Frequently asked questions and hints about the AT&T UNIX PC (1 of 2)
Lenny Tropiano
lenny at icus.ICUS.COM
Fri Sep 28 09:31:11 AEST 1990
------------------------------------------------------------------
Answers to some frequently asked questions about the AT&T UNIX PC,
as well as some frequent problems and useful hints with them
------------------------------------------------------------------
Last updated: Thu Sep 27 19:10:00 EDT 1990
by Lenny Tropiano, ICUS Software Systems,
<lenny at icus.ICUS.COM>
This file is not just for the novice UNIX PC user, there are
helpful hints for everyone, from the novice to the most
experienced users. Please email me any suggestions, additions
or corrections that you may have.
______________________________________________________________________________
1. What are the AT&T UNIX PC, PC7300, and 3B1? Which do I have?
UNIX PC and 7300 were the AT&T marketing terms for the original machine,
with 10 or 20MB hard disk. 3B1 is a more recent name, particularly for
the 40MB and 67MB model. The 40MB and 67MB 3B1 also has a different top
cover, more than 512K on the motherboard (generally 1MB or 2MB standard),
and a higher-rated power supply. "Safari" was the development code name.
"UNIX PC" refers to all machines in the family.
The model number should be on the name plate on the bottom of the machine.
When the keyboard is on the housing, the 7300 case is a slanted wedge
shape. On a 3B1, the monitor is mounted on a square horizontal box
protruding above the slanted top of the wedge. This is because the 40MB
and 67MB hard disk is a full-height disk, whereas the 10MB and 20MB, in
the PC7300, was a half-height disk.
The 3B1/UNIX PC/PC7300 was developed and built by Convergent Technologies,
and was called the S/50 by CT. Convergent Technologies sold the rights
to AT&T to resell the S/50, which was dubbed as the PC7300, 3B1, or
UNIX PC by AT&T.
2. I mailed the card to AT&T and did not get my Personal Calendar program.
(Don't bother mailing anything to AT&T now that refers to the UNIX PC,
the product line has been manufacturer discontinued for quite some
time now)
David Brierley <dave at Galaxia.Newport.RI.US> says, "I got mine!! Of
course, the manual reflects the version that is mailed out on the
floppies, not the updated version that is actually loaded onto the
machine."
Many machines were shipped with the calendar program in /etc/fixes.
You have to do a few things to install it.
Append this to your /usr/lib/ua/Office file:
Name=Calendar
Default = Open
Open=EXEC -d /usr/bin/pcal -c
Help=EXEC -d /usr/bin/uahelp -h /usr/lib/ua/ua.hlp -t Calendar
Append this to your /usr/lib/ua/Preferences file:
Name=Calendar
Default = Open
Open=EXEC -d /usr/bin/pcal -p
Help=EXEC -d /usr/bin/uahelp -h /usr/lib/ua/ua.hlp -t Calendar
If you are using the pcal that is located in /etc/fixes:
$ su
Password:
# mv /etc/fixes/pcal /usr/bin
# mv /etc/fixes/pcal.hlp /usr/lib/ua
# chown bin /usr/bin/pcal /usr/lib/ua/pcal.hlp
# chgrp bin /usr/bin/pcal /usr/lib/ua/pcal.hlp
# chmod 755 /usr/bin/pcal
# chmod 644 /usr/lib/ua/pcal.hlp
3. How do I park the hard disk heads before moving the machine?
The Miniscribe and Hitachi disks used in the 40MB and 67MB machines
parks the heads automatically, and loudly, when the power is turned off.
Also note that many newer drives have auto-parking mechanisms,
check with your specific manufacturers for more information.
If your drive doesn't auto-park (many Seagates don't), or you want
to make extra sure that they heads are in the parked position --
after the machine is shutdown, insert the Diagnostics floppy disk
and boot from it. Select Park Disk Heads from the Diagnostics menu.
4. How do I open the case? How do I get to the motherboard (for the
suggested preventive cleaning out of the "dust bunnies")?
The obvious screws on the bottom allow either removal of the top of
the plastic case or removal of the plastic case from the metal base.
Different screws release the plastic case or only the top (the part
above the keyboard storage area). Read the following several paragraphs
before removing anything other than the first step: unplug everything
from the back. (Oh, yeah: "No user serviceable parts inside" -- but
that all depends on the user!)
First find the keyboard retainer posts (they hold the keyboard to the
base--one is next to the socket for the keyboard plug). Note the seam
around the top of the retainer posts. Remove the covers from the posts,
and you'll find a screw inside each. Remove those screws before
removing the screws on the bottom of the machine.
