On 2016-05-25 7:06 AM, Dave Wade wrote:
paths.
Do you mean the 360/20? On the topic, were the 20 and 40 the only members
of System 360 to use TROS?
I remember picking up the programming manual for a Model 20 and realizing
that I'd essentially have to re-learn programming. 16 bit registers, stripped-
down instruction set, no I/O channels, "substitute"
instructions for regular 360 fare.
A really strange thing was that the 1130 came out *after* the 360/20.
I am not sure why IBM produced an in-compatible machine so soon after 360 was
announced, but it was sold in a completely different way to a new and emerging
market.
The book cited earlier by Paul Berger, "IBM's 360 and Early 370
Systems"[1], might give some of the reasoning here. It does have a lot
of discussion about how the competing lines were resolved. I just
finished reading it but I don't recall whether it addresses this
specific point.
--Toby
[1] https://mitpress.mit.edu/books/ibms-360-and-early-370-systems
It was billed as the cheapest computer IBM had ever offered. The announcement
letter here:-
https://www-03.ibm.com/ibm/history/exhibits/1130/1130_initial.html
is dated almost exactly one month before DEC announced the PDP-8 and I am sure targets
the same markets DEC did. You just wonder if IBM had spies in DEC, or more likely they
both spotted a marketing opportunity. It is also interesting to note a
"typical" configuration was priced at almost twice that of the PDP-8..
(assuming Wikipedia is right)
https://en.wikipedia.org/wiki/PDP-8
I don't have any links but I know in the UK IBM1130's were used on ships by the
Institute of Oceanographic Sciences but I can't find any reference to that
on-line. I was told that they had great trouble getting the IBM engineers who
worked on it that a suite was not suitable dress for a small research vessel.
Dave
G4UGM
--Chuck
Dave
G4UGM
