Tom Jennings Opens Orders for Friendly fZ80 CP/M, MP/M Microcomputer "Final Stage Prototypes"
Successful sales of the emulated Zilog Z80-based MP/M machines may lead to the design of an MP/M 'laptop,' its creator says.
Vintage computing enthusiast Tom Jennings has opened orders for a limited run of "final stage prototype" Friendly fZ80 microcomputers — low-cost microcontroller-driven devices designed to introduce a new generation of programmers to the Digital MP/M multi-user operating system.
"Friendly fZ80 is a new, modern desktop computing machine that runs [Digital] CP/M 2.2 and MP/M II 2.1, Digital Research's multi-tasking, multi-user operating system for the 8-bit [Intel] 8080 and [Zilog] Z80 microprocessor," Jennings explains of the device. "It uses a modern (but VGA) display, and modern keyboard and storage. These are semi-hand-made in painted aluminum chassis with nice attention to detail. These are rugged and reliable, approximately 8×4×2"."
Gary Kildall's Control Program/Monitor, later Control Program for Microcomputers (CP/M), is a highly influential operating system for minicomputers and microcomputers — and the inspiration for Microsoft's MS-DOS, a distribution deal for which with IBM would propel the company to its current status as world leader in operating systems. Recently confirmed by current license-holder Bryan Sparks as being available to all to "use, distribute, modify, enhance, and otherwise make available in a nonexclusive manner," the fact that its last official release came in 1983 hasn't stopped fans from continuing to use the software — and the Friendly fZ80 is designed to offer a low-cost platform on which to experiment.
The Friendly fZ80 is designed around modern hardware: rather than the now-discontinued Zilog Z80 or Intel's old 8080, the core processor and its peripherals are emulated on a 32-bit PJRC Teensy 4.1 — a device that, at 600MHz, runs a couple of orders of magnitude faster than the original CPUs. "CPU speed is hard to characterize," Jennings admits, "but the individual peripheral devices (disks, display, keyboard, etc.) consume little resource on the Z80 side, operate in parallel and are orders of magnitude faster than anything from the '70s. User experience is that of a fast machine with transparently ideal characteristics. A crude check indicated 100MHz [equivalent CPU speed]. Good enough."
Jennings has been working on the project a while, but is now ready to open it up to others — and is accepting orders for the first 10 "final stage prototype" machines to be built. "If they sell in a reasonable interval I'll make more," he says. "Capitalism being what it is, I could assemble 50 or 100 of them cheap enough to probably sell them for less. If there's substantial interest the next design [will] be an MP/M 'laptop' … which would be wonderful."
More information is available on the Friendly fZ80 website, along with instructions on how to order one of the limited-edition prototypes at $90; additional details are available in Jennings' Mastodon post.