When removing the top of the plastic case, there are two or three
plastic hook-and-tab catches in the front of the machine, to the right
of the floppy drive. The top of the case must be moved outward slightly
(usually with a screwdriver or finger pressure) along the joint to the
right of the floppy drive in order to release the catches. This exposes
only the floppy drive, the hard disk (underneath the shielding) and
power supply.
The three screws in the front of the motherboard shielding should be
removed (if you want to expose the motherboard), and then remove the
screw holding the 10-pin video cable from the monitor (left side of the
motherboard shielding). The video connector can be removed from the
left side of the motherboard. Then remove the ribbon-like cable that
connects the motherboard to the power supply (on the right side of
the motherboard). After that the metal shielding can be lifted
and slid along the tracks and then flipped up or removed. This exposes
the motherboard. If you need to remove the motherboard shielding
completely and the monitor assembly, you need to disconnect the floppy
and hard disk cables from the motherboard (note the direction of the
connectors, and when replacing them be very sure that the 20-pin
and 34-pin connectors are seated correctly on the associated pins).
If you have a PC7300 power supply, and motherboard, you're floppy
drive power cable might be connected, as well, to the motherboard.
To remove the whole assembly, in that case, you'll need to remove
the power connector from the back of the floppy drive as well.
*** BE VERY CAREFUL WHEN EXPOSING ANY COMPONENT OF THE UNIX PC, THERE
*** ARE MANY STATIC SENSITIVE COMPONENTS, PROPERLY GROUND YOURSELF
*** BEFORE POKING AROUND INSIDE!
Be extra careful when placing the top of the UNIX PC/3B1 back on the
machine, a common cause for the machine not powering up after the cover
is replaced is the 120VAC connectors (brown and blue wires crimped on)
have fallen off the power input. Make sure they are crimped on tightly
before closing the case. Also be careful of the green ground wire, it
has a tendency of getting caught in the fan blades (causing the fan not
to start spinning when the machine is turned on) or caught in the case
itself. Be sure everything is working (including the fan) when you
close the case and before you fasten the 4 screws.
5. How can I put in a larger hard disk drive? Will this increase the speed
of my machine? What is the largest disk possible in the UNIX PC?
Upgrading from a 10MB, 20MB, or 40MB to a 67MB drive requires a 3B1
power supply and a 3B1 case top (the 40MB and 67MB drive is full-height).
There are other solutions to this, you can get half-height drive that
are faster than 80ms seek time (which the old 10MB and 20MB drives were)
and have more disk space. As long as the drive is a ST506/MFM interface,
and is less than or equal to 1024 cylinders and less than or equal to
8 heads, the drive will work without *any* hardware modifications.
To upgrade to a disk, >8 heads and >1024 cylinders there are several
approaches one can take. Gaining more cylinders is the easiest of
upgrades, all you need to do is replace the WD1010 disk controller
(which is socketed on the motherboard at location 21H) with the
pin-for-pin compatible disk controller, WD2010. The WD2010 comes in
several varieties, and all seem to work for the most part (WD2010A,
WD2010B, etc.). There has been some discussion in unix-pc.* that
people haven't been able to get the WD2010 to work in their older
revision motherboard UNIX PC or PC7300. These machines have a
daughterboard that handles the disk circuitry, instead of the
all-in-one chip that was replaced in the later models. I haven't
been able to verify this, since my all my experience is with newer
releases of the motherboards.
The operating system, from at least release 3.0 of the operating system
supported an unreleased motherboard revision P5.1. The P5.1 revision
level (like the P3...P5 that you see during the boot phase) includes
some extra features such as an extra disk head (expanding to 16
read/write disk heads) and extra drive select (giving the UNIX PC the
capabilities of expanding to two simultaneous hard disks). With the
appropriate hardware modifications (all requiring some expertise in
soldering and reading schematics), one could upgrade their motherboard
to emulate this undocumented motherboard revision. These upgrades
weren't released to the public by either CT or AT&T during the
life-cycle of the product, but was later released and made public by
several people in several different forms.
o ICUS Software Systems, Gil Kloepfer, Jr <gil at limbic.ssdl.com> and
Lenny Tropiano <lenny at icus.ICUS.COM> offers plans to upgrade your
machine to P5.1 status, and details on how to wire your motherboard
and build your own circuit to allow two hard disks (maximum of
16 heads) to be utilized by the UNIX PC. The information on how to
obtain the kit is available on Ohio State University's UNIX PC
Archives as ICUS_HD2.Z. If you cannot obtain that, you should
contact either Gil or Lenny for additional information. The plans
cost $30.
o John Milton <...!cis.ohio-state.edu!n8emr!uncle!jbm> has a prebuilt
circuit board that offers up to 4 hard disks and 2 floppy drives, but
be forewarned that the operating system only supports the two
hard disks and one floppy drive. If the operating system patches
could be made, John's hardware will support it. He's offering a
prebuilt, and pretested board that can be wired into the motherboard.
