20 Aug
2010
20 Aug
'10
11:04 p.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of allison
Sent: Friday, August 20, 2010 2:00 PM
To: On-Topic Posts Only
Subject: Re: Origin of the term minicomputer (was Re: PDP-1 as
minicomputer
[snip]
The PDP8 was a instruction and mostly compatible but improved
follow on to the all transistor PDP-5 (1963) but much larger than
the first version of the PDP-8 by a factor of three racks. Note the
PDP-5 was almost as large as the PDP1 but was aimed at lower
cost to buy and use.
[snip]
Allison
One thing I've read is that the PDP-5 was not originally intended to be a general
purpose computer, but rather sort of an I/O coprocessor for the PDP-4. Do you have any
direct knowledge of that assertion?
I also think it's interesting that the program counter in the -5 was originally
location 0 of core memory, requiring a minimum of a read-modify-write cycle for each and
every instruction.... -- Ian