[Coco] CoCo 1 'E' board memory upgrade

[Brian Blake]

Alex - it wouldn't load or play Sailor Man - which does require 64k.

On Tue, Apr 16, 2024 at 10:18 AM Alex Evans via Coco <coco at maltedmedia.com>
wrote:

> Have you checked whether or not the machine has a good and accessible 64k
> rather than just 32k?
>
> On Tue, Apr 16, 2024 at 8:54 AM Brian Blake via Coco <coco at maltedmedia.com
> >
> wrote:
>
> > 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.
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > https://pairlist5.pair.net/mailman/listinfo/coco
> >
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco
>


-- 
Ohioan by birth, Floridian by the grace of U-Haul and a bad economy...
--------
Sarcasm is the body's natural defense to stupidity.