Single-Board Computer

My 8088-based single-board computer (SBC) was the final project for Microprocessor Systems (ECE 424) in the Fall semester of 2001 at SIUC. As a functional device, it’s little more than a novelty. However, it was the first computer that I successfully designed and built at the chip level.

As the following image shows, the SBC uses an EPROM for storage, has a serial port for communication, banana ports for power and ground, and a blue button that functions as a reset switch.
8088-based single-board computer - Front

The following image shows the back of the SBC.
8088-based single-board computer - Back

This was a rougher project for me than it should have been, due to the politics of SIUC and how they played out in the student body. It was meant to be a group project and I paired up with a straight-A student, thinking that would be the best move. He showed up to our first planning meeting with a schematic he’d procured from the course’s TA, handing it over as his contribution to project planning. I ignored that schematic and built my own design based on the project description. Later, he showed up to another meeting with working demo code, which he probably also got from the TA. I was forced to use that code for testing and demonstration, only due to lack of time to write new demo code. The only thing that made me feel even halfway OK about it was that it’s probably what the rest of the class did and, most likely, I had the only unique SBC design.

Our first attempted test was a failure. I spent approximately 8 hours with a multimeter, checking the entire board for shorts and breaks. After checking the whole board twice and finding no wiring errors, it failed another test. I ended up tearing out all my beautiful wiring and rewiring the whole circuit the night before the scheduled demo. It finally passed its first test just before our scheduled demo slot, by which time I hadn’t slept in 36 hours.

We were asked to demo later than expected and the professor interpreted “I need to turn the logic analyzer back on because it just turned itself off” as “our project doesn’t work”. He walked out of our demo while I was turned around. After hunting him down, explaining the situation a few more times, and begging him profusely to watch our demo, he relented and let us finish. As far as I know, we were given full marks for the demo.

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