A Curiously Strong Z80 In Your Pocket

Like many hackers, [Tom Szolyga] has soft spot for the venerable Z80. The number of instructions and registers made it relatively easy to program in ASM, and he still has fond memories of the refreshingly straightforward CP/M operating system he used to run on them back in the day. In fact, he loves Z80 computers so much he decided to build one that he could carry around in his pocket.

The result is the Minty Z80, so-called because it lives inside a tin formerly inhabited by every hacker’s favorite curiously strong mint. But the goal of this build wasn’t just to make it small, but also make it convenient to work with. [Tom] is using a ATmega32A to help interface the Z84C0008 microprocessor with the modern world, which allows for niceties such as support for a micro SD card. There’s no onboard USB-to-serial capability, but with an external adapter connected to the Minty’s header, it’s easy to use log into this microcosm of classic computing with a terminal emulator running on a computer or mobile device.

[Tom] has provided the schematics and Bill of Materials for the Minty Z80 on the project’s Hackaday.io page, but as of the latest update, he’s holding off on releasing the board files until he’s sure that all the bugs have been worked out. There’s no word yet if he found any show stoppers in the first iteration of the board design, but he’s posted a picture of the fully assembled miniature retrocomputer in all its glory which seems like a good sign.

The design of the Minty Z80 is similar to that of the Z80-MBC2 by [Just4Fun], but on an even smaller scale. It’s encouraging to see several projects leveraging modern design and components to prevent classic computing from becoming little more than a distant memory.

42 thoughts on “A Curiously Strong Z80 In Your Pocket

    1. Or, if one can’t just do it with TTL chips, the way old computers were actually made, one could just recreate them with FPGA/CPLD and limit the whole thing to two chips (one being RAM) and microSD card…

        1. some people have photo albums. to me the z-80 helped launch a career that took a displaced farm kid a long ways! z-80 was the first assembly language i used, and it powered keyboards for many years thereafter. can’t say the same nostalgia for much else. Btw – THIS is hacking! Tom likely didn’t have a REDDIT support team, or a YouTube video to help here. just saying, he did a nice job!

    2. What is the point of making anything? That differs for everyone. Some just follow their muse. Some just want to have fun. Some are trying to learn something. Some want to improve something. The important part is that you do something, and not just complain.

      Speaking of which, did you already start on your emulator? When can we expect to see the first prototype?

      1. This is second Z80 HaD Prize entry from this year. There are at least 40 Z80 retrocomputers or retroconsoles I can think of that emerged in recent years. I don’t see the point of making the same project again and again and again and again. And again. All of therm featuring mix of original chipset and a modern-ish MCU as a glue logic and/or interface…

        1. Monet infamously painted the same subject dozens of times. There’s 250 different variations on Water Lilies alone. And that’s just one guy. Something doesn’t have to be original to be worthwhile.

      2. I have no need for such a thing personally, I just would find a Z80 emulator for a modernish 8-bit a more interesting retrocomputing project than the Nth “retro” board with a modern microcontroller, often more powerful than the original CPU, stuck on it. It’s fine to do this for fun of course, there’s a lot to be learned from reinventing the wheel, it just seems overdone.

          1. hell yeah! thats how we learn, relax, and innovate!

            I’d rather see this than Object oriented “coders” projects! understanding how these “classics” work stretches your brain and makes ALL OF US smarter! without the z-80 most likely we would never have seem the intel 8080 or 8086 processors. definitely not the PC in 1981. these z80 processors were the Rpi of the day!

        1. What’s the point in reading a book for the Nth time? It’s already been read by someone else.
          What’s the point in playing baseball for the Nth time? It’s already been played by someone else.
          What’s the point in eating pizza for the Nth time? It’s already been eaten by someone else.

    3. Yeah I agree these kind of suck, i.e. they are more valuable for the creator in creation than afterwards, or to anyone else.

      But there might be some value in it for those who wish to do something similar in the future.

      I would actually love something like this, like the Digirule2 but easier to program for utility.

      I’m *not* sure what it could do other than be a fancy slide rule/caliper.

      1. “More valuable for the creator” could describe 90% of what is on HaD. People build these because it’s what they want and suits their goals. This particular guy wanted an easy/cheap way to relive the Z80 glory days, and this is how he did it. Who is anyone else to tell him he’s wrong?

    4. Absolutely. That’s why Ben Eater is just building a computer straight up from original components, even the VGA part. The problem is the complexity of modern micros. Too many IPs just tossed onto a die without useable documentation. People are willing to do odd and strange things to get back to the simplicity of the past.

      If FPGA toolchains were more accessible, that would be the optimum solution. People complain about ‘rolling your own’ in the sofware and hardware worlds, but both areas have become so complex that it’s becoming more reasonable to roll your own instead of putting the time in learning some multi-layered conglomerate’s API and finding out it doesn’t do what you need it to do (possibly) months later.

  1. If you use a PC as a terminal, then it is far more powerful peripheral already. So much for purist’s hate of attaching modern parts…
    It isn’t a strong Z80 as the article implies. There were newer variations from the Z18x SoC to the Rabbit 2000/3000/4000 families. I for one would like to see these used instead.

  2. “a tin formerly inhabited by every hacker’s favorite curiously strong mint.”

    I came to say that I don’t get it. Why haven’t Penguin Mints taken over Altoids place as a project box yet? Their tins were physically identical to Altoids tins but the mints are caffeinated and the logo is a penguin. Come on, Penguins, Caffeine! How is this not a cornerstone of geek culture? Just wash them down with some Bawls and you are set!

    I hadn’t seen them in a while though. I moved away from the city with the mall that I used to buy them in. I decided to Google it just to make sure they are still “a thing” before posting. Their website is selling them in boxes, not tins and the only tins I find are on Amazon but out of stock and unknown when they are coming back.

    No more Penguin Mint tins? Do they not make them anymore? Did Altoids sue them maybe?

    No!!!!!! It can’t be!!!!!!

    I want to wake up from this nightmare now please.


  3. I claim having a soft spot for the Z80 correlates much more strongly with being a hacker than having tasted some random candy nobody has ever heard about. (See, I can make false generalizations too!)

  4. Congrats on your design! Not exactly the first Z80 in a mint box (see Lee’s Z80 Membership Card), but it’s great to see other people building stuff! Modern chip to interface the old chip… well, there’s mixed feelings about that, but I say anything that gets the job done and is creative is definitely worth doing! The only disappointment of this Z80 computer is that it’s missing a front panel with LED’s, see how Lee did it and compare.

  5. I’m not asking for much, all I want is an Open Source Z80 based “tin sized” computer that can run Timex-Sinclair programs, or any other Z80 programs easily, with gobs of EEPROM and RAM, with excellent documentation, has modern hardware features such as USB, microSD storage, HDMI/VGA/DisplayPort, Cat5, WiFi, IR, low battery consumption and under $30.

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