out-of-mainstream minis

Chuck Guzis cclist at sydex.com
Sat Jul 4 15:04:27 CDT 2015

On 07/04/2015 11:16 AM, Diane Bruce wrote:

> Sure, and the information they did push on the stack when they finally
> added instruction continuation was pretty hefty. 68010 had that with
> limited addressing (Which the MAC (ab)used).

I recall that I'd suggested to the guy at WESCON that a programmable 
trap for user-mode instructions would be most valuable.  The 
instructions that raised Cain with virtual memory implementations could 
be implemented with other, simpler, instructions--if only they could be 
trapped before issue--and emulated by a bit of supervisor code.

He admitted that it was a good idea, but that the 68010 design was 
already being tested, so it was unlikely to see my idea done.

Of course, today, with very few people programming in much at a lower 
level than "C", the obvious solution would be never to generate the 
problem instructions.


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