Odd VT100 question

From: Jerome Fine <jhfine_at_idirect.com>
Date: Fri Sep 28 19:55:31 2001

>Bill Pechter wrote:

> > Jerome Fine replies:
> > Why did DEC not make such low cost systems available for hobby
> > users?
> Bad management, no vision. The VT103 supply barely was enough
> for the 11/23 and was designed to handle stuff like hasp
> printing at IBM shops via RSX11-S downloaded apps with network booting.

Jerome Fine replies:

I think the manual says 16 A on the 5 Volts and much less on the 12 volts.
About 10 years ago, just for fun, I put in a quad 11/73, 4 MBytes of
non-DEC memory, a quad ESDI controller and a DHV11. I only ran it
for 15 minutes since that was probably stretching the power supply.
As I said, the ESDI hard drives were connected to a cable out the back
and ran on their own PC power supply, each with its own fan.

Prior to that it had been running with a dual 11/73, DLV11-J, 1/2 MByte
of memory and a 3rd party MFM controller that did MSCP - a total
of 2 1/2 slots. the hard happened to be an RD53 and it was under the

Obviously, the backplane had been upgraded from 18-bits to 22-bits
by the addition of 4 wires soldered to the backplane - 8 spots for each.

I think I acquired my first VT103 around 1989. Were the VT103s
first produced around 1980? Since all four quad slots were ABAB,
that allowed up to 8 dual boards. Which was almost equal to the
BA11 with 9 slots - all ABCD.

As for DEC, they seemed to be afraid of producing something that was
was both small and inexpensive. Essentially, the VT103 was a small
but complete PDP-11 that could run any of the operating systems
quite well, especially when the backplane was upgraded to 22-bits.
Did DEC ever sell any that they had upgraded to use 22 bits

Sincerely yours,

Jerome Fine
Received on Fri Sep 28 2001 - 19:55:31 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:34:26 BST