home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The Don Maslin Archive
/
maslin_archive.zip
/
AARDVARK_Tape_Backups
/
maslin_c_d_3oct95
/
ddrive
/
sydex
/
intertec
/
compustr
< prev
next >
Wrap
Internet Message Format
|
1990-09-20
|
5KB
From simasd!nosc!CRDEC2.APGEA.ARMY.MIL!pvpullen Thu Sep 20 06:05:03 1990
Received: by simasd.UUCP (smail2.5)
id AA06672; 20 Sep 90 04:43:43 PDT (Thu)
Received: from CRDEC2.APGEA.ARMY.MIL by trout.nosc.mil (5.59/1.27)
id AA27298; Thu, 20 Sep 90 04:27:20 PDT
Date: Thu, 20 Sep 90 7:24:43 EDT
From: "Paul V. Pullen" <pvpullen@CRDEC2.APGEA.ARMY.MIL>
Ppath: pnet07!donm
To: simasd!pnet07!donm
Cc: pvpullen@CRDEC2.APGEA.ARMY.MIL
Subject: Intertec Compustars
Message-Id: <9009200724.aa25505@CRDEC2.APGEA.ARMY.MIL>
Don,
Intertec manufactured four versions of the Compustar computer. They were
equipped for setting up multi-user 'networks' using either a 10 megabyte or
80 megabyte hard drives. They are all equipped with the usual modem and
auxillary ports on the back panel, as well as two ~35 pin d-type connectors
that attached the systems to the hard drives. Each unit is equipped with an
additional board called a chaining adaptor that enables the units to 'chain'
together and use the common hard drive. It was a good idea for software, and
then had you use a floppy (?) for your data.
Intertec's design included the use of a hardware switch on the chaining adap-
tor that enabled the system to have a maximum of 255 different 'stations' on
the 'multi-user system'. Each station would have its own section parsed out
of the hard drive, an individual drive c: assigned to the terminal. If it
did not have an 'area' carved out of the hard drive, the system would not allow
the station on the network. We used a maximum of 4 stations at one time on our
network when it was operational. It seemed to work pretty well.
Intertec manufactured the following models in the Compustar line:
VPU-10 This model was a terminal only. It required its operating
system to be written to the system tracks of the hard drive.
There were no floppy drives on these terminals. I guess it
would be considered the system console.
VPU-20 This model contained either one or two (I never saw one of
these) Single sided disk drives. What little I know is from
an enhanced piece of software that formatted disks especially
for the systems 20,30, and 40. If I recall correctly, it uses
drive a: to format the disk, so I suspect that the VPU-20 only
had one disk drive.
VPU-30 This model comes (or came) in at least two versions. I have
samples of each, both personal and government owned. The
systems contained two DSDD disk drives, and could be booted
either in stand-alone mode (no hard drive) or in networked
mode.
VPU-40 This model contained the 96 tpi drives. I have never seen one.
I will check for ROM versions, but the easy way on the VPU-30 to tell the diff-
erence between them that I know is two fold. First, the power supply on the
non-enhanced VPU-30 is mounted on the bottom chassis. It is tied together with
the main circuit board by a flat cable that is made up of strips of 'aluminum
foil' in vynal jacket. It truely is a flat cable. This model of computer uses
Magnetic Periphals disk drives (NEVER use a Tandon Drive in this version. The
current draw of the Tandon will blow the power supply).
The smarter VPU-30 has its power supply mounted on the back of the disk drive
cage. It has a larger power supply and was stocked with Tandon TM100-2 disk
drives. It needs a different operating system than the non-enhanced. Another
difference is the real-time clock battery mounted on the upper right hand
corner of the main circuit board. The circuitry is different on the boards,
but both would maintain a clock in the upper right corner of the tube. The
enhanced would, like the present pc-clone, maintain the time even when turned
off. The enhanced version of the VPU-30 was equipped to maintain the time,
whether the system was off or on.
If I recall, the ROMS never had marks on the outside as to what their ROM
revision was. We had problems with this and the hard disk DSS-10's. I have
two personal DSS-10's with different ROMS in them. It is terrible to
re-initialize. By guess and by gosh I have re-initialized them, but you
have to play with the computers to find one that will talk to the disk drives.
This is a first run of information that you can store. I will assemble the
boot disks and get them out to you as soon as I can put them together.
Paul
----------------------------------
Paul Pullen
United States Army Chemical Research, Development and Engineering Center
pvpullen@crdec2.apgea.army.mil
(301) 671-2519 /(301) 671-4174
----------------------------------