The motherboard wiring (jumpers) and soldering will have to be done
as well before you can use John's board (this is not a plug in and
go situation -- it requires some time to wire). The board and
instructions cost $75.
o FIELD P5.1 PAL upgrade. The P5.1 instructions were posted to
unix-pc.general a long time ago, and are now archived on OSU in
the P5.1.Z file. This requires a preprogrammed PAL chip to be
made, which is available for $6.00 from Brian Botton
<...!laidbak!botton>.
The largest disk in the UNIX PC/3B1 is:
o Motherboard revision P3...P5 (WD1010 disk controller)
8 heads x 1024 cyls x 16 sectors/track x 512 bytes/sector = 67.1MB
o Motherboard revision P3...P5 (WD2010 disk controller)
8 heads x 1400 cyls x 16 sectors/track x 512 bytes/sector = 91.7MB
o Motherboard revision P5.1 (modified) (WD1010 disk controller)
16 heads x 1024 cyls x 16 sectors/track x 512 bytes/sector = 134.2MB
o Motherboard revision P5.1 (modified) (WD2010 disk controller)
16 heads x 1400 cyls x 16 sectors/track x 512 bytes/sector = 183.5MB
NOTE: 1400 cylinders if the #define HDMAXCYL in /usr/include/sys/gdisk.h,
although the WD2010 can support up to 2048 cylinders, the operating system
cannot. Also with the multiple hard disk upgrades, mentioned above, you
can have two disks that can be as large as the above sizes, for the P5.1
modified motherboard revision.
6. I heard about something called THE STORE! that contains archived
UNIX PC software, how can I access it?
THE STORE! is no longer available for dialup uucp, which was owned and
operated by AT&T. All publicly accessible software that was formerly
available there has been moved and archived on the OSU archives (see
below).
7. The On-Board Modem (OBM) does not work with some other modems.
The OBM creates the answerback tones which says for some reason
that it's a MNP reliable modem?! This confuses some MNP modems and
the Telebit Trailblazer (only if set in MNP reliable mode). These
cannot be altered in the OBM, but often a system which cannot call
the UNIX PC OBM can be called by the UNIX PC OBM.
8. What is the operating system? Its origins?
The operating system is based on UNIX System V Release 2, with
extensions from BSD 4.1, BSD 4.2, System V Release 3 and
Convergent Technologies. The most recent version is 3.51, with
a 3.51m FIXDISK (2.0) available. The FIXDISK can be gotten from
AT&T directly, they will send it out to you free of charge. Just
call the Hotline Support line at 1-800-922-0354, and tell them
you want the free FIXDISK 2.0 for the UNIX PC. The FIXDISK is
also available on OSU Archives as FIXDISK2.0+IN.
Changes in 3.51a FIXDISK 1.0: (all changes are also included in
the later release FIXDISK 2.0 -- see below)
New problem: Your machine will occasionally crash with a "panic: addr
fault in kernel" message, but _only_ if you have installed 3.51a _and_
you use the OBM (On Board Modem). If you use a modem attached to any
serial port, you'll never see the problem. It is recommended that you
upgrade directly to 3.51m. The 3.51a release is not a prerequisite
for 3.51m, only 3.51 is.
Hardware flow control works, but is broken. HFC will consistently
repeat a block of data in an entirely predictable way.
The terminal emulator (/usr/bin/async_main) has fixes for the
following:
- lockfiles not being removed
- vt100 enter key mapping incorrect
- slow performance when using 513 or vt100 emulation
The UNIX PC 3.51a Custom Kernel (/UNIX3.51a) has fixes for the
following:
- tty driver does not return null character on break
- break sent over modem freezes serial port
- lp driver truncates lines to 132 characters
Kmap (/usr/lib/ua/kmap.610) corrects the misspelling of RollDn in
the kmap file for the 610 terminal.
Ksh (/bin/ksh) has fixes for the following:
- dumps core on long input lines while in emacs mode
Modemcap (/usr/lib/uucp/modemcap) has an entry for the AT&T 4024
modem.
