Article View: comp.sys.mac
Article #45710Re: Low-Cost Macintosh
From: Joel B Levin
Date: Tue, 06 Feb 1990 19:58
Date: Tue, 06 Feb 1990 19:58
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1393 bytes
In article <131305@sun.Eng.Sun.COM> fiddler@concertina.Sun.COM (Steve Hix) writes:
|Any reason why a new, low-cost Mac couldn't be designed to take memory
|in integer multiples of SIMMs? Is there some reason that the Plus *had*
|to be designed to take them in pairs only? Or was it just easier to
|implement that way?
It would be a lot slower and need fancy circuitry. A SIMM only has 8
DRAM chips on it, so to do a 16-bit access (like the 68000 wants to
do) it would need to access each DRAM twice. With two SIMMs, you can
hit 16 DRAMs at once and get at all your bits in one go.
(And with the 68020/30/40 32-bit bus, you need to go 4 SIMMs at a time.)
/JBL
=
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or {...}!bbn!levin | bureau that morning. Wide-eyed and distraught, she
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!bbn!bbn.com!levin From: levin@bbn.com (Joel B Levin) Newsgroups: comp.sys.mac Subject: Re: Low-Cost Macintosh Message-ID: <51783@bbn.COM> Date: 6 Feb 90 19:58:36 GMT References: <126900165@p.cs.uiuc.edu> <43100015@uicsrd.csrd.uiuc.edu> <19157@dartvax.Dartmouth.EDU> <131305@sun.Eng.Sun.COM> Sender: news@bbn.COM Reply-To: levin@BBN.COM (Joel B Levin) Organization: BBN Communications Corporation Lines: 18