[Coco] Upgrading Coco 1 E to 64K without modifications to the main board.

Shaun Pow spow at ispac.com
Mon Nov 13 19:08:27 EST 2023


Very cool group - although i've never participated in an email only list 
type of group before so i am not sure if i am posting this correctly or 
what.  There seems to be no search of the threads and i did go through a 
few years looking for something similar to my query with little luck.

My son (14) and I recently bought a Coco 1 - E revision board.  Rom 
1.1.  It's been almost 40 yrs since i owned one - almost running into an 
old girlfriend :)  It's in fantastic shape and came with a bunch of extras.

I vaguely recall upgrading the RAM.  I am pretty sure i didn't solder 
anything (except for the mechanical keyboard i also added) but my memory 
could (is!)be faulty.  Anyway, i am wondering if there is a way to 
upgrade the 16K board to 64K without modifying anything on the main board.
I don't want to solder or cut leads - i just don't want to modify the 
original hardware.  I've seen a couple differing instructions for 
upgrading.  One involving just cutting capacitors and for some reason 
another also involving soldering wires.  This is from google searches 
and also looking at archived Color Computer and Rainbow magazines.

I am wondering if I can somehow bend the pins, solder, etc the 4164 
chips instead.  i have a lot of 4164 chips and could care less about 
accidentally damaging them.  Ironically have only 4 4116 chips in my old 
RAM box from my original coco.  not sure what happened to the other 4?

I am a bit over my head here but thought i might bend the 4164 pin (12V 
4116 pin - but ground on the 4164?) out of the socket and wire the two 
4164 pins (that were the +5V/-5V 4116 pins together - bending the -5V 
4116 pin and soldering it to the +5V 4164 pin)

I'm sure this has all been discussed in the past.  apologies if there is 
a search that i have missed.

One last thing - with my son buying a C64 last year - my guess is the 
build quality of the Coco 1 is immensely better.  From the problems he 
has had (memory and PSU) as well as hearing from other people.  Is this 
true?  Looking at the coco board vs the C64 seems to indicate that as 
well.  Also just bought an Atari 800XL (no experience with it now or in 
the past).  just building an collection - my son started with old 
nintendo consoles and now is interested in the old home computers.

thanks
Shaun (Ontario - Canada)


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