The Phone Manager (/etc/ph) has fixes for the following:
- ph stops logging calls in .history
- call screen pops up
- ph dies after several calls
The tam library (/usr/lib/libtam.a) has the following:
- newly developed applications linked with the new
tam library can draw windows/contents in one pass
instead of two
The uucp (/usr/lib/uucp/uucico) has fixes for the following:
- uucico hangs at call completion
- uucico turns modem speaker on
- time stamps incorrect in LOGFILE
Changes in 3.51m FIXDISK 2.0:
Fixes found within /unix (/UNIX3.51m):
- changed print to eliminate false data in unix.log
- SDLC speedup
- problems with panics due to clist corruption
- fix for the System V "losing i-node" problem.
- more lines to register dump (from "panic"):
inadequate data was being supplied for fault analysis
- altered invalid page-fault address test
- increased NMOUNT to 8 for users with LARGE or multiple disks
console driver:
- added fix for lock-up during '--More--' processing of diagnostic
output ("once again")
hard disk driver:
- fixed error reports & added >8 head/2nd disk data
(/usr/adm/unix.log)
- added identification of disk controller (either WD1010/WD2010)
- added gdhdprecomp[] to support variable PreComp and 2 disks
- added step rate code to permit other than 0
floppy disk driver:
- added fix from Peter Fales
tty device driver:
- Fixed IXANY in test [as posted to USENET by Peter Fales]
keyboard driver:
[LBT's note: if you are currently using the kbd.o device driver
from either Mike Ditto or from THE STORE! it should be removed
and unloaded to access the following "features" of the new
kbd driver in the kernel]
[David Brierley said, "I continued to use the Ditto kdb driver
after installed 3.51m and the machine started to act a little
weird, mostly in relation to the caps-lock and num-lock keys.
Sometimes pressing caps-lock or num-lock would have no effect
and frequently they would light up the corresponding LEDs when
pressed the first time but neglect to turn them off when pressed
the second time. Unless there is something weird about my
machine I would say that the Ditto kbd driver is incompatible
with 3.51m. I don't know about the version from the STORE."]
- changed debugger trap from "compiled-in" Control-B
to match DBtrapshort kernel location -- defaults to Control-B.
- added save unblanking character (symbol savUBkey) -- defaults to 0.
if user resets to 1, screen restore char will *NOT* be discarded
from input stream.
- added triple-key special functions [see below]:
triple key sequence = left ctrl + left shift + caps lock + Fn
F1: Identifies keys (and those which are "ON") [help line]
F2: Toggles Caps Lock and Right Control keys reversal
F3: Toggles Meta-key mode (Left Control becomes Meta)
F4: Toggles Save-Unblanking-Char mode
F5: Toggles Ramped AutoRepeat speed
F6: Toggles "MeterMaid" display
[LBT's note: "What is metermaid you may be asking?
Metermaid info is in a "hints" file on OSU]
(if db.o is a currently loaded device)
F7: Toggle use of Kernel Debugger Escape Key
(traditionally a Control-B)
F8: Trap into Kernel Debugger(w/o using Escape Key)
- changed several keys' Control-* value to provide
better access to 0x00, 0x1e, 0x1f binary values.
Previous Now
- CONTROL-DELETE: <Illegal> -> 0x1f
- CONTROL-SPACE: <SPACE> -> NULL
- CONTROL-'.': <Illegal> -> 0x1e
- CONTROL-'/': <Illegal> -> 0x1f
lp driver:
- state-logic code was rewritten entirely to try to make code more
predictable. (this will slightly alter sequence of
Error/Paper-Out [!!] messages)
mem driver:
- fixed error in MPTE-loading [Peter Fales]
- fixed error in upper-address limit test [Peter Fales]
tty line discipline:
- fixed error in IUCLC handling
- added code to prevent lockup during _VERY LONG_ lines submitted
under canonical processing
- fixed CLIST-loss problem in 'canon()'
- altered delay() call to reflect SVR3.2
Loadable Window driver (wind.o):
- changed 'char' in kspecial to 'unsigned char' to avoid problems
with Meta-type characters (ie. ones with high-bit set)
- mouse's presence is tested after the screen is unblanked (from
previously blanked condition) and will not display mouse pointer
if not connected
Loadable Combo driver (cmb.o):
- cleaned up driver code.
/etc/magic
- corrects erroneous information from earlier versions.
Asynchronous Terminal Emulator fix (/usr/bin/async_main):
- lock files not being removed
- vt100 enter key mapping incorrect
- Slow performance when using 513 or vt100 emulation
- Character echo problems with System75 PBX's
- Remote terminal usage with the Call Screen
/bin/date:
- If the system battery is dead (the time reverts to
January 1, 1970), the replacement 'date' command will
reuse the time stored in the filesystem superblock.
kmap fix (/usr/lib/ua/kmap.610):
- Misspelling of "RollDn" in the kmap file for the 610 terminal.
ksh fix (/bin/ksh):
- dumping core on long input lines while in emacs mode
modemcap fix (/usr/lib/uucp/modemcap):
- an entry for the AT&T 4024 modem.
