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From: sysmgr@KING.ENG.UMD.EDU (Doug Mohney)
Newsgroups: comp.arch
Subject: Re: processor for graphics terminal [was: PC/AT clones with RISC cpu]
Message-ID: <0093F295.10626840@KING.ENG.UMD.EDU>
Date: 3 Nov 90 18:06:01 GMT
References: <2081@aber-cs.UUCP> <0093F0E4.0B02A980@KING.ENG.UMD.EDU> <1990Nov2.000650.18866@jarvis.csri.toronto.edu> <0093F1A8.A28E4920@KING.ENG.UMD.EDU>,<1990Nov3.052952.1786@zoo.toronto.edu>
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Reply-To: sysmgr@KING.ENG.UMD.EDU (Doug Mohney)
Organization: The U. of MD, CP, CAD lab
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In article <1990Nov3.052952.1786@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes:
>In article <0093F1A8.A28E4920@KING.ENG.UMD.EDU> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes:
>>Doesn't count :-) PC compatability (for better or worse) and decent X-term
>>capability would be more better...
>
>Some people would consider neither a virtue. :-) 

Well, neither is the United States Congress, but we have to work with the
systems which are installed, eh? ;-)

> Both are de-facto standards
>that are hideously ugly and do terrible things to your system design if you
>enshrine them as fundamental goals.  (Retaining the potential for them, on
>the other hand, is easy:  any fast CPU with a large address space can
>emulate the early Intel processors at higher speed than Intel chips, and
>X is not difficult to port to a sane machine with a clean frame buffer.)

People will want X-terms and people will want PC-compatability. It is probably
easier to build a PC with 1024 x 768 monitor, and be able to drop in a couple
of bootstrap ROM which access your (built-in) Ethernet to load up the
X-software.

Of course, you could insist upon Token Ring as well, but I'm hoping it will go
away.  

I wouldn't do this with anything less than a '386; you can keep the
"earlier" Intel processors. Since AMD and others are coming out with '386
clones, the chip count would be pretty small.

>>...use RISC processor and stick in Soft-PC in ROMs...
>
>A small practical difficulty with this approach is that Soft PC is licensed
>software.  It also does a less than wonderful job of emulation, as our
>department is finding out on a bunch of DEC RISC workstations for undergrad
>teaching...

I said this was perverse. I didn't say it was optimized. I noted it would
require some hacking to get it running properly.

>>You might wanna look at how the SparcStation SLC was put together; I understand 
>>there are a couple of companies offering up glue chip-sets for Sparc.
>
>The two parts of this sentence are unrelated. :-)  I haven't seen details
>on the SLC, but Sun normally uses proprietary MMU designs that bear no
>relation to (e.g.) the "Sparc Reference MMU".  

So? I don't think Sun has patended the way they use board real estate. See how
they did things (Board in the back of the monitor <hm. What will all those
zappo evil EM rays coming out the back to do the chips in the long run?>, small
configuration). Go get the commercial Glue chips and go to town.

			Doug