The good thing is that, for hobbyists anyway, there are so many used and new-old-stock Z80s floating around that the immediate impact of this won't hit for a while. After that, there are plenty of soft core (fpga) Z80 clones, as well as emulators to run on modern microcontrollers. Zilog also has ISA compatible microcontrollers that can be retrofitted. It's unfortunate that the official Z80 is being retired, but the future of retro-computing is cycle-accurate FPGAs.
I ran into similar issues with Motorola 68k builds. Many of the interesting processors are vintage. So, over time, any builds I open source would become increasingly difficult for folks to build. But, produce a cycle accurate clone core on FPGA, and this ISA can be preserved on a reasonable facsimile of real hardware for generations to come. Thankfully, Amiga enthusiasts have already taken the lead in FPGA preservation.
The Z80 has lasted a few years longer than me in the computer industry. It came onto the market more or less when I left uni and I retired 2 years ago. For several years in the 1980s I worked on Z80 based terminals and CP/M microcomputers. Most of that work was in assembler but I never really liked the Z80 architecture as I'd been spoilt by the orthogonal instruction set of the PDP-11.
I just ordered 3. Old school DIP package. No idea what I'm going to do with them, I'm not really into hobby electronics (although I have messed with breadboards for work).
Make sure you order appropriate support ICs as well, as some of these are EOL too. I would recommend a Z80 DART, since that is actually useful to work with.
As for what to do with them, consider a retro-controller project that you'd typically use an Arduino or similar, or consider porting Microsoft BASIC or CP/M. It depends if you want to be semi-practical by doing something with the former or have a little nostalgia fun by doing something with the latter. These can also interface with an SN76489 to do some old school sound effects and music. With some more advanced interfacing, it would be possible to drive an OPL3 or similar.
> As for what to do with them, consider a retro-controller project
Yeah, problem is i have an arduino and an esp32 plugged into other stuff on my desk right now for work (and a couple Pis with different setups). Because I'm paid to do stuff like that, it's not new and interesting as a hobby.
I'll do look into getting some support chips for the z80s though, thanks.
> These are surprisingly capable CPUs.
I grew up with zx spectrums and some access to cp/m machines :)
I do firmware work as well. There is something nice about building a 65C02 based cellphone, or a fermentation system controller using a 68010 and a CPLD based MPU. A Z80 fits nicely into this.
It's not practical, but it can be an interesting application of art.
You are not alone! I ordered 5 cpus from RS yesterday.
;-)
For what ? I do not know exactly. Rebuilding my first TRS-80 perhaps when I will be retired ? I spent so many years programming on this machine. As I didn't have enough money to buy floppy disk drives, I did everything on tape, with an oscilloscope in the way, to properly adjust the treble and bass to have a good square signal! During eight years !
Yes, it's definitely nostalgia.
Nostalgia for a time when we tried to push technology to the limit to solve small problems, without having to manage dependencies, writing unit tests, doing upgrades ... Time when each computer has its own personality ...
Looking into this a little bit more: it seems that there are actually some Z80 (actual Z80, not Z180, etc.) chips that will remain active. For example, the Z8401510FEG chip is not listed on the end of life notification, and is still listed as "active" at Digikey.
Now the thing is, this chip is a different package than what most people probably expect when they think "Z80" chips. It's QFP, not DIP. So not a "drop in replacement" for many situations. But you can probably use a QFP to DIP adapter or breakout board and use these in many places you'd want a traditional Z80. And if you're designing your own ad-hoc retrocomputer around a Z80, this should work fine, albeit with the constraint that you have to work with QFP chips.
Welp, never mind. Since I posted this, the status on this chip at Digikey has also toggled over to "last time buy" even though this one wasn't on the original announcement that went out. Guess it's time to stock up on whatever stock is in the pipeline, and/or plan to adopt the Z180 or eZ80.
Damn. I know this isn't the end of the world for Z80 retro-computing enthusiasts, but this still does not make me happy. I have a small cache of new Z80 chips already in my parts bin, but now I feel like I need to order a whole pile more just so I'll have extras around.
Or maybe it's just time to pick up a Z180 and start learning to work with that. sigh
They have other chips that can run Z80 code (eZ80, Z180), but none that are drop-in compatible as far as I know. If you're looking at putting one of these in place of a Z80 you'd probably need to either redesign the surrounding computer or essentially treat it as a giant "peripheral" on a new firmware/kernel retooled for the new processor (like some "accelerator" products have done historically).
A bit surprising to be honest. I'd think there will be a continuing market for Z80s. Maybe some niche applications (?), and "there's a new retro-builder hobbyist born every day". FPGAs, emulators etc are nice but not everyone's cup of tea.
It can't be that hard to just do a small production run every once in a while, given that Zilog fabricated these for 40+ years? And there's a few companies / individuals that specialize in these low demand, veerrry long tail markets.
Sadly Zilog never did a 3.3V (or >20 MHz) version of the good old Z80. Only newer (but not quite 100% compatible) parts like Z180 & eZ80. And if I could dream: I'd like to see such an updated Z80 in some beautiful package. Say, a small PGA with quartz window to see the chip (frit-seal), in a couple of different colored ceramics, gold-plated pins, the works. Then present that @ Z80's 50th anniversary? /dream
Yeah, i'm restoring a Compucorp 625 at the moment, which was made in 1978 and is Z80 based - not a bad run!
I guess we should really applaud the Intel 8080 for starting this, but probably the brilliance of the Z80 was simplifying the external requirements. The 8080 required +5v, -5v and +12v, and I think some external clocking and DRAM refresh, whilst the Z80 was just +5v, and integrated clocking and refresh to get the component count down.
I would say 6502 < Z80 (cheaper in a good way leaving more for graphics+sound support chips).
The first time I used dBase II on a Xerox C/PM machine was when I realized what a business computer could be like. It seemed standardized more than the PETs or TRS80s.
> The 6502 needs access to memory only half the time, during the what is usually called the ϕ2 phase of the clock. The other half of the time, so long as you tri-state the CPU address pins,² the bus and memory are available to other systems.
> The Z80 does not have such a well-defined, synchronous system of accessing RAM. Many cycles don't need RAM access, but many do, and which particular ones do and do not depend on the instruction mix.
> There is no "do nothing" solution to this constraint, and Z80-based systems that wanted consistent video output would have to solve this one way (hardware) or the other (software).
I ran into similar issues with Motorola 68k builds. Many of the interesting processors are vintage. So, over time, any builds I open source would become increasingly difficult for folks to build. But, produce a cycle accurate clone core on FPGA, and this ISA can be preserved on a reasonable facsimile of real hardware for generations to come. Thankfully, Amiga enthusiasts have already taken the lead in FPGA preservation.