Phone Manager fix (/etc/ph):
- call screen pops up
- /etc/ph dies after several calls
- /etc/ph stops logging calls in .history
Remove script:
- Inserts a confirmation window which allows the
user a chance to cancel the removal (in case the
wrong item was selected).
/usr/bin/scrset:
- problems with the data under certain screen blanking
sequences.
/usr/bin/setgetty:
- prevent corruption or removal of /etc/inittab
tam library fix (/usr/lib/libtam.a):
- Newly developed applications linked with the new
tam library can draw windows/contents in one pass
instead of two
Floppy Tape fix (Tbackup.sh):
- can't remove tape to insert tape 2
- verify pass checks tape contents (not just whether
it is readable)
utmp fix:
- shutdown problems, multiple bogus entries in /etc/utmp.
- corruption of /etc/utmp file.
uucp fix (/usr/lib/uucp/uucico):
- uucico hangs at call completion
- uucico turns modem speaker on
- time stamps incorrect in LOGFILE
9. What third-party hardware is available?
Presently there are no known distributors that have a selection of
UNIX PC hardware. The best source for hardware is the network,
reading unix-pc.general and misc.forsale. There is always someone
selling UNIX PCs and the appropriate hardware expansion.
10. a) I'm trying to set up a printer on my UNIX PC using the lpadmin(1M)
and accept(1M) command, but they aren't working -- no messages at
all.
b) All the jobs on the printer are always followed by a formfeed (FF).
c) I cannot send bitmapped images to the printer correctly.
The lpadmin(1M), accept(1M), and reject(1M) commands require the user
to be logged in (or su'd to) user "lp". Being su'd as root will not
work.
# su lp
$ /usr/lib/lpadmin -plp1 -mdumb -v/dev/lp
The line printer driver will follow each close() to /dev/lp with a
formfeed. There is no way to disable this. The only way is to set
up the printer as the raw device.
$ /usr/lib/lpadmin -plp1 -mdumb -v/dev/rawlp
8-bit bitmapped images need to go to the raw device, as well.
11. Can I put a 68881 math coprocessor in my machine? I saw AT&T had
one for the UNIX PC?
AT&T (or Convergent Technologies for that matter) never fully developed
the 68881 floating point math accelerator processor. The board was
rumored to sell for ~$2,000 and not increase the performance to the
machine.
12. Where can I get GCC and G++ for the UNIX PC? Has someone already ported
it? (Also see item #40)
Yes, GCC (GNU C Compiler) has been ported to the UNIX PC for quite some
time. It's up to release 1.37.1 currently, and has few bugs. The
unfortunate thing is that the compiler is very large in size, so programs
do take quite a bit longer to compile.
There is also a G++ (GNU C++ Compiler) as well. Both are available as
installation archives from the OSU Archive site (see below).
The national GNU archive is located on the Internet at prep.ai.mit.edu.
They allow anonymous FTP transfer. This is where you will find the
FSF (Free Software Foundation) founded by Richard Stallman, software
archives. You'll find gnu CC, gnu C++, emacs, gnu chess, gnu groff, etc.
there.
13. Has someone ported X-windows to the UNIX PC? What's MGR? What can it do
for me?
No, X has not been ported, and probably won't ever be ported the UNIX PC.
X is quite large, and there has been several discussions about porting
it in unix-pc.*, but it's probably not worth the efforts.
MGR is an alternative windowing environment, developed by Steve Uhler
at Bellcore, and ported to the UNIX PC by Brad Bosch and Brian Botton.
The MGR windowing environment can replace the standard /dev/window
environment on the UNIX PC quite nicely (it does prevent some UNIX PC
specific program from being run in this phase, without the wind.o
loadable device driver loaded). MGR's user interface is quite similar
to a SunWindows environment, and raster operations are quite fast.
MGR is a user program, no driver (besides the pty driver), so it's
not taking up precious kernel space. It does require a hardware
modification called the VIDPAL. The VIDPAL (developed by Brian Botton
<...!laidbak!bilbo!botton>) is a daughterboard that sits sandwiched
between the 68010 CPU and the motherboard. Brian provides the kits for
$25.00, that will allow on direct access to video memory (required
for the MGR windowing environment). This upgrade is simple to complete,
and is easily reversible.
