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From: jgallego@pnet01.cts.com (Jose Gallego)
Newsgroups: comp.sys.amiga.hardware
Subject: A500 Internal 1Meg
Message-ID: <1991May22.181607.22657@crash.cts.com>
Date: 22 May 91 18:16:07 GMT
Article-I.D.: crash.1991May22.181607.22657
Organization: People-Net [pnet01], El Cajon CA
Lines: 33

This is the result of the comments I received regarding the modification of
the A500 with Rev. 6A board:

1. You can add 4 extra memory chips to those empty sockets.  You can do this
by either soldering the chip to the motherboard or solder chip sockets and
then plug in the chips.

2. You need to cut the trace on jumper JP2.  This is locate to the left of the
68000 around the middle.  This jumper is located between the 68000 and the ROM
(U6).

3. You need to solder the trace in jumper JP2 to the middle to the bottom. 
This change (step 2 and 3) selects your A501-type memory expansion to be used
as chip ram.

4. Find jumper JP7A, locate near the A501 memory expansion and cut the trace. 

This "should" work.  I have not yet tried it.  Will this leave me with 1Meg of
chip ram and 512K of fast ram????

One final comment that I received:  THIS MODIFICATION IS NOT APPROVED BY
COMMODORE AND VOIDS YOUR WARRANTY... (neither do I, since I haven't tried it).
 
I am not sure what does removing the JP7A does, is this suppose to disable the
A501?
 
Thanks to those that answer my question,
Jose

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