11 Sep
2007
11 Sep
'07
4:50 a.m.
Subject: Re: 8-bitters and multi-whatever
From: "Roy J. Tellason" <rtellason at verizon.net>
Date: Mon, 10 Sep 2007 16:24:01 -0400
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
On Sunday 09 September 2007 16:04, Allison wrote:
I remember seeing that in some sales literature and it always did strike me as
being more spendy than I wanted or could afford to get into. :-)
It cost more because it was industrial strength, larger boards, regulated power
and so on.
A while
back I *almost* got a hold of one of those "z80 network in a box"
systems, it wasn't S-100 but something else I can't recall, I think
that's the one I have the book on, but I never did snag it.
Multibus, very nice bus and expensive cards. I have a few multibus cards.
Intel used it in their MDS800 and a few otehrs as well. Unfortunately instead of RS232 Televideo has something
else going there
(RS422?), not easy to interface too, and they distribute their "network"
out amongst what other Televideo boxes you have, which in my case is
none. I guess with an S-100-based system you could always add more cards,
and somehow or other make it work.
And speaking of the networking aspect of it, do any of you guys know how
they did it? I recall one time getting a glimpse of some system or other
that was S-100 but also had a set of connectors at thet op of each card,
which is what they used for their inter-processor linking rather than
trying to push it through the bus. The reason for this is not apparent
to me.
Many ways to do it, using a commmon port or a pool of common memory for
in box networking and serial ports as well. There were also ARCnet, pre
Ethernet and even Ethernet. I've also seen some "CP/M networking"
stuff referred to that was supposed
to work through serial ports, which pretty many machines had, althogh
they appeared in at least one case to be using diodes to wire-OR RS232
signals, which doesn't strike me as too terribly robust. And what
software support there was for this wasn't real apparent.
That was a poor mans networking. Basically the serial ports were used as
CD/CSMA bus and there was some protocal like Ethernet but slower and could
use the usually common async chips. I have such a net going for my CP/M
crates and all. I dunno, I've just got this fascination for
assorted 8-bit parts talking
to each other through some smallish number of wires, I guess it's easier
to deal with than some of the big iron you guys handle regularly, which
I can't afford to go get never mind housing. And I've seen multiple
processors used in stuff already, as in some musical equipment that
passed "event information" from one chip to the next with only a couple
of pins, or the daisywheel printer that had _four_ 804x procesors in it
for different functions.
This is not a new thing. TurboDOS
is neat, and has some good design aspects in it, but there's
too much legacy stuff in there for being able to run CP/M software,
stuff I'd leave out if it were me and too much emphasis on the same old
Console / Printer / Disk Drives in the system, as opposed to something
different or unique. I found the same thing to be the case when I looked
at FORTH, too much of the usual stuff, and that was supposed to have
been used in some control applications? I must've missed something
there...
???? Whats the question or point? I realized in other messaging a while back that
it's been well over a year
since I fired up a soldering iron, and this is a bad thing. :-) And even
then, it was a matter of scrapping stuff, not building anything new and
interesting. I need to get out of that particular rut and get back to it,
or there's no point to all those parts I've been scrounging for decades.
Maybe one of these days I will...
When you do tell us about it. Seems these days I get to maybe one
of the major computer construction based projects maybe two per year.
But I split my time between RF projects and digital projects.
Allison
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin