Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!hplabs!hp-pcd!hplsla!andyc
From: andyc@hplsla.HP.COM (Andy Cassino)
Newsgroups: comp.sys.atari.st
Subject: Re: Mega chips & drive questions
Message-ID: <5440088@hplsla.HP.COM>
Date: 29 Nov 89 20:03:51 GMT
References: <21653@brunix.UUCP>
Organization: HP Lake Stevens, WA
Lines: 36

mjv@iris.brown.edu (Marshall Vale) writes:

|I have several questions about chips in my Mega2. 
|
|I've been thinking about upgrading to TOS 1.4 and have read the messages
| about the weak power chips.

Based on my experience with the 6 chip ROM set in my Mega 2 (of an older
vintage), I heartily recommend changing those 74LS373's to 74AS373's if
you install a 6 chip set of ROMs. You might get by with the existing chips, 
and you might not. It's cheaper to have them put in during the ROM upgrade 
while things are apart than to do it later if it proves necessary. 

|
|I also noticed that there was a very tiny board on top of the 68000 with a 
|_SCST74LS74B1_ in it and a wire running to an unlabeled spot on the 
|board just above and to the left of the 68000.  Anyone know what its for?
| It seems like it was a rather last minute change and the glue job was
| very sloppy.

Hmmm, my Mega has a similar kludge except the extra chip is piggy-backed on
another small TTL chip. It's pretty sloppy, too. I assumed the dealer did
this in the ROM upgrade, maybe not, eh?


Disclaimer: The opinions expressed herein are those solely of the author,
            who has no pecuniary interest in the companies, products,
            or publications mentioned above.

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    % Andy Cassino                                                  %
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