Date: Tue, 6 May 2008 23:03:50 +0100 (BST)
From: ard at p850ug1.demon.co.uk (Tony Duell)
Subject: Re: Interconnecting classic computers
To: cctalk at
Message-ID: <m1JtVGL-000J3OC at p850ug1>
Eric Smith wrote:
If we are going to discuss the WORST systems,
surely we can't leave out
the TRS80 casstte port system that RS came up with for classrooms!
Well, don't leave us in suspense. In what way was it done badly?
Was it unreliable? Did it fail to meet its design objectives?
Our school system had one, back in 1981.
There was a panel that was a mux/demux to 24-ish diskless model 3s. The
I thought the standard one was for 16 slaves to one host, but there's no
reason for that limit.
Sixteen student machines to one instructor station is correct.
I seem to rememebr the same hardware could be used
with Model 1s, Model 3s
and Cocos, but that the host and slaves had to e the same type of machine.
The first version, the Network 1, was limited to the 500 bps data rate of the Model One
interface. Model Ones could be combined with Model 3s and Model 4s, provided the users of
the newer machines specified the slow cassette data rate. The Network 2 supported the
1500 bps rate of the Model 3 and 4, the Color Computer line (including the MC-10) and the
Model 100/200. 3s and 4s could be mixed at will, all versions of the Color Computer line
could co-exist (except the MC-10 -- although the MC-10 used the same data format as the
other Color Computers, the BASIC ROM tokenized the keywords in its own unique way, so any
BASIC code exchanged would be garbage). The 100 and 200 could be intermixed. I recall
hearing about somebody using a Model 4 with its Mod 100 exchange utility getting that
combination to work, but I never tried it myself.
The Network 1 and 2 were actually rather clever devices for the era. Never gave me a bit
of trouble in my classrooms except when some of the students forgot to select the slow
speed on their Mod 3s (my first year as an RSCC instructor [starting 2 Nov 1980], the
classroom was full of Mod 3s, except of course for the instructor's system).
Ward Griffiths wdg3rd at
These histrionics were probably unnecessary, since there was no reason to think anybody
would be watching us with more than casual interest until I made my first move to follow
Buchanon's trail, in London. Still, somebody might check back this far later, and I
always feel that if you're going to play a part, you might as well play it all the
way, at least in public -- and it's hard to tell what's public and what isn't,
these electronic days.
Donald Hamilton, _The Devastators_, 1965