[Coco] CoCo 1 upgrade from 32k to 64k - Help

[Kip Koon]

Hi Glen,
Like you I found a CoCo 1 exactly like my original CoCo 1 I had 35+ years ago several years back.  This CoCo 1 has an "F" board which has a board number that starts with 2850... which means that all that is necessary to upgrade to 64KB of dynamic ram is to move a few jumpers and change out the DRAM chips.  Unfortunately, since I have never had a CoCo 1 with an "E" board, I can't help you.  I wish I could.  I'm sure someone will speak up.  Take care my friend.  


Kip Koon
computerdoc at sc.rr.com
http://www.cocopedia.com/wiki/index.php/User:Computerdoc

-----Original Message-----
From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Glen Hewlett
Sent: Monday, May 01, 2017 6:50 PM
To: CoCoList for Color Computer Enthusiasts
Subject: [Coco] CoCo 1 upgrade from 32k to 64k - Help

Hi All,

At the CoCo Fest I won an auction for an original CoCo 1 that was identical to first CoCo I ever owned.  It currently has 32k and it looks like it was a Radio shack upgrade since it also has the 32k badge on top.  I was testing to see if it was actually a 64k CoCo but when I ran the program to copy the ROMs to RAM and leave it in all RAM mode the program runs but I still can’t change any bytes where the ROMs are loaded.  So it still seems to be setup in hardware as a 32k CoCo.  One weird thing though is that if I do a Poke &HFFDF,0 it locks up the computer.  But If I try the same Poke &HFFDF,0 after running the program that copies the ROMS to RAM the computer doesn’t lock up but again I can’t change any byte above $8000.  I also tried the 64k game SailorMan and it fails to start.  I’m pretty sure it’s not a 64k CoCo 1.

I found a old site that was found in the internet archive the site was called Paul D's CoCo Hardware Page http://www.oocities.org/theother_bob/PaulDpages/hardware.html <http://www.oocities.org/theother_bob/PaulDpages/hardware.html>

It gives details about upgrading a Model E board CoCo 1 to 32k which I’ve followed and it looks like it’s already done on my Model E board.  At the end of the article it says:

"You should have 32K. For the 64K mod of this board, e-mail me to request it.”

Does anyone have the instructions for modifying a Model E board 32k CoCo 1 to 64k?

Any help is appreciated,
Glen

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