MGR is still beta, and can be gotten by anonymous ftp from:
max.physics.sunysb.edu [129.49.21.100] on the Internet.
14. How can I get a full 360K when I format a MSDOS floppy on the UNIX PC,
normally I just get 320K? Are there better utilities to manipulate
files to and from UNIX and MSDOS floppies?
$ windy /usr/bin/md_format -9
A suggestion is to get "windy.cpio.Z" from the OSU Archives to run this
program since if "windy" is left off the command line your window
will be in an "insane" state after the floppy is formatted.
Moving files to and from a MSDOS floppy with the standard UA-interface,
isn't the easiest or most efficient. Thanks to Emmet P. Gray
<egray at fthood.UUCP> and his MTOOLS program (available on OSU Archives)
you can copy, take directories, delete, and move files easily between
the UNIX filesystem and the DOS filesystem. In the newest release
(MTOOLS 2.0), Emmet supplied us with mformat, a tool that will format
floppies as well. It formats 360K, 720K, etc. MTOOLS 2.0 also supports
the C:, D:, etc. drive partition from the DOS-73.
15. My archives are old (archivelib.a) reports that is it's a 5.0 archive,
and it doesn't link (ld) very well with my other archives.
The archive format was changed from release 3.0 to 3.5 of the operating
system. There is an utility to convert the archives to the new format.
# convert oldarchive.a newarchive.a
Or you can run:
# arconvert
# file oldarchive.a newarchive.a
oldarchive.a: 5.0 archive
newarchive.a: 5.2 archive
And that will convert all the archives in /usr/lib and /lib that are
old 5.0 archive format to the new 5.2 archive format.
16. How do I get my on-board modem to only be a dial out modem, and not
answer? (I share my voice line!)
The easiest way to do this is to edit (with your favorite editor)
the /etc/inittab file. Change the line:
ph0:2:respawn:/etc/getty ph0 1200
to:
ph0:2:off:/etc/getty ph0 1200
^
NOTE: There is a blank (space) in front of the first "ph0" in the
lines above. ph0 may be ph1 if you are using line 2 for the
on-board modem.
17. Does my on-board modem support 2400? I see stuff in the /usr/include
files that reference 2400 baud internal modem?
In what Convergent considered future releases of the UNIX PC (P6), there
was to be a 2400 baud modem. This machine was never fully developed to
production levels, and therefore there is no 2400 baud modem. The
machine was to have a color video, 60MB QIC tape, as well as a 68020 CPU/
68881 FPU.
18. What do the LED's mean on the left side of my machine (through the grill
or grating?)
This is from John Milton's HwNotes series #1.
0 RED: This is the "user LED". It can be turned on and off with the
syslocal(2) call. It is not used by any existing applications.
1 GREEN: This is the one most people get wrong. This LED toggles every
time there is a process context change, and is cleared on the
whole second
2 YELLOW: This is the idle LED. When it is on, there are no processes in
the ready to run state.
3 RED: Heart beat LED. This is toggled on the whole second.
Additional information is available in the HwNote series 1-15 that are
archived, yes you've guessed it, on OSU.
19. Can I really get 4MB of memory, even with a 1.5MB combo card, 512K RAM
card, and 2MB of RAM on the motherboard?
The answer is yes. It does require a simple pin-ectomy. You need to
fool the hardware to think the 512K RAM card is in a slot that doesn't
physically exist on the UNIX PC. For more information on how to do
this, grab John Milton's HwNote06 from the archive sites.
20. I'm getting all kinds of HDERRs in my /usr/adm/unix.log file. What
should I do? I also see from time to time lots of FDERRs (or
possibly TPERRs), what are those? (regarding FDERRs also see #41)
There have been several causes for this. One of course is a bad disk,
or a disk that has gone bad. But one should check the other options
before determining the disk is really bad.
Dirty power supply contacts have been known to cause these problems.
Open the machine (see frequently asked question #4) and clean the power
supply contacts on the ribbon-type cable that goes from the supply to
the motherboard.
A weak or faulty power supply too could be your problem. Test the
power supply voltages (with the hard drive and motherboard connected
as a load), using some sort of Y-connector off the power cable to the
hard drive. Test the +12VDC and +5VDC supplies with a meter, and
make sure they are within acceptable tolerances. If they are too low,
intermittent HDERRs will occur. There are several adjustment screws
on the power supply (marked +5, +12, -12) that can adjust these values.
Turning clockwise will increase the value, and counterclockwise will
decrease it. Faulty power may make a good hard disk or motherboard
appear to be bad.
