Just for hobbyists. It's very much over-engineered as a simple Z80 cpu drop-in replacement.
That's not to say I couldn't imagine that someone, somewhere, wakes up to an alert one day that some control board has failed, and it's _just_ the CPU, and the spare parts bin for out-of-production components got water in it and is ruined, and the company is losing millions per hour the system is down. I just don't think that'll be a common story. With full faith in humanity I like to imagine instead that the people responsible for such systems have planned for full control board replacements to be available for use comfortably before unavailability of the Z80 risks a significant outage due to component failure.
A LOT of them. Zilog only announced its discontinuation in 2024.
But that also means that there are A LOT of them out there, and they are cheap and generally extremely reliable parts. So if you rely on a device with a Z80 in it and you're worried about the CPU failing you can have hundreds of these things on the shelf for ~no money.
So I would say it's of limited utility for industrial applications for now simply because scarcity is not an issue for the real thing. This might change in the future so it's good that projects like this exist.
It's sad Z80 production was discontinued. There are some niche IC manufacturers that specialize in legacy parts (eg. Rochester Electronics comes to mind). It would have been nice if Zilog had passed on manufacture of the good 'ol Z80 to a manufacturer like this. Even if it's just small production batches every couple of months/years or so.
There'll be plenty of hobbyists and/or legacy industrial / niche applications for a looong time to come.
The TI-84+ graphing calculator is still popular and a current model and it is Z80 based. (Though I doubt you'll find a DIP40 socket in one for a swap.)
The TI-84+ uses a TI REF 84PLUSB (or variant) ASIC that has a Z80-compatible core in it, not a Zilog Z80, and, as you say, definitely not a DIP40 part.
Thank you! I had a job coding Z80 assembly "back in the day" and grew to love its instruction set so I'm not surprised there is legacy and value to keep stuffing wee Z80ish cores into modern devices.
That's not to say I couldn't imagine that someone, somewhere, wakes up to an alert one day that some control board has failed, and it's _just_ the CPU, and the spare parts bin for out-of-production components got water in it and is ruined, and the company is losing millions per hour the system is down. I just don't think that'll be a common story. With full faith in humanity I like to imagine instead that the people responsible for such systems have planned for full control board replacements to be available for use comfortably before unavailability of the Z80 risks a significant outage due to component failure.