built
in tape, + VT220 clone + cheap nasty matrix printer, or $5000
with built in floppy, but no ether, no vt220, no matrix.
- Designer was Bill Jollitz, whose initials WFJ appear in
block capitals on the circuit board. (william _ERASE@
Berkeley.EDU ) That's the same Bill Jollitz who wrote the
Byte articles, translated into German by CT mag too, about
porting BSD Unix to the Intel PC, which port he called
386BSD, which was the launch point for such great things as
FreeBSD,
NetBSD, & OpenBSD
- They were exhibited at Vintage Computer Fest
Europa, 1st May 2000, & 28&29 April 2001, &
27 & 28th April 2002 & May 3 & 4 2003. The
ethernet machine was exhibited again in 2006.
-
Top Of Page
Floppies - Chucks Labels on
Chuck's floppies received from Paul 930108 (field order
varies in accordance with varied floppy label order)
Contents:
Format:
Vols: 1
Date: 1/28/86
SN: 8504-00049
System: 375
Config: 4.2BSD
FIXIT DISK REV 2.1 wfj/scs
------------------
Contents: Root FS
Format: Dump
Vols: 6
Date: 4/1/86
SN:
System: s/375
Config: 4.2
------------------
Contents: Usr FS
Format: Dump
Vols: 23
Date: 4/1/86
SN:
System: s/375
Config: 4.2
------------------
Contents: 4.2BSD FIXIT Floppy Bootable Floppy UNIX System
Format: 800K Floppy Filesystem
Date: 3/87
Vols: 1
System: 375 4.2BSD
SN: na
------------------
Contents: 375 Electronic Magazine Dump (Winter/Spring 87) Edition
Format: Mountable Floppy Filesy
Date: 6/87
Vols: 1
System: 375 4.2BSD
SN:
------------------
Contents: 375 Electronic Magazine Dump (Winter/Spring 87) Edition
Format: 800K Floppy Dump
Date: 6/87
Vols: 11
System: 375 4.2BSD
SN: 8 on Vol-1, 9 On all others
------------------
Contents: VMUNIX with SCSI (pencilled scs label)
Format: tar
Date: 8/87
Vols: 1
System: 375
SN:
------------------
Contents: TAR VMUNIX scsird scs... (pencilled scs label)
Format:
Date:
Vols:
System:
SN:
------------------
Hand Written non SCS label
Symmetric S375
tar /VMUNIX + tar -xf /dev/rfd0
------------------
Hand Written non SCS label
SYMMETRIC
CST0,CST2
RTC0
1-19-90 CH (Presumably Chuck Hein )
Fix it floppy
------------------
Hand Written non SCS label
SYMMETRIC
CST2
CST0 1/19-90 CH
RTC0
Fix it floppy
------------------
Hand Written non SCS label
UU43N
------------------
Hand Written non SCS label
Finance
-
Top Of Page
26-3-87 i phoned symmetric, spoke to phuong Nguyen
$5k +
475 cartridge
500 scsi card
~300 delivery
~850 if want floppy as well as cartridge
1200 if 85 rather than 50m disc
shipping 2 weeks after receipt of cash
they will apply for an export licence for me.
terry reckons flights to states cost #500 return (12-87)
comparison of buying a basic symmetric, then upgrading, or buying bigger m/c
small big
4995 8095
1000 50m>85m -
- + floppy
600 scsi card
x ether
675 vdu
~350 printer
850 cassette
8470 TOTAL 8375
implies get ether free if all prices are fair, & want lpr + vdu.
--------------------------------------------------------------------------------
87-12-17 Lynne quoted me complete system price (based on the July 1st price list
8095 Complete 375 Software Developers Package
100 Configurable Kernel
20 Ingres
20 EMACS
15 Spice
15 TOP
20 GDB
330 Transport (2nd day air)
280 Floppy
8895 SUB TOTAL
112.5 5 Tapes @ 22.5
9007.5 TOTAL
this system does include the scsi, st506, flop & interface
comes with the schematics for the correct revision
4.3 still beta test, they are doing scsi research to get a more general driver.
Bank Of America
Account Number 14184-9-01338
Palo Alto Corporate Banking Group (CBG)
Palo Alto California
1484-94301
--------------------------------------------------------------------------------
American Siemens programmer with a Symmetric
Dave Mysan
Berlin 011 030 802 5947 (home)
Potsdamerstra~e 8,
1000 Berlin 37.
900629 I tried the number above, no good,
but answer-phone said it was a berlin number, i left a message asking
him (whoever) to ring back.
he has a 90M Seagate,
had the system 2 years,
a year ago it died shortly after returning to berlin from a round trip to the states,
he sent the whole box back to the states,
they fixed the dead drive
he knows a chap called tom kern who `sells programmers' in m}nchen
he said there is no manual documenting the particular pascal dialect used
franz lisp manual is on machine
fortran 77 has no manual
he has a connection to bitnet (post don't know)
he mentioned the 875,
--------------------------------------------------------------------------------
i phoned Lynne to ask what the 875 was,
the 875 will be a pedestal mounting box, sold to VARs, clipper based, available
2 1 88, later in the year a clipper upgrade for the 375 will be released
$5000 8MIPs
--------------------------------------------------------------------------------
87-12-19 exchange rate approx 1.63 dm = $1
Lynne Mesner 9.40 am wed 12 dec. 12.30 ie 30th dec.
+ 1 415 651 6090
no money in her bank on 29th no mention of receiving my letter
2nd call, transfer had gone through will ship within 1 to 1.5 weeks
phoned Lynne, gave her a hard time, she put me on to Bill Jollitz
88-01-15 I phoned they are waiting for a better tape drive Mon./tues, then will ship,
I get 4.3 free later, (other customers pay $1K) my machine on test, ok except tape drive.
cant have 4.3 yet as there is a problem with signals & fp
--------------------------------------------------------------------------------
88-01-28 Symmetric delivered.
--------------------------------------------------------------------------------
88-01-After receipt teac +49 8152 39101 Mr Okada phoned me
--------------------------------------------------------------------------------
900629 IDQ phoned USA, there is no firm called Symmetric in fremont,
900629 00 1 415 651 6090 no answer @ 18:50(mu)=09:48(usa)
--------------------------------------------------------------------------------
90-10-11 Jordan confirmed Symmetric had gone belly up!, but there is a Sym. users group
--------------------------------------------------------------------------------
Chip page by Udo @ 2017-09-04 http://www.cpu-ns32k.net
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