Language-specific CPUs was Re: uIEC/SD == AWESOME!

Tony Duell ard at
Thu Jan 1 17:16:26 CST 2009

> Not once a few modifications have been done: RPL on HP calculators is
> essentially FORTH. (and to stay on-topic, I believe the Saturn
> Processor was designed specifically for RPL)

Was it? The first (production) machine to use the Saturn was the HP71B, 
which had BASIC in ROM. Maybe RPL was being considered at that time, but 
I am not certain of that.

Later versions of the Saturn did add some instructions to assist in RPL 
(the main one being PC=(A), basically a threading instruction). But I 
don't think Saturn machine code is particularly close to RPL even then.


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