Path: utzoo!attcan!uunet!munnari.oz.au!bunyip!uqvax.decnet.uq.oz!ccgavin
From: ccgavin@uqvax.decnet.uq.oz
Newsgroups: comp.sys.amiga.hardware
Subject: 2M chip ram for A500 rev 6 boards????
Message-ID: <1990Aug14.230453.14700@uqvax.decnet.uq.oz>
Date: 14 Aug 90 13:04:52 GMT
References: <3223@rwthinf.UUCP> <13645@cbmvax.commodore.com>
Distribution: comp
Organization: University Of Queensland
Lines: 30


In article <13645@cbmvax.commodore.com>, daveh@cbmvax.commodore.com (Dave Haynie) writes:
> In article <3223@rwthinf.UUCP> stefanb@cip-s02.informatik.rwth-aachen.de (Stefan Becker) writes:
> 
>>Is it possible to upgrade the A3000 to 4MB Fast-RAM with 1Mx4 DIP(!!) chips,
>>which replace the existing 256Kx4 DIP chips in the first bank?
> 
> Two problems here.  First of all, I'm not certain that the DIP bank was
> wired for the extra address line necessary for the 1Mx4 parts, though there
> is a good chance it was.  The second problem is the one to overcome -- find
> a source of 1Mx4 DIPs in 0.300" packages.  At least back when we had to make
> this kind of decision, only one company had announced a 1Mx4 DIP part, at it
> came in a 0.400" package, which of course isn't physically compatible with
> the thinner DIPs we're using, even if the pinout is the same.  ZIPs aren't a
> problem, since they grow vertically rather than horizontally.  Anyway, if
> 1Mx4 0.300" DIPs start to show up, I can easily check to see about whether
> they work in the A3000's Fast-Bus DIP sockets.

	Is the revision 6 A500 mainboard wired for the extra address line to
support 1Mx4 DIPS. Also is there any modification needed other than replacing
the current 256kx4 DIPS with the 1Mx4s to produce a 2M chip ram A500, as the
Agnus chip in the rev 6 boards is supposed to be the same as in the A3000 that
supports 2M chip ram.

Thanks in advance,
Gavin.............
-- 
Internet: ccgavin@uqvax.decnet.uq.oz.au         Phone: +61 7 377 3025
  Postal: Gavin Stone-Tolcher, Prentice Computer Centre
          Queensland University, St Lucia, QLD Australia 4067.