Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!adm!pcl%robots.oxford.ac.uk@cs.ucl.ac.uk
From: pcl%robots.oxford.ac.uk@cs.ucl.ac.uk (Paul Leyland)
Newsgroups: comp.unix.wizards
Subject: Re: multiple-machine executables for Suns?
Message-ID: <9015@brl-adm.ARPA>
Date: Wed, 26-Aug-87 12:07:34 EDT
Article-I.D.: brl-adm.9015
Posted: Wed Aug 26 12:07:34 1987
Date-Received: Fri, 28-Aug-87 05:15:12 EDT
Sender: news@brl-adm.ARPA
Lines: 43

In article <288@nuchat.UUCP>, steve@nuchat.UUCP (Steve Nuchia) writes:
> In article <12646@sol.hi.UUCP>, kurt@hi.UUCP (Kurt Zeilenga) writes:
> > But more seriously, if I was going to design an a.out format that could
> > "run" everywhere I would have the compilers, loaders, etc output a psuedo
> > code and then have the kernal interpet the code.  This will keep the
> > a.out small, but the will take FOREVER to execute. 
> 
> Has anyone done a simple stack machine that runs C programs
> reasonably well?
> 
>                                Is there enough interrest out
> ther to justify the experiment?  Anyone want to help?
 
The answer is yes.  I have microcoded a C machine.  The raw beast was
built round AMD2900 series bit-slices.  As the control store was in RAM,
I could also convert it to a Lispkit Lisp machine and a BCPL machine.

The C implementation was a double stack machine (one for scalars, return
addresses, etc; the other for aggregates) with machine instructions
for loading auto and static variables onto and off the appropriate
stack; function call and return;  arithmetic and logical operators;
case selection and so on.  Most C constructs compiled into a few
instructions.

The machine is still made, by High Level Hardware Limited of Oxford, UK,
but it is looking a bit old fashioned now.  Such copmputers *needn't* be
slow.  The Orion (for that is its name) has approximately the performance
of a VAX750 but was significantly cheaper, 30-50% of DEC's price, when
both were viable products.  I guess that it should be easy to double
the speed with today's technology but 4-5 times the performance would
be tricky and that still only gives you a half-way decent 68020
based machine or a poor to middling VAX.

If any one wants to help me make a fortune by coming in on the design,
manufacture and selling of an up-rated machine though, let me know 8-)

Paul Leyland	JANET: pcl@uk.ac.oxford.robots
		How you get to talk to JANET is your problem -
		why not give her a call?



----- End Forwarded Message -----