Newsgroups: comp.arch
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: processor for graphics terminal [was: PC/AT clones with RISC cpu]
Message-ID: <1990Nov3.052952.1786@zoo.toronto.edu>
Organization: U of Toronto Zoology
References: <2081@aber-cs.UUCP> <0093F0E4.0B02A980@KING.ENG.UMD.EDU> <1990Nov2.000650.18866@jarvis.csri.toronto.edu> <0093F1A8.A28E4920@KING.ENG.UMD.EDU>
Date: Sat, 3 Nov 90 05:29:52 GMT

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. :-)  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.)

>...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...

>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".  Worse, not only are they
proprietary but they are Top Secret, although apparently Sun has entirely
forgotten why, since they can't offer any rational reason for it when
asked.
-- 
"I don't *want* to be normal!"         | Henry Spencer at U of Toronto Zoology
"Not to worry."                        |  henry@zoo.toronto.edu   utzoo!henry