Path: utzoo!attcan!uunet!mcsun!hp4nl!philapd!idcapd!wilko
From: wilko@idca.tds.PHILIPS.nl (W.C. Bulte)
Newsgroups: comp.sys.atari.st.tech
Subject: Re: Upgrading Mega 2 to 4.
Message-ID: <902@idcapd.idca.tds.philips.nl>
Date: 1 Oct 90 15:41:40 GMT
References: <1599@kielo.uta.fi>
Organization: Philips Information Systems, Apeldoorn, The Netherlands
Lines: 29

In article <1599@kielo.uta.fi> jackin@vehka.uta.fi (Markku M{enp{{) writes:
>I have a Mega ST 2 which I am planning to update to 4 MB.
>
>I have now 16 empty sockets available, but putting 80ns
>chips didn't work. It was quite expectable original chips
>being 150ns.
>
>Do 120ns chips work or do I need 150ns (rare in 1MB chips) ?
>Is there anything else to do apart putting chips in and 
>soldering capasitators (as is done in original 2 MB) ?
>Markku M{enp{{ 
>email : jackin@vehka.uta.fi
>phone : 358 31 561 575 (in Finland (931) 561 575)

First of all, I dont't see any reason why 80ns chips shouldn't work. However,
you might have a few resistors missing for the second DRAM bank. These resistors
are put in series with CAS and RAS lines (and R/W ??) connected to the MMU chip.
Some motherboards have them installed, even on Mega 2 boards, but some don't.
See if you can find them..

If you want to know what speed your old chips are, please mail me the type# 
I'll see if I can find them in the databooks.

Good luck, 
_     ______________________________________________________________________
 |   / o / /  _   Wilko Bulte   Domain: wilko@idca.tds.philips.nl
 |/|/ / / /( (_)                uucp  : [mcsun,hp4nl]!philapd!wilko
* Philips Information Systems Nederland   phone:  055-432372 fax: 055-432103
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