CoCoDragon-MultiPakInterface-CC-Multi-Pak_Version_1.2 - This is a clone of the Tandy Radio Shack TRS-80 Color Computer Multi-Pak Interface #26-3024 (which should also be compatible with the #26-3124). This was designed by my nephew "Little John" and his father "Big John" (J.R. as he is known to me). I have made very minor modifications to it. "Little John" designed this thing to work with ATX Power Supplies, which makes sense I guess - that is the most common power supply in the whole of the known universe. Please note that I have not yet tested this but I am ordering boards and will post an update after initial testing has been completed.
There is an OSHPark Page Here: https://oshpark.com/shared_projects/zolH6Sdh
There is a GitHub Page Here: https://github.com/TheLittleEngineers/CoCoDragon-MultiPakInterface-CC-Multi-Pak_Version_1.2
Please note: This is derived from an original design by "Little" John Eric and/or his father "Big" John Robert (J.R.) by "Uncle" Robert Allen. It should be thoroughly scrutinized and verified prior to actual use of any kind. DISCLAIMER: The following article is provided for informational purposes only. Any attempt to modify your computer without the proper skills to do so may void your computer. Any attempt to modify your computer without unplugging it first may void you. This Information is provided "as-is" with no guarantee of fitness for any purpose, either explicit or implied. We disclaim any and all responsibility for losses incurred through the use of this information. By using this information, you are deemed to have accepted these conditions of use, and you agree NOT to sue us. CLARIFICATION: The above disclaimer states as plainly as possible that if you decide to make use of any of the information contained within this document that you do so at your own risk. Designing hardware for the CoCo (ColorComputer) and other vintage hardware is a hobby of ours and is not motivated by any desire of profits. As this is a not for profit venture, obviously we can't afford not to disclaim the use of this information.
As of today, April 11, 2024, this board has been produced and tested by one amazing fellow, here: https://www.smbaker.com/tandy-color-computer-resources Thank You Dr. Scott M. Baker for testing this board for me. I have actually, over the years, designed some twenty or 30 different versions of the Multi-Pak interface from 4,5,6,8 to 16 slot versions. Some are designed to fit in ATX cases, some are designed to be standalone. Some are the size of the FD-500 disk controller, some are smaller some are larger. Some have vertical slots, some have horizontal slots and some have a combination of horizontal and vertical slots. Some have extended ISA buss slots allowing IBM PC cards to actually be plugged in and used. One version was designed to replace the motherboard in the TI-99/4A Peripheral Expansion Box. As I said, I've designed quite a few multi-paks. ALL of these will eventually find their way onto github, although I am currently recovering from a series of heart surgeries, so it may be awhile.
I am also uploading some alternative PAL chips that have some added functionality. They are commented to show what they do and they precede the design of this Multu-Pak but should work with it. The pin assignments may need to be changed but I'll have to look at them when I have the time. It would be an easy fix if needed.