Make LispM code FREE (fwd)

P. T. Withington
Wed, 1 Apr 1998 14:48:47 -0500

On 3/31/98 23:41, Chris Hanson wrote:

>At 10:05 PM -0600 3/31/98, Chris Bitmead wrote:
>>The MIT lisp code would surely be interesting, but I really doubt
>>it is going to be much more than a curiousity rather than the
>>base for a new LispOS.
>That all depends how hard it would be to write an emulator for the hardware
>it ran on... :)

Can't be much harder than JVM.  That's what Symbolics did to make "Open 
Genera" -- it is a LispM emulator that runs on Alphas.  On a top of the 
line Alpha, it runs many times faster than the custom hardware ever did.  
(Another way of thinking about it:  the Alpha chip is the micro engine 
and the emulator is the microcode.  One reason the emulator runs so fast 
on the Alpha is that we were very careful to fit the "microcode" and 
"engine" into the Alpha's on-chip instruction and data caches.)

OTOH, the portable C prototype of the emulator ran like a dog...