More commonly you'll find FDERRs in your /usr/adm/unix.log file.
Every time you format a new floppy disk, you'll get at least one.
Floppy disks are prone to more errors, especially if you get those
bargain basement brand type. (I suggest a reliable brand if you
depend on floppy disks for backups).
TPERRs might appear if you have a bad or defective cartridge
tape block. If you start seeing a lot of these during your backup
or verify phases, I suggest re-formatting the tape and running
another surface check (to check for possibly bad streams, or good
streams that have gone bad).
21. Can I hook up a 3.5" 720K floppy drive to my UNIX PC? How about
a 1.2MB or 1.44MB floppy drive? Can I run both the 3.5" drive and
the 5.25" drive on my machine somehow?
Yes, to the 720K. No, to the 1.2MB and 1.44MB.
Putting a 720K 3.5" floppy drive is rather simple, if you are just
replacing the exist 360K 5.25" drive completely. In most cases it's
a one-to-one swap, providing you can get the jumper setting set
correctly on the 3.5" drive.
You can run both drives, provided you make a mechanical switch (SPDT)
to change the drive select between the 5.25" 360K internal drive and
the 3.5" 720K (run externally). You need to make a cable to switch the
pin 10 (FDRIVE0*) from one drive to the other. Drilling a hole in the
case above the left fan grate is a suitable spot.
When you use the 720K drive, all you need to do is create an iv
description file that has 80 cylinders instead of 40, and you get the
full 800K (80 tracks, 10 sec/trk). Makes backups go faster!
22. I've heard bad things about the stock 12VDC fans? Should I add another?
Replace it with an 120VAC fan? I hear my fan is going from low to
high speed sometimes -- what is this?
The fans have been a problem with the UNIX PC in a lot of cases. What
happens is the 12VDC fan is connected to a thermal switch that will
alter the speed of the motor when the machine is hot (faster when hot),
and slower (when cool). I've seen and personally experienced the fan
going from fast to slow to off. The fan collects a lot of dust and
dirt, and sometimes when switching to the slow speed, it is goes so
slow that it stops, and doesn't have enough "umph" to start up again.
Gil Kloepfer theorizes the reason for this happening is that the 12VDC
fan is constantly running with too little current due to a resistor
wired in series with the power supply when the thermal switch is in
its normally open position. When the fan is beginning to malfunction,
it will run subtly slower, but enough to keep from moving enough air
through the machine. The thermal switch kicks-up the power, which
causes the fan to move faster and cool the machine down until the
switch kicks-out again. This cycling effect keeps going until the
fan become excessively weak and clogged with dirt to where it eventually
stops working permanently. But he goes on to add that, in any case,
I don't think it's just dirt.
The next stage is the machine overheats, the power supply cuts out,
and the machine powers down, then it powers up, and down, and up.
If you are lucky you catch this before major damage occurs, or you
take preventive measures beforehand. Most of the time the power supply
gets so hot, it dimples the plastic case above it. This is a sure
sign that the UNIX PC has had a "meltdown" before.
What can you do? Well you can replace the 12VDC fan with a 3" 120VAC
fan. The 120VAC fans are more robust, they produce more air current
(~34CFM normally) and don't draw on the power supply any. One drawback
is they are noiser. The PC7300 cases had two 12VDC fans -- in my
opinion thats double trouble.
Some people can go years or forever without ever having a problem, but
it just takes that one day that you aren't around and the machine
goes into "meltdown" and then you'll be assured some damage somewhere.
Radio Shack has an appropriate 120VAC fan for $16.95, cat. no. 273-242.
23. My machine is booting over and over? It keeps complaining that
Stored Files are being checked, and then it reboots.
The stock /etc/rc that called when the machine boots up, writes the
output of the fsck(1M) to the hard disk (/etc/.lastfsck). This is
definitely a problem. I prefer having control over what fsck does,
instead of sending fsck with the "-y" option and having it do all
the work. A lot of times fsck will delete files or clear them and
you have no control over what it's doing.
Check out the fsokay.cpio.Z package on OSU, it contains some enhanced
/etc/rc scripts and tools to make the booting phase of the UNIX PC
a lot cleaner and more reliable.
24. The stock uucp with the UNIX PC is the pits, where can I get HDB?
(HoneyDanBer UUCP).
HDB binaries are available from the ~/att7300/STORE/HDB3.5+IN.Z on OSU.
25. What is OSU-CIS? Is everything archived there? How do I connect to it?
OSU is a Ohio State University's Computer System and Lenny Tropiano
<lenny at icus.ICUS.COM> is maintaining the archives. There is a
very large selection of programs that were posted to unix-pc.sources,
some that were not, and some that are too large to post. There are
sources, binaries, hints, patches, suggestions, and a lot of good
information for UNIX PC/3B1/PC7300 owners.
