+mytek Posted September 24, 2022 Share Posted September 24, 2022 I think it's time to give this project its own thread. So what is it? I'm trying to create a NEW Colecovision Motherboard that is only 4.5 x 4.5 inches square (11.43 CM). Why you may ask? Because that will match the form factor of a Mini Atari 8-Bit Computer that I previously created which was called the 576NUC+. Simply put, they will look very cute stacked on top of each other Well it'll also be extremely portable, allowing one to toss it into a small bag with a couple of controllers and perhaps an AtariMax Ultimate SD Cart. It Will Have a Case Very Similar to This (only styled to look a bit more like a CV) Case design by @Mr Robot Here's an initial look at the board layout to be used in this new project (EDIT: The image below was merely a test to see if all the chips would fit, it's been superseded by a new layout as of September 26th 2022). MAIN BOARD (4.5" x 4.5") Super Game Module (Plug-In) Yes it has Super Game Module compatibility, as well as a built-in Pause switch with a flashing LED on the front panel to indicate it's being paused. The SGM aspect in this project can not be plugged into an existing Colecovision or ADAM without completely recreating a NEW board to make that possible. The hardware imitating this feature is only designed to work within the CV-NUC+, and nothing else. Point of fact is the circuit as written will not even work on the standard expansion port -- its been designed for internal usage ONLY. It doesn't even utilize a programmable logic device, but instead uses discrete 74xx series chips in a unique configuration mostly of my own making (and a portion of it by @chart45), while benefitting from public knowledge presented on these forums and the ADAM Technical Reference Manual. I'd also like to thank @chart45 for sharing his example circuit and his willingness to answer my questions, @opcode for his written description of the theory of operation, as well as @fieroluke for his added discussion of his own implementation. Oh almost forgot... @leaded solder 's blog about his DIY Colecovision was the thing that initially inspired me to pursue this project. And thankfully there are some great schematics by @ChildOfCv for the Colecovision Console which I have been making good use of. I tried as much as possible to stick with THT components, but when it came to the plug-in SGM, there really was only so much room to work with and still have it fit the form factor I'm after. Although it looks like THT is feasible for most everything in the MAIN board, with one exception (FMS6400 Video Driver) . I haven't yet settled on what switches will get used for ON/OFF and Pause. EDIT: When I get the IC Chips all arranged in the best possible way on the MAIN board, then I'll layer in the capacitors and resistors. And just like what I showed on the Super Game Module, there will be a decoupling capacitor assigned to each IC of the MAIN board as well. A problem I still need to solve is to increase the density of the Super Game Module connection -- still need 10 more connections which I think I have a plan to accomodate. 11 1 Quote Link to comment Share on other sites More sharing options...
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