8-bitters and multi-whatever

Allison ajp166 at bellatlantic.net
Tue Sep 11 06:50:14 CDT 2007


>
>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:
>> >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.
>
>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.  

>> >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 know of ARCnet,  went to a short seminar on that once at a trade show,  and 
>in fact even have a couple of ISA cards around here someplace,  though I 
>don't forsee me ever using them.

ARCnet and most of the 'nets were in the price range of a hard disk then.
Also the whole idea of networking was new.  For example in 1982 the two 
largest networks I knew of were DEC (internal) and Dupont(internal) and 
they were around 50 nodes!

There were a few simple schemes but excluding myself how many hobbiests 
back then had two or more systems?

>> >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.
>
>What does that take on the software side of things?

Not a whole lot, CPnet could be used but it was easy enough to use plain 
vanilla CP/M2.2 and add your own BIOS drivers for "networked functions".
defineatly home grown.


>> >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.
>
>Nope.  It's just my particular fascination these days.  And probably a lot 
>easier to deal with than lots of big iron.  :-)
>
>> >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?
>
>Just that I'd like to see some stuff that isn't oriented that way.  You have a 
>SBC,  you obviously need some way to talk to it,  but the standard "console" 
>stuff gets a little old,  I probably don't want to hook a printer up to it,  
>and may not even want a disk drive of any sort,  depending on what I wanna do 
>with it.  I'm up for exploring some alternative approaches to doing things.  
>Unfortunately the embedded stuff that's out there doesn't satisfy too often,  
>the design being too specific to the app,  source code not available,  etc.  
>I'm thinking that it should be possible to have some sort of a more 
>generalized framework to hang things on,  and then you could optimize it for 
>specific uses,  or expand it in different directions.  Even from the earliest 
>days "personal" computers all seemed to take pretty much the same approach to 
>things...

Well by hook or by grook the average PC still has a serial port, some have two
or atleast a USB port for a USB to serial.  It's not that hard to write software
to use that serial as a access from the SBC for things like a remote printer
or disk and people have and are doing it. It's not "networking" in the full 
blown sense but none of the IO of a SBC is required to direct connection 
to a printer or terminal (ignoring rom based stuff).

>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




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