Newsgroups: comp.arch
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Blitters and design philosophy
Message-ID: <1988Aug1.062659.25971@utzoo.uucp>
Organization: U of Toronto Zoology
References: <5254@june.cs.washington.edu> <76700032@p.cs.uiuc.edu> <480@m3.mfci.UUCP> <401@ma.diab.se>
Date: Mon, 1 Aug 88 06:26:59 GMT

In article <401@ma.diab.se> pf@ma.UUCP (Per Fogelstr|m) writes:
>... Do that with the CPU. Even with external hardware the CPU will not
>be able to generate the addresses fast enough. (You have to generate a new
>address each 50-100ns).

Have you, pray tell, seen the manual for the AMD 29000?  I have.  Please
read it before proclaiming this performance to be beyond that of a CPU.
(The 29000 is available today, although it's not yet cheap.)  Or the
manual of any modern RISC-based machine, for that matter.

To sort of paraphrase a comment the Mips people have made about memory:
think twice before building specialized hardware to do something a
general-purpose CPU can do, because many people are putting enormous
resources into making the g-p CPUs better and faster, and they may well
catch up with you -- probably sooner than you think.  Exploiting mass-
market products can work better than trying to compete with them.
-- 
MSDOS is not dead, it just     |     Henry Spencer at U of Toronto Zoology
smells that way.               | uunet!mnetor!utzoo!henry henry@zoo.toronto.edu