Chapter 7: ADBuino

With everything working flawlessly so far it was time to connect the ADBunio. This is where the fun happened. I've already soldered it together beforehand and flashed to firmware on it as good as I could. The documentation of the project was very thin but after a bit of trial-and-error It spit out a binary that seemed to work.

Instead of chopping up a DIN-cable and soldering it to the thing, I decided to solder down a matching connector. After all was prepared, I used a DIN-cable to connect the ADBuino to the Computer, a USB power brick to connect to the secondary micro USB port and a USB-OTG adapter to connect a USB keyboard to the primary micro USB on the pico.

I pressed the power-button, and the display stayed gray with a cursor stuck in the top right. After trying some different combinations: ADBuino without USB-Devices, ADBuino without external power, just the cable to the ADBuino, no ADBuino; it became clear that there's something wrong with how I soldered the project together.

Some

pinout

reading and multimeter measuring later I figured out that I soldered the connector on the ADBuino on backwards. The pinout I was following was for the computer itself, and when using a straight-trough cable the pinout on the device woul've needed to be mirrored.

So I went ahead and fixed the issue. After that the mac would boot up but the ADBunio still wouldn't work. I spent some time looking at the debug-log of the thing and also used my HP 16500C to scope out what's going on. It looked like the signal, that requests data from a connected device, sent from the mac comes trough just fine (blue plot in the photo) but the answer from the ADBuino (greenish-blue) was either all HIGH or all LOW. It probably didn't help that the CRT on my scope is slowly dying. (That's a future blog post right there)

I decides to turn the ADBuino story into it's own blog post at that point. To be able to keep on working on this mac I went on ebay and bought a cheap ADB mouse and keyboard.

A photo of the computer next to a monitor showing a gray screen.

A pinout-diagram for the mini DIN 4 connector used for ADB.

A photo of the screen on a ThinkPad with a serial terminal filled with text.

A photo of a washed-out CRT displaying the interface of an oscilloscope.

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A week had passed since I messed around with the ADBuino when the new hardware came in. I also had mounted the battery holder where the HDD used to be. I plugged in the new mouse and keyboard, turned on the computer and everything worked right away. That's good news because I was worried that there's something wrong with the computer itself after plugging in a wrongly-wired ADB devices.

While I still had the computer open, I also mouted the sd2ide in the back so the SD card would be accessible from behind when the case is closed up.

A ADB mouse and keyboard sitting infront of a monitor next to the computer

A battery holder with cables coming out from the top taped inside a computer.

MacOS booting up with ADB HIDs in front of the monitor.

The IDE SD adapter in a black 3D printed bracket sitting on the back of a PC.

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