[Coco] CoCo 1 'E' board memory upgrade

[Brian Blake]

Greetings CoConutz!

A while back, I picked up an E board CoCo 1, with what appears to be a
Radio Shack 32k upgrade. The original CoCo 1 case was fragged in shipping,
so it sat in the corner of my room until recently when I had time (due to a
broken leg) to work on it.

My plan was to upgrade to 64k, after transferring the motherboard into a
TDP100 case I from Tony Padroza even longer ago. That is pretty much done,
as can be seen in the images below:

https://cmtekwerx.com/transplant.jpg

https://cmtekwerx.com/testing.jpg


Where I'm having issues at is combining the Radio Shack 32k upgrade, with
the instructions from the May '84 Rainbow:

The work previously done: https://cmtekwerx.com/coco1-pcb.jpg

The instructions from Rainbow: https://cmtekwerx.com/rainbow-upgrade.jpg


I'm  pretty sure the upgrade is the Radio Shack 32k upgrade, with the
following mods done (see coco1-pcb image llnked above):

U29 pin 1 to U11 Pin 5, and the connections between U4 & U8; U29 Pin 2 to
pin 8; and U29 pin 3 to U8 pin 21.

This is where things get fuzzy - fresh 4164's and the 64k addressing
modification per the May '84 Rainbow, and noticed U29 pin 1 is connected to
U11 pin 5.
The article states U29 pin 4 should be connected to U11 pin 5. I'm guessing
this is in addition to the wire that's already running from U29 pin 1? Or
should that be removed?

A little education and clarity would be greatly appreciated!



Best regards,

Brian

-- 
Ohioan by birth, Mainer by the grace of U-Haul and a short-lived job...
--------
Sarcasm is the body's natural defense to stupidity.