Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: ZIPS vs SIMS
Message-ID: <15728@cbmvax.commodore.com>
Date: 8 Nov 90 18:50:08 GMT
References: <13754@sdcc6.ucsd.edu>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 32

In article <13754@sdcc6.ucsd.edu> rblewitt@sdcc6.ucsd.edu (Richard Blewitt) writes:

>What is the advantage of using ZIPS as apposed to SIMS for the 
>memory in the 3000.  There must be some, because ZIPS cost more, and
>Commodores philosophy is not to spend more then they have to.

They don't cost Commodore more.  They may cost you more in small numbers,
simply because they're a low volume item at the local computer store relative
to SIMMs.

The main reasons we used them in the A3000:

	- High density:  They take up 1/2 the space that DIPS occupy.  Stand-up
	  SIMMs are roughly as dense, lean-over SIMMs aren't.

	- Upward compatibility: The 256K x 4 and 1M x 4 pinouts were 
	  compatible.  SIMMs can offer upward compatibility too, since pinout
	  changes can be resolved on the SIMM PCB.  DIPs weren't upward
	  compatible, since no one had announced a 0.300" DIP in the 1M x 4
	  density.

	- Height: 1M x 4 ZIPs fit in the space under the Coprocessor slot.
	  DIPs would have too.  SIMMs are too tall, and there was nothing
	  practical would could have done to use them in a machine as tightly
	  packed as the 3000 -- the memory array had to go where it did.

>                                               Rick Blewitt

-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
	Standing on the shoulders of giants leaves me cold	-REM