Answers to UNIX PC Commonly Asked Questions
Scot E Wilcoxon
sewilco at datapg.MN.ORG
Fri Nov 4 05:24:53 AEST 1988
Archive-Name: 3b1list
This article contains answers to frequently asked questions about the AT&T UNIX
PC. It is regularly posted to comp.sys.att and unix-pc.general. The following
items are addressed in this posting:
1. What are the AT&T UNIX PC, 7300, and 3B1? Which do I have?
2. I mailed the card to AT&T and did not get my Personal Calendar program.
3. How do I park the hard disk heads before moving the machine?
4. How do I open the case?
5. How can I put in a larger disk drive?
6. What is THE STORE! and how do I use it?
7. The On-Board Modem does not work with some other modems.
8. What is the operating system?
9. What third-party hardware is available?
10. How can I make a full-screen window?
11. Some AT&T serial boards do not work right. How are they identified?
--------------------------------------------------------------------------------
1. What are the AT&T UNIX PC, 7300, 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, for the 40 and 67MB models. A
3B1 also has a different top cover, a slightly different motherboard than the
original, more than 512K on the motherboard, and a higher-rated power supply.
Convergent sold the machine under the S/50 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 40 and 67MB hard disk is taller
than the 7300 hard disk.
2. I mailed the card to AT&T and did not get my Personal Calendar program.
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 disk used in the 67MB machines parks the heads automatically, and
loudly, when the power is turned off. Some 40MB drives also park automatically.
To park the heads push the Cmd key and select Shutdown. After the machine is
shut down, insert the Diagnostics floppy disk and boot from it. Select Park
Disk Heads from the Diagnostics menu.
4. How do I open the case?
The plastic case under the monitor has two sections. Different screws release
the plastic case or only the top (the part above the keyboard storage area).
Read the following two paragraphs before removing anything other than the first
step: unplug everything from the back. (Oh, yeah: "No user serviceable parts
inside") During reassembly be particularly careful with disk cables in rear.
Six vertically-mounted screws hold the top of the plastic case to the bottom of
the plastic case. When removing the top of the plastic case, there are three
plastic hook-and-tab catches in the front of the machine. The top of the case
must be moved outward slightly (usually with a screwdriver) along the joint to
the right of the floppy drive in order to release the catches. This exposes
only the drives and power supply.
When removing the plastic case from the metal base, 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 and the two horizontally-mounted screws in the rear of the machine.
Removing the entire plastic case exposes all metal-mounted parts other than the
monitor.
To open the top of the metal shield pan, remove three screws in top of front.
Disconnect monitor cable on left and ribbon connector to power supply on right.
Release latch on each side and lift forward, then up. This exposes the
motherboard.
5. How can I put in a larger disk drive?
Upgrading from a 10 or 20MB to a 40 or 67MB drive may require a 3B1 power
supply and a 3B1 full-height drive case top, dependent upon drive
characteristics.
Using more than 67MB requires either an SCSI board or making hardware changes
to the motherboard.
6. What is THE STORE! and how do I use it?
THE STORE! is a computer with UNIX-PC software which can be downloaded to your
machine via uucp. It is operated by AT&T. THE STORE! is absolutely
unsupported, but the catalog is still on-line and there are some neat things
available.
How to get there:
1. The machine is named the shop with login shop in your L.sys(Systems)
file. The phone number is (201) 957-4646. There is no password on this
uucico-only login. 1200bps is supported as well as 2400bps (I think,
Try it.)
2. Once you've built this entry, do the following:
uucp shop!/store/STOREROOM/CATALOG+IN /usr/spool/uucppublic/CATALOG+IN
This in an installable package. Do it and enjoy.
WARNING: The CATALOG+IN file is huge and will cost you plenty bucks to
capture if you are a long ways away from New Jersey.
7. The On-Board Modem does not work with some other modems.
The OBM creates tones which confuse some MNP modems and the Telebit Trailblazer.
The tones cannot be altered, but often a system which cannot call the UNIX PC
OBM can be called by the UNIX PC OBM. The Telebit modems can be set to call the
OBM.
8. What is the operating system?
The operating system is based on UNIX System V revision 1, with Sys Vr2 and
other extensions. The most recent version is 3.51, with a 3.51a "fix" disk
available.
Changes in 3.51a:
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.
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: lockfiles not being
removed, vt100 enter key mapping incorrect, slow performance when using 513 or
vt100 emulation
The UNIX(r) PC 3.51a Custom Kernel (/UNIX3.51a) has fixes for: tty driver does
not return null character on break, break sent over modem freezes serial port,
lp driver truncates lines to 132 chararters
Kmap (/usr/lib/ua/kmap.610) corrects the misspelling of RollDn in the kmap file
for the 610 terminal.
Ksh (/bin/ksh) fixes: 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: 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: uucico hangs at call completion,
uucico turns modem speaker on, time stamps incorrect in LOGFILE
9. What third-party hardware is available?
Digital Data Systems, Inc., Marietta, Georgia (404-425-5700)
42 and 62MB drives.
2MB RAM expansion board.
IDT Systems, Inc., Newark, Delaware (302-731-1583)
3B1 HCD Kit (kit to modify 3B1 motherboard for larger disk).
Motherboard RAM upgrade from 1/2MB to 2MB.
2MB RAM Expansion board (available soon).
Bus Station (TM) SCSI adapter board ("project shelved").
Vartech, Lisle, IL (312-810-1777)
EIA (RS-232) "Combo" boards.
10. How can I make a full-screen window?
The following entry in the file "Office" in your home directory creates a
full-screen window with a UNIX shell. From a UNIX shell, instead use the
`windy` tool.
Name=Big-Screen UNIX
Expert
Default = Run
Run=SH -wd
Help=EXEC -d /usr/bin/uahelp -h /usr/lib/ua/ua.hlp -t "UNIX System"
Prompt = Press Ctrl-D to exit
11. Some AT&T serial boards do not work right. How are they identified?
The EIA boards (or EIA/RAM) in question are anything RELEASE F or higher. Check
the revision release letter on the board, usually enscribed on the circuit side
of the PC board on either edge. If it is letter F,G,H,I,...Z call AT&T at (800)
922-0354 (HOTLINE) and tell them you need the serial controller chip for the
AT&T UNIX PC EIA boards that they are replacing. They will send you a Zilog
8530 SCC chip. You will replace the 40 pin chip in it's socket and you'll be
set!
Contributors and References:
1: BYTE, Vol 10 no 5 (May 1985)
1: gil at limbic (Gil Kloepfer Jr.)
2,8,9,11: lenny at icus.UUCP (Lenny Tropiano)
3: "Shutdown" (page 3-95) in AT&T UNIX PC Owner's Manual
6: Joe L. Wood
8: rjg at sialis.mn.org (Robert J. Granvin)
8: AT&T 3.51a fix disk
--
Scot E. Wilcoxon sewilco at DataPg.MN.ORG {amdahl|hpda}!bungia!datapg!sewilco
Data Progress UNIX masts & rigging +1 612-825-2607
I'm just reversing entropy while waiting for the Big Crunch.
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