Article View: mod.computers.68k
Article #186Re: Small systems & MMU's
From: bandy
Date: Tue, 24 Feb 1987 17:56
Date: Tue, 24 Feb 1987 17:56
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>>> I, too, had a small system, but I learned that a UNIX type system, with
>>> [...] Vmem [...] unleashes power one couldn't dream of before.
>
>Gee, the biggest, fastest Unix box I can get to (both legitimately and
>otherwise) doesn't have VM. Their attitude is "Real memory for real
>performance." Maybe the hardware designers know something you don't?
Right, while it doesn't have vm, it does have memory management - upper
and lower bounds registers, if I remember properly. It has just enough
memory management to keep people separated from each other.
>There's a place for everything. Given a 68K based system, I'd rather
>not have virtual memory - just give me 16Meg of real, and forget the
>virtual.
Right. If you don't have applications that run in more memory *than you
can afford*, then you don't need vm (aside from the fact that with it you
can cut down your swapping). Now, I can't afford to put together more
than 256k worth of ram (I have to start haunting the surplus shops and
try to find some *cheap* ram) in my system and I'd really rather not try
to swap to a slow device (or use the "parent and child run in the same
address space" approach -- *slow*!), so it seems that for me, putting an
mmu of any sort into my system (even a 68451) is a win -- it makes unix
run much cleaner and it allows me to make the best of the small system
that I have.
andy
--
Andrew Scott Beals, {lll-crg,decwrl,allegra}!amdcad!bandy +1 408 749 3683
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!utgpu!water!watnot!watmath!clyde!rutgers!mit-eddie!genrad!decvax!ucbvax!amdcad.UUCP!bandy From: bandy@amdcad.UUCP.UUCP Newsgroups: mod.computers.68k Subject: Re: Small systems & MMU's Message-ID: <8702241756.AA22311@amdcad.AMD.COM> Date: Tue, 24-Feb-87 12:56:53 EST Article-I.D.: amdcad.8702241756.AA22311 Posted: Tue Feb 24 12:56:53 1987 Date-Received: Fri, 27-Feb-87 04:36:48 EST References: <8702240242.AA14178@violet.berkeley.edu> Sender: daemon@ucbvax.BERKELEY.EDU Distribution: world Organization: Advanced Micro Devices, Sunnyvale, California Lines: 29 Approved: info-68k@ucbvax.berkeley.edu