2026 Retrocomputing Challenge: Explore Space With A Credit Card Reader

October 27, 2026 by Tom Nardi 5 Comments

The humble credit card reader — most of us have used hundreds, perhaps even thousands of them over the years. But even for folks like us, it’s not the sort of device we give a lot of thought to. It’s just a keypad, a display, and a magnetic stripe reader. How interesting could it possibly be?

That may be true in some cases, but at least for the 1990s-era TRANZ 330, there’s a bit more to the story than that. As [CharlesD] explains, these particular readers are essentially complete Z80 computers just waiting to do something more exciting than processing PINs. In the case of this particular unit, the addition of a GPS module and some new code has turned it into an interactive guide to the solar system.

Thanks to the UV erasable ROMs used in the TRANZ 330, loading new code on the device is easy enough. With a bit of educated poking around, [CharlesD] was able to map out what did what. Working from the basics of getting the display and keypad working, he moved onto the serial interface, which in turn let him communicate with a modern GPS module and era-appropriate thermal printer. From there it was just a matter of getting the math implemented to compute the azimuth and elevation of a given planet, and he had an offline map of the solar system for use with his telescope.

This is one of those projects which is awesome enough on its own merits, but it’s particularly exciting to see just how easy it is to repurpose one of these card readers, especially since [CharlesD] was kind enough to share his source code. If you end up picking one of these up and getting something running on it, be sure to let us know.

Littelfuse Announces Retirement Of The EZ80

October 11, 2026 by Maya Posch 36 Comments

Although the demise of the Zilog Z80 processor has long been predicted, it would seem that this moment has finally arrived. The owner of the Zilog name – Littelfuse – recently sent out PCN ZAC26-0074, notifying customers that they will be taking final orders for the eZ80 and all other microcontroller lines that they currently own.

Over at Mouser, eZ80 parts have correspondingly all been marked as “End of Life”. This comes a few years after the original Z80 and its peripherals were discontinued, with the eZ80 still being an alternative until now.

Any potential sellers will have to put in their orders today, with orders still accepted until December 21 2026, with final deliveries taking place throughout 2027 as Littelfuse winds down its MCU manufacturing. This means that for commercial customers are least this is pretty much the end of the road for any circuit that still uses the eZ80 or similar.

Many of us have fondness for the Z80, which also has led to a potential way that the Z80 can live on. This includes both the many open source cores that are compatible with the Z80, as well as real silicon courtesy of the TinyTapeout project.

Thanks to [Techokami] for the tip.

BASICally, Its Retro Machine Language

July 23, 2026 by Al Williams 30 Comments

We enjoyed [Beej’s] trip down memory lane looking at a BASIC game, The Wizard’s Castle, written for the Exidy Sorcerer. It appeared in a 1980 magazine that included the title graphic above. It reminded us how, back in those days, we did things with BASIC that you shouldn’t be able to do and it often looks, today, rather cryptic.

In particular, even if you know modern BASIC, these few lines might give you a pause:

10 REM"_(C2SLFF4
40 POKE 260,218: POKE 261,1: T = USR(0): T = PEEK(-2049)
80 Q = RND(-(2*T+1))

Line 10 is a comment, but a strange one. Certainly that doesn’t matter, right? Actually, it is a key part of the action. On line 40, you can see some pokes to write directly to memory and a peek to read some memory value back. The USR function calls some machine language program. You may realize the whole thing is to get some value T to seed the random number generator in line 80.

This leads to a few obvious questions. First, how does USR know what to call? Second, where is the machine language program? The details varied by system, of course, but in this case, the program knows that location 259 has a jump instruction that USR called. So poking an address into 260 and 261 was telling USR where it should go.

But what’s at that address? Keep in mind that an old computer like the Sorcerer didn’t have megabytes of memory being swapped about by an operating system. That means that things tended to be in known places and that BASIC had to be judicious about storing source code.

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Remembering The Zilog Z80 As It Turns Fifty Years Old

July 19, 2026 by Maya Posch 35 Comments

Perhaps the saddest thing about the Zilog Z80 is that this humble 8-bit microprocessor wasn’t allowed to live until its 50th birthday. This, fortunately, doesn’t prevent people like [David Oberhollenzer] from reminiscing on this influential processor and what it means to them personally.

First released in July of 1976, this humble 8-bit miracle would go on to power not just a range of home computers, but also be found in everything from industrial controllers to arcade systems. Despite this success, the new owner of Zilog — Littelfuse — decided to put an end to this winning streak in 2024 for the stand-alone processor and its peripherals.

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Yesterday’s Technology, Re-engineered Today

July 4, 2026 by Elliot Williams 12 Comments

Watching [sprite_tm]’s build of a handheld 486-based gaming computer, we got to thinking about retro computers and the eternal questions of how much of the computer needs to be actually “old” for it it be retro. Where is the soul of a retro computer? The CPU? The old yellowing plastic case? Maybe it depends on what you’re trying to get out of the hobby.

