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From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: unix and memory, sigh (was Re: What Happens If You Have > 9 Meg??
Message-ID: <18287@cbmvax.commodore.com>
Date: 29 Jan 91 22:50:21 GMT
References: <7016@crash.cts.com> <890@amix.commodore.com> <1991Jan24.014652.14960@kessner.denver.co.us> <1991Jan26.002917.21545@lavaca.uh.edu> <43339@ut-emx.uucp>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 34

In article <43339@ut-emx.uucp> amiga@ccwf.cc.utexas.edu (Paul) writes:
>The Amiga 3000 is capable of accessing 1.7 Gigabytes!!!! Not a limit you will
>excede soon.

More practically speaking, you get 18MB for the price of the memory chips, 
since that's what fits on the motherboard.  You never need to throw any away
if you're smart about expanding any C= base configuration.  On top of that,
you can add 8MB of Zorro II memory if you want it, but it's very slow in
comparison.  Theoretically, you can have 128MB of memory in the coprocessor
slot area and 1.75GB of memory in the Zorro III space, but that's not something
you're likely to find on store shelves tomorrow at lunch time.  

I cranked out a 32MB memory board for Zorro III in about a week, as part of an
article for last Spring's DevCon in Atlanta.  Not the best design in the world,
and with 80ns DRAM it's roughly 30% slower than normal burst-mode A3000 
motherboard memory.  Since I had four of there boards built, it is technically
possible today to expand one A3000 to 146MB of real memory, if you aren't 
concerned about room for Ethernet or TIGA display boards.  More practically
speaking, a commercial version of this board would probably be a somewhat 
better design, and could possibly manage 48MB-64MB of DRAM, depending on how
good the layout people are (eg, 64MB is a _tight_ squeeze for ZIP RAM and
Zorro III bus interface, not to mention the DRAM controller).  Using the
now-sampling 16Mbit chips, rather than the 4Mbit chips my board did, you could
put 192MB-256MB on a single board, with some effort.  And it would cost a
fortune.  

Of course, today, off the dealer's shelf, you can get 18MB plus that additional
8MB of 16 bit RAM into your A3000.


-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
	"What works for me might work for you"	-Jimmy Buffett