There is a monthly posting regarding access to OSU-CIS's computers
via dialup uucp, anonymous FTP (Internet) and e-mail server that is
posted to unix-pc.general and comp.sys.att [by the 1st of every month]
Connect up to OSU-CIS by one of those means, and grab a current copy
of the ~/att7300/README.Z file for more information on what is archived
there.
26. Who supports these machines? Are there any user groups that I can
attend?
You see it! We (the net) supports them, there are a lot of dedicated
people who enjoy these machines and post a wealth of information to
the network. If you aren't connected, get connected! The unix-pc.*
groups, although considered an alternative sub-network, is carried by
many backbone sites, as well as most UNIX PC sites running news (leaf
nodes). Reading these groups could be your doorway to the answers
you desire! If you aren't running news, but still desire to read
the group (or even post for that matter), you can receive it by
electronic mail, providing you can receive e-mail. For more
information on receiving "unix-pc.*" by e-mail, contact:
{ames,pyramid,vsi1}!zorch!unix-pc-request (Scott Hazen Mueller)
unix-pc-request at zorch.SF-Bay.ORG
If you are in the Silicon Valley area, contact Thad Floryan
<thad at cup.portal.com> for information on how to go to the
"AT&T UNIX User's Group meeting", the fourth Wednesday of every
month. Although it's a generic AT&T UNIX group, 80% of the members
own UNIX PC's, as well as Thad, who runs the group.
27. Where can I get my machine serviced? Fixed?
AT&T will still support the machine for another year or so, they have
to by law. Their prices are a bit "high" but, they will come on site
or you can bring your machine to a local depot to replace or repair
anything that is wrong with your UNIX pc. Call 1-800-922-0353
(AT&T Hotline support) -- consulting fees will be required to talk
to an engineer, and if it's diagnosed to be a hardware problem the
consulting fees will be waived. Caveat Emptor (let the buyer beware).
They tend to like to replace lots of parts. For a $3.00 battery,
they'll replace the motherboard (not cheap!)
A better solution, at least a cheaper one is the ``A Small Computer
Repair Company'' (ASCRC). I know the people who run the operation,
and they are quite reputable and efficient. They will diagnose
you problem, and repair or replace the part that is broken. They
will try their hardest to repair the item first. Their prices
are much more reasonable than AT&T's, but the catch is you need
to send the computer (or just the component in question) to them.
They will repair/replace it and ship it back. Their turn-around
time is usually 48-72 hours. They repair AT&T's 6300, 6300+, 7300,
3B1 and UNIX PC computers.
For more information and/or to arrange servicing, contact:
A Small Computer Repair Company
5762 Dichondra Place
Newark, CA 94560
or call either:
(415) 430-9226 or (415) 793-6980
28. My clock stopped? What's wrong?
Your battery is dead. On the UNIX PC motherboard there is a 3.0 VDC
lithium battery. That battery keeps the RTC (real time clock)
operating. Unfortunately the battery is soldered to the motherboard,
in most cases. It's either the round cylinderical canister type,
or more commonly the flat disc shaped battery. A suitable replacement
can be purchased at Radio Shack, but you'll need to get the disc
battery holder. If you desolder the battery from the motherboard,
solder in the holder, future replacing of this battery will be much
simpler. If you are nervous about touching a soldering iron to
your precious machine, ASCRC will do it for you (see above).
29. I have a X number of floppy disk backup with all of my hard disk
on it, and I tried to restore it, on one of the floppies in the
middle I got a "Out of phase -- get help" message, what can I do??
Yes! Get the public domain program called "afio". It's available
in the OSU archives. It supports reading the floppy disk backup set,
and will (providing you use the "-k" option) ignore errors and
recover when it finds the next CPIO ASCII header. The backup set
must be written using CPIO and the "-c" option must have been used
during the writing of the diskettes.
Syntax for afio to restore is:
# cd /
# afio -ivk /dev/rfp021
^ k - option to allow dealing with corrupted archives
--
[Continued in FAQs part 2 -- As of September 21, 1990, this was split into
two files since the FAQ became increasingly large]
--
| Lenny Tropiano ICUS Software Systems lenny at icus.ICUS.COM |
| {ames,pacbell,decuac,sbcs,hombre,rayssd}!icus!lenny attmail!icus!lenny |
+------ ICUS Software Systems -- PO Box 1; Islip Terrace, NY 11752 ------+
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