8-bitters and multi-whatever

Chuck Guzis cclist at sydex.com
Thu Sep 13 17:59:59 CDT 2007


On 13 Sep 2007 at 17:36, Roy J. Tellason wrote:

> > And I'd also disqualify device-sharing, such as a MAC (multiple
> > access controller) between an I/O device and two computers.  Those go
> > WAY back...
> 
> I'm not familiar with such stuff.

Ah,  showing my age.  "Back in the day" you might have two otherwise 
independent mainframes and, say, two printers.  To have a system do 
nothing but wait for a print job to finish while only one of the 
printers was busy is a huge waste of resources.  A card punch might 
be an infrequenly used piece of equipment, so why have two?  Or a 
printer could be offline for maintenance, but why take the machine it 
was attached to down also?  Or, instead of having two banks of 8 tape 
drives for two machines, why not whittle that down to, say 12, and 
allow the drives to be shared?  IIRC, most vendors offered some sort 
of a MAC facility, even if it was a QSE.  CDC certainly did.

Of course, direct coupling of computers was also done, either via a 
special I/O device or even shared bulk core.  But we never called 
that "networking".

Cheers,
Chuck
 





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