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From: andrews@uicsrd.csrd.uiuc.edu
Newsgroups: comp.sys.mac
Subject: Re: Low-Cost Macintosh
Message-ID: <43100015@uicsrd.csrd.uiuc.edu>
Date: 3 Feb 90 10:34:26 GMT
References: <126900165@p.cs.uiuc.edu>
Lines: 53
Nf-ID: #R:p.cs.uiuc.edu:126900165:uicsrd.csrd.uiuc.edu:43100015:000:2383
Nf-From: uicsrd.csrd.uiuc.edu!andrews    Feb  1 17:41:00 1990



It will be difficult to make a low-cost mac using a 68030
for quite a long time.  The 68030 is much more expensive
than the 68000.  This will not change in the near future.

I think that the best chip to use for a low-cost mac is
a 16 MHz 68000.  This should be configured (if possible)
in the same manner that the 68000 is set up in the SE (i.e.
it runs 30% faster than the 68000 in the Plus).  Thus, such
a machine would be twice as fast as the SE, which is a
quite respectable speed.  Note that this should allow a 1-1
interleave (I think) for disk drives.  If so, then disk I/O would
be as fast as any '030 machine.

A low-cost mac should have two memory SIMM sockets to conserve
space and reduce cost.  The machine should ship with two 1-meg
SIMMs, resulting in 2 megabytes of memory, plenty for most
users.  The SIMMs should be upgradeable to 4-meg SIMMs, if
a user wants an 8-meg machine.  80 nanosecond 1-meg SIMMs are
becoming pretty cheap these days, as everybody knows.  Some
rough timing calculations I did make me believe that a 16
MHz 68000 (I don't have a spec for this speed) can run with
no wait states using 80 nanosecond parts (is this what the
portable does?).  A 68030 forces 4 SIMM sockets onto the
design (ignoring the dynamic bus sizing capability of the '030,
assuming it uses a similar system to the '020).

I have noticed a consistent bias among most writers on
the net towards:

1) Really fast CPUs.
2) Gobs of memory.
3) Huge disk drives.
4) Lots of bits of color.

This is probably because most net people are developing large programs, doing
large technical documents, using large spread sheets.  These people get
frustrated when the mac is slower than the Sun Sparcstation that they
use at their office.  There are many
people who don't need a super fast, super powerful machine.  These people
might prefer to have the list price of a machine reduced by, say, $500
by an attention to cost-cutting measures.  Yes, I know that Apple will
charge what the market will bear.  However, they cannot bring an '030
machine to market at a low price and keep their customary profit margin.
A 16 MHz '000 is fast enough for many users.  Someone who wants more
speed/power should buy an SE 30 or a IICX, not a low-cost mac.

Such a machine would not be able to enjoy all of the benefits of System
7.0, but such is life.

John Andrews
andrews@uicsrd.csrd.uiuc.edu