Anders Nielsen's 65uino Puts an Eight-Bit Chip From the 1970s on an Arduino UNO-Compatible Board
Designed for compatibility with existing Arduino shields, the 65uino looks to turn education on its head by starting at a very low level.
Self-described "obscure IC enthusiast who likes shiny lights" Anders Nielsen has designed a MOS 6502-based educational microcomputer platform which borrows a very familiar layout from Arduino's most popular board family: the 65uino.
"This project aims to give students and hobbyists a strong foundation by focusing on the separate core system components rather than just teaching to use a black box," Nielsen explains of his board design, which mimics the rough layout of an Arduino UNO. "Inspired by my 6502-based 'Single Breadboard Computer' that seemingly does the impossible by squeezing a whole 6502-based computer onto a single breadboard, this project takes the concept one step further by successfully squeezing all the required components into an Arduino-compatible form factor."
Designed for a different approach to electronics and computing education, moving from a high-level-first approach to building a foundation of understanding at a lower level on relatively simple and resource-constrained hardware, the 65uino uses the smaller MOS 6502-compatible 6507 eight-bit processor running at 1MHz to 3MHz, 4kB of ROM, and 128 bytes of RAM as part of the MOS 6532 RAM-IO-Timer (RIOT) chip which makes up the third maker component on the board.
"When I put together projects like this I can't help but feel people look at it like some sort of steampunk alternate timeline but where ICs [Integrated Circuits] stopped shrinking in the '70s instead of the during the industrial revolution," Nielsen says. "Just because IC packages have shrunk quite a bit over the past 50 years there's still quite a lot to learn from the integrated circuits that powered the home computer revolution and beyond.
"Concepts like memory addressing, stack, busses, interrupts, and machine language instructions — at least to me — really are a lot easier to get a firm grip on if you can point at a component and say 'when I address I/O, this chip sets these voltages to indicate to this other chip what we want to do' instead of a single package doing all the work."
A key feature of the design is that it mimics not only the physical dimensions but also the footprint of the Arduino UNO family — meaning that it should be possible to take existing Arduino shields and connect them directly to the 65uino. On the software side, though, you'll have to write your own: "The board uses an Arduino-compatible form factor but is not compatible with the Arduino IDE (yet, anyway)," Nielsen admits.
More information on the work-in-progress project, which is still in the PCB design stage, is available on Nielsen's Hackaday.io page, while the Single Breadboard Computer on which the 65uino is based has been released on GitHub under the Creative Commons Attribution-NoCommercial 4.0 license.