Sitenotice: 11/29/2018: The wiki is back. It turns out, some anti-virus product on my web server had an issue with the latest version of PHP. My server techs have resolved this issue, and things should be working again. During the investigation, I did restore to a backup from September. There is a chance that any changes done since then were lost, but I do not recall any edits. --OS-9 Al

8/30/2016: Massive re-work is being done on the InfoBox Templates. Read that page to keep up with the plan for that, and adding better keyword tags (categories) to all the pages. --OS-9 Al (talk) 15:28, 31 August 2016 (CDT)


From CoCopedia - The Tandy/Radio Shack Color Computer Wiki
Jump to: navigation, search


CoCoEPROMpak 1.0 Copyright 2013 by Mark J. Blair Distributed under GPLv3

CoCoEPROMpak is a PCB design for an EPROM-based ROM cartridge for the Tandy/TRS-80 Color Computer. It can accept on 2732, 2764, 27128, 27256 or 27512 EPROM. Board thickness must be 0.062". Gold plating is preferable to avoid contact oxidation. Board is designed to the OSHpark design rules for a 2-layer PCB.

When using 27256 or larger EPROMs, the EPROM is divided into 2-4 16k banks which can be selected with jumper settings. Jumper settings are also important for 27256 and smaller EPROMs in order to apply the correct power and control signals to the EPROM.


   * Install 2732 at U1
   * JP2, JP3 not used


   * Install 2764 at U2
   * Set JP2 to 1
   * Set JP3 to 1


   * Install 27128 at U2
   * Set JP2 to 1
   * Set JP3 to 1


   * Install 27256 at U2
   * Select 16k bank with JP2
   * Set JP3 to 1


   * Install 27512 at U2
   * Select 16k banks with JP2 and JP3

CoCoEPROMpak is a free hardware design: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

CoCoEPROMpak is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with CoCoEPROMpak. If not, see <>.