Olimex Founder Tsvetan Usunov Begins Work on an RP2040-Supported MOS 6502 Retro Computer
Following the success of the Agon Light fork, Olimex is preparing to design and release a low-cost reduced-chip count MOS 6502 board.
Olimex founder Tsvetan Usunov is working on a new retro-themed single-board computer based on the MOS Technology 6502, or its modern compatibles — and packing a Raspberry Pi RP2040 as a support chip, emulating much of the remaining hardware that would go into such a device.
"I will admit, I have a sentiment for retro computers," Usunov explains. "This is probably because my career in IT started many years ago with the Bulgarian Apple II clone called IMKO2, later renamed to Pravetz 82. Two weeks ago, I started thinking, as an engineering challenge, is it possible to build a modern peripheral 6502 computer that is with the lowest possible cost."
That proposed computer is the Neo6502, envisioned as an open-source blend of modern and vintage devices. Its heart is the iconic MOS 6502, though likely as a modern equivalent from The Western Design Center (WDC), while costs and complexity are to be kept down by using a Raspberry Pi RP2040 to emulate much of the remaining hardware which would traditionally have been on multiple independent chips.
The RP2040, Usunov explains, will carve out at least 64kB of RAM for the system, with bank switching if more is required, serve as the system's clock, offer a DVI-based digital video output via an HDMI port, use its USB port to connect a modern keyboard, emulate a SID-style sound chip, and provide non-volatile storage.
The Neo6502 is far from Usunov's first brush with retro computing. Late last year he forked Bernardo Kastrup's Agon Light design, a stand-alone eight-bit BASIC microcomputer, converting the project from EasyEDA to KiCad and tweaking the design for some modern conveniences — as well as compatibility with Olimex's UEXT connector for solder-free external hardware connectivity.
"I have already obtained all the parts together and will have a proof of concept on a breadboard [soon]," Usunov explains. "Then, we will design PCB and some prototypes in a few weeks. If you want to participate in software/firmware development for both RP2040 and 6502, you are welcome to join us! We will have some free early prototypes to send to developers. Send us email to info at olimex dot com."
More information is available on the Olimex blog.
Main article image courtesy of Christian Bassow, CC BY-SA 4.0.
