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From: DYOUNG@USC-ISID.ARPA (C. David Young)
Newsgroups: net.micro.atari8
Subject: Re: 256k Upgrade/DOS 2.5 Modification
Message-ID: <8604041854.AA10298@ucbvax.berkeley.edu>
Date: Fri, 4-Apr-86 13:33:48 EST
Article-I.D.: ucbvax.8604041854.AA10298
Posted: Fri Apr  4 13:33:48 1986
Date-Received: Tue, 8-Apr-86 05:06:07 EST
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I would like to make a couple of points of general interest. First, CDY does
not manufacture its own 256K upgrade. It buys them from Newell and resells
them like any distributor.

Second, I have heard from people about at least 2 problems with the RAMBO
256K upgrade. First, it does not support ANTIC at all. If you put your
screen memory down in the bank area and flip banks your screen goes
away. The Newell version has logic to keep ANTIC in main memory even
when the CPU is switching banks and it has a switch option to allow
ANTIC to follow banked memory. As an example as to why this is important,
I am in the process of converting AtariWriter Plus to work 80 columns.
The only room left to put the 80 column screen was in one of the banks.
This conversion has no chance of working with the Rambo board. The second
problem with the Rambo board is that it does not protect main memory
when banking is occurring. With this board it is possible, for example, to
access zero page or the stack via one of the (illegal) banks in the
$4000-$7FFF range. With the Newell board this dangerous situation is not
possible.

On the positive side, it is nice that the Rambo board will install in a
1200XL. Newell will only do this in house.

David Young
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