A nice kit computer designed by Michael Bauer
with a hex keypad, TV output, and very little RAM, and running the CHIP-8 virtual machine for portable software:
(“The 1KB EPROM contained a simple interpretive programming language known as “CHIP-8”, devised by Joe Weisbecker of RCA Labs. I developed a CHIP-8 interpreter to run on the Motorola 6800 processor. CHIP-8 originally ran on the RCA_COSMAC VIP board.”)
You’ll find the original magazine articles from Electronics Australia and design notes as well as the history of the idea. (“When I got bored with text I/O (and my Teletype got relegated to a MITS Altair 8800 project), I designed and built a video graphics controller board for the D1 kit…”)
In hindsight, I regret down-grading the video format to 64 x 32 pixels. This was done not only to minimize price and board size, but also for CHIP-8 program compatibility. But with RAM prices dropping fast, I should have made it 128 x 64 pixels (1KB of RAM), at least. The PCB would have been bigger, but still not as big as the Cosmac VIP. Also, the VIP game programs could have been modified to run on a larger screen format, but I was under pressure from E/A to finish the articles for publication. Annoyingly, by the time E/A was ready to publish the first instalment, higher density RAM and (single 5V) EPROM chips were readily available. But a further delay due to a design revision would have been unacceptable.
There’s also a modern-day rebuild by David Fry:
(photos from Michael’s site)