DMG Main Board Schematic & Circuit (+Arduinoboy) (Page 5 of 5)

what a scary thought

Hay folks,
<tl;dr> I have Eagle schematics of the entire DMG-01 ready for everyone along with a complete CPU board layout </tl;dr>
I recently revisited my work on the original DMG schematics and board layouts, and brought it to a point of completion. I’ve sent the Eagle files over to nitro2k01 to host, so they’ll be available for everyone soon. The completed schematic looks like this:

Thus goes the story of my adventure: After consulting with xiwi over the construction of his original Arduinoboy kit, and his introduction of the Teensyboy to me, I thought there had to be a better way to hook up a DMG to a computer. I found Rolf’s work in Eagle, and came up with a plan. I Craigslist’d 2 DMGs, decimated one and scanned the bare board. I then imported the images into Eagle as rasters, compared against GB Dev, and traced. Once I got the CPU’s board completed, I made my initial post here. The Screen’s board was completed shortly after. Aggravated by the second board (I’m not ‘happy’ with whoever designed it), I dropped the project for a while to work on others. I came back recently, content to not recreate the second board to the same standard as the first, and mapped out the auxiliary boards. I packaged up everything I made to this point into two easily digestible Eagle projects and sent them to nitro. I then started work on the next leg of my quest.

But this is where I am now.

The plan is to do something much like what Rolf was attempting with the Arduinoboy, except with the teensy. Specifically, I want to have a board completely replace everything inside the Gameboy except for the screen’s board, without the need for anything but a tri-wing screwdriver, and run.  I want to have the Teensy’s USB accessible from the Link Port’s location, have a Li-ion battery, better power regulation (if such a combination is possible), and a better onboard headphone amp (with jumpers to bypass for prosound). I want to have the unused Teensy IO to be accessible for mods to the Teensy-duino code. And then I want to make it so it gets into the hands of anyone who wants it.

But that is where my quest will end, and not where I am now.

While I’m here, I thought I’d publish my scans of the front PCB.

Back's full size image | Front's full size image

And while I'm at it, here's all my DMG related plots in a single gallery.

This. Yes. I know. Oh my. Yes.

I haven't found any online chip manufactures that sell the LR35902/8080/Z80/whateveryouwanttocallit CPU. A few claim to be able to fabricate some on demand, but that doesn't look as promising as it sounds. The emulator community has the instruction set well documented if full-crazy is the flavor of choice. But I feel like a 'first things first' approach -- upgrading the power supply and making sure I didn't totally faff up somewhere in the schematic -- seems like a more accessible milestone.
If an objective is to manipulate the DMG-CPU with the Teensy, stuff could get crazy. You could potentially go beyond a simple flash cart, and slave the DMG down to its core. As in, you could transcend LSDJ and have a computer-run tracker do everything except fabricate the actual sound.

But my inner evil genius knows well the taste of hubris.

I *will* throw my voice in here and say that while the Arduino(boy) embedded idea is great, what is even better is the fact that it is possible to have a Teensy 2.0 piggyback on the Arduinoboy's MIDI connections to offer USB MIDI via https://www.pjrc.com/teensy/td_libs_MIDI.html this project AS WELL as DIN MIDI.

This would allow you to have ALL the features of the Arduinoboy carry over through USB in one unit while overcoming the shortfalls of the Teensyboy being a slightly incomplete port of the Arduinoboy code (I think it's due to a lack of a certain kind of MIDI library for the Teensy 2.0 iirc).