Derek Robson's Alius 6502 Is a Do-It-Yourself MOS Technology 6502 Trainer for Education and More
"Working in assembly," Robson promises, "will get you to understand what is really going on in the computer."
Self-described "computer security nerd" and vintage computing enthusiast Derek Robson has released an open source single-board computer designed to mimic vintage trainers of the 1970s and 1980s — and featuring a genuine, rather than emulated, eight-bit MOS Technology 6502 processor at its heart.
"The Alius 6502 is a DIY educational computer kit that anyone can build, no matter your experience level," Robson claims of his design. "Whether you’re new to computers or already tech-savvy, Alius 6502 is designed to help you learn more about how computers work. The Alius 6502 isn’t just about building a computer, it's about understanding it. Through the project you will learn the nuts and bolts of computing in a fun, hands-on way."
The inspiration for the Alius 6502 is plain to see: the microcomputer trainers released in the 1970s and 1980s, just prior to the true home computing market's Cambrian explosion, which were designed as low-cost demonstration platforms for their respective microprocessors. With the MOS 6502 at its heart, the Alius 6502 is most like the Commodore KIM-1 released in 1972 — and uses primarily period-appropriate components, bar a breakout board for modern microSD Card storage.
The hardware is only half the story, though: Robson has also designed a custom operating system stored in ROM and various demo programs to put the computer through its paces — and has then made the choice to release everything, from source code and hardware design files to production files for the PCBs, under an open source license.
The Alius 6502 also has its own 91-page user guide, which is, as you'd expect, also open source. walking the reader through the system's specifications — a 6502 running at 1MHz, a generous 32kB of RAM, 16kB ROM, two 65C22 input/output chips, a six-digit LED display, hex-entry keypad, and the microSD card storage system — and demonstrating how to program the device. "Most modern programming is done in a high level language like Python or PHP," Robson writes, "but working in assembly will get you to understand what is really going on in the computer."
More information on the project is available on Robson's website, with links to the GitHub repositories where the design is made available under the reciprocal GNU General Public License 3.