Tim Holyoake Brings Back the Sharp MZ-80K, Now Powered by a Raspberry Pi Pico's RP2040

Vintage computing enthusiast Tim Holyoake is looking to make it easier for people to play around with a Sharp MZ-80K microcomputer — by creating an emulation of one that runs on a $4 Raspberry Pi Pico microcontroller, now available in beta.

"After playing with a couple of Sinclair ZX emulators, I had a look for a Sharp MZ series one," Holyoake explains of the project's origins. "There are a number available (there are a couple of very good ones), but they all run on [Microsoft] Windows, Linux, FPGAs, or specialist hardware of some description. Nothing for the [Raspberry Pi] Pico. So… that sounded like a challenge to me."

Released in 1978, the Sharp MZ-80K was a text-centric microcomputer in the Sharp MZ family offering 48kB of RAM, of which 32kB was available to the user, and a Zilog Z80 eight-bit processor. Despite its relatively high price, the device proved popular both in its native Japan and in Europe — though it's not too easy to find in working order these days, thanks to age-related degradation of its integrated tape deck and built-in CRT monitor.

For those who want to find out why the device was so popular, or revisit their misspent youth, Holyoake is working on an emulator that brings the device to a more accessible platform: the $4 Raspberry Pi Pico and its dual-core RP2040 microcontroller. As an indicator of just how far we've come in the decades between the two, the best performance comes when you run the RP2040 below its stock speed — clocking it down at 100MHz, which is still two orders of magnitude faster than the Z80 in the original Sharp MZ-80K.

"I’m still working my way through a lot of MZ-80K software, but as the emulator seems to be holding up well I've let a beta version escape into the wild," Holyoake writes. "I've not uploaded any source code yet – so you’ll have to ignore the systems manual part of the documentation for the time being – but my intent is to let version 1 escape on 31st October. Halloween. Seems appropriate!"

More information is available in Holyoake's Mastodon thread, and on his website; the beta build is available to download as a precompiled U2F file from GitHub, and requires a Raspberry Pi Pico — not the newer RP2350-based Raspberry Pi Pico 2 — and a Pimoroni VGA Base or compatible carrier board.