There is of course a spectrum of people playing around with old computers. For some people, let’s call them “vintage computer enthusiasts”, half of the fun is in keeping the actual old hardware running. This group tends to know what teletype lubricant smells like, and how to tell which capacitors need replacing.

For others, “team retro”, the joy is in using the machine itself, whether that be teaching the old dogs new tricks, or simply loading up nostalgic video games. Team retro is more content with emulations or emulations that are wrapped up neatly in hardware workalikes. They know which registers need POKEing, and whether or not Commander Keen is running at the right framerate.

I think [sprite_tm]’s project falls in with yet another camp, the retro-reengineers. Here, the idea is to step through the engineering lessons of the past by re-designing something from a bygone era. So when [sprite_tm] went with a period 486 CPU backed up by a modern FPGA, perhaps ironically borrowing code from the modern MiSTer project, it makes sense for his goals. Retro-reengineers know the bus architecture and the memory timings, and they are reinventing the wheel as a learning experience. Or in the case of [Voja Antonic]’s imaginary four-bit machine, it’s a teaching experience.

How you work often reflects what you’d like to get out of the project, and at Hackaday, of course, we love all of the above! We’ve identified at least three broad schools of fooling around with old computers. Are we missing any?

Can Claude Write Z80 Assembly Code?

April 19, 2026 by Tyler August 28 Comments

Betteridge’s law applies, but with help and guidance by a human who knows his stuff, [Ready Z80] was able to get a functioning game of Wordle out of the French-named LLM, which is more than we expected. It’s not like the folks at Anthropic spent much time making sure 40-year-old opcodes were well represented in their training data, after all.

For hardware, [Ready Z80] is working with the TEC-1G single-board-computer, which is a retrocomputer inspired by the TEC-1 whose design was published by Australian hobbyist magazine “Talking Electronics” back in the 1980s. Claude actually seemed to know what that was, and that it only had a hex keypad — though when [Ready Z80] was quick to correct it and let the LLM know he’s using a QWERTY keyboard add-on, Claude declared it was confident in its ability to write the code.

As usual for a LLM, Claude was overconfident and tossed out some nonexistent instructions. Though admittedly, it didn’t persist in that after being corrected. It’s notable that [Ready Z80] doesn’t prompt it with “Give me an implementation of Wordle in Z80 assembly for the TEC-1G” but goes through step-by-step, explaining exactly what he wants each section of the code to do. As [Dan Maloney] reported three years ago, it’s a bit like working with a summer intern.

In the end, they get a working game, but that was never in question. [Ready Z80] reveals over the course of the video he has the chops to have written it himself. Did using Claude make that go faster? Based on studies we’ve seen, it probably felt like it, even if it may have actually slowed him down.

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Who Had “New OS For The Z80” On Their 2026 Bingo Card?

April 12, 2026 by Tyler August 7 Comments

Some might say the venerable Z80 doesn’t need another operating system, but [Scott Baker] obviously disagrees. He has come up with a brand new, from scratch OS called NostOS for the Z80-based RC2014 homebrew retrocomputer. [Scott] describes it as CP/M-like, but it’s not CP/M– in fact, it’s totally incompatible with CP/M–and has a few tricks of its own up its sleeve.

As you might expect of an operating system for this vintage of hardware, it is “rommable” — that is, designed to run from read-only-memory, and fit inside 64kB. It of course supports banking memory to go higher than that 16 bit limit, and natively supports common serial devices, along with the good old WD37C65 floppy controller to get some spinning rust into the game. Of course if you don’t have floppies you can plug in a compact flash card– try that with CP/M– or, interestingly Intel Bubble Memory. [Scott] has a soft-spot for bubble memory, which at one point seemed poised to replace both hard drives and RAM at the same time. We also appreciate that he included drivers for vacuum fluorescent displays, another forgotten but very cool technology. Back in the day, this operating system would have enabled a very cool little computer, especially when you take his implementation of text-to-speech with the SP0256A-AL2 chip. Fancy a game of talking Zork? Yes, he ported Zork, and yes, it talks.

The whole thing is, of course, open-source, and available on [Scott]’s GitHub. Unlike too many open-source projects, the documentation is top-notch, to the point that we could picture getting it in a three-ring binder with a 5 1/4 floppy on the inside cover. If you like video, we’ve embedded [Scott]’s walkthrough but his blog and the docs on GitHub have everything there and more if you’re not into rapidly-flickering-pixels as an information exchange medium.

[Scott] isn’t wedded to Zilog, for the record; this OS should run on an Intel 8080, perhaps like the one in the Prompt 80 he restored last year.

Thanks to [Scott Baker] for the tip!

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