[Coco] CoCoEPROMpak

Barry Nelson barry.nelson at amobiledevice.com
Thu Sep 8 10:52:57 EDT 2016

The one I am working on with Jim uses an 8 meg EEPROM, which can map either 16k, or on a CoCo 3, 32k at one time. It also emulates the bank switching used in the 64k and 128k game cartridges. It boots up to a customizable menu that allows you to select the rom you wish to run. Jim Brain is designing the hardware and I am writing the software. Here is a video demo showing a prototype in action:


> Mark J. Blair nf6x at nf6x.net 
> Thu Sep 8 05:03:32 EDT 2016
> > On Sep 7, 2016, at 19:29, Barry Nelson <barry.nelson at amobiledevice.com> wrote:
> > 
> > I am working on a Flash ROM project with Jim Brain. Is this similar? What does yours do?
> It might be similar. Mine uses an EEPROM. It will be writable on the CoCo without disassembly, includes a write protect switch, and will fit in an unmodified Super Pak case. The board has the same dimensions as an original Program Pak board or my old CoCoEPROMpak board.
> It can be assembled as an 8k, 16k, 32k, or 128k cart. The 16k version would emulate two 16k carts that can be selected with a switch, while the other sizes each emulate a single cart. The 32k and 128k versions include the necessary bank switching logic for carts of those sizes.  The CART interrupt is switchable, for use with BASIC-like ROMs such as HDB-DOS. Booting of the cart is suppressed in write mode, so that writing a crashing BASIC-like ROM image won't brick the board for users without a Multi-Pak. I think it's unlikely that the 128k version would generate much interest, because the EEPROM on that board will be pretty expensive.

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