Computing from 1976

David Bridgham dab at
Mon Jan 1 14:57:23 CST 2018

On 01/01/2018 03:33 PM, Noel Chiappa via cctalk wrote:

>     > From: Paul Koning
>     > The only asynchronous computer I can think of is the Dutch ARRA 1
> Isn't the KA10 basically asynchronous? (I know, it has a clock, but I'm
> not sure how much it is used for.)

This was my understanding, as well.

More recently there was the AMULET processors designed at the University
of Manchester.

One of the stories I read about the AMULET was that they wrote a little
program to blink an LED where the timing was determined by a busy loop. 
If they sat a hot cup of coffee on the processor, the light would blink
slower; a cup of ice water and it would blink faster.  If this were a
different group, I might suggest that this points the way to designing
computers that transition gracefully in Vinge's Zones of Thought but
I'll just leave that digression alone.

The Advances Processor Technologies group at the University of
Manchester also came up with the Balsa language, an HDL for asynchronous
design.  When I started working on my own PDP-10 implementation, I began
by writing it in Balsa, thinking I wanted it to be a follow-on to the
KA10.  I'm still interested in asynchronous design but I've let that
implementation go for the moment.

More information about the cctalk mailing list