2025 One-Hertz Challenge: ZX Spectrum Is Now A Z80 Frequency Counter

July 18, 2025 by Lewin Day 1 Comment

The ZX Spectrum is perhaps most fondly remembered as a home computer and a games machine. [Tito] has grabbed the faithful black plastic box and turned it into a frequency counter as an innovative entry to our 2025 One Hertz Challenge.

The code was prepared in assembly using ZASM—a Z80 online assembler. It works in quite a simple manner. The code runs for one second at a time, counting rising edges on the EAR port of the ZX Spectrum. Those edges are added up to determine the frequency in question, and the job is done. [Tito] has tested the code and found it’s capable of reading frequencies up to 20 KHz. Since it runs on a one second period, it’s thus eligible for entry by meeting the requirements of the One Hertz Challenge. Code is available on Github for the curious.

The ZX Spectrum has a clock speed of 3.5 MHz, meaning it’s not exactly the tool of choice if you’re reading faster signals. We’ve seen similar done before. In any case, this project was a great way to exercise assembly coding skills and to bust out some classic Speccy hardware—and that’s always a good time. If you’ve got your own retrocomputer hacks brewing up in the lab, don’t hesitate to let us know!

MR Browser Is The Package Manager Classic Macs Never Had

July 18, 2025 by Tyler August 2 Comments

Homebrew bills itself as the package manager MacOS never had (conveniently ignoring MacPorts) but they leave the PPC crowd criminally under-served, to say nothing of the 68k gang. Enter [that-ben] with MR Browser, a simple utility to fetch software from Macintosh Repository for computers too old to hit up the website.

If you’re not familiar with Macintosh Repository, it is what it says on the tin: a repository of vintage Macintosh software, like Macintosh Garden but apparently less accessible to vintage machines.

There are two versions available, depending on the age of your machine. For machines running System 6, the appropriately-named MR Browser sys6 will run on any 68000 Mac in only 157 KB of and MacTCP networking. (So the 128K obviously isn’t going to cut it, but a Plus from ’86 would be fine.)

The other version, called MR Browser 68K, ironically won’t run on the 68000. It needs a newer processor (68020 or newer, up-to and including PPC) and TCP/IP networking. Anything starting from the Macintosh II or newer should be game; it’s looking for System 7.x upto the final release of Mac OS 9, 9.2.2. You’ll want to give it at least 3 MB of RAM, but can squeak by on 1.6 MB if you aren’t using pictures in the chat.

Chat? Yes, perhaps uniquely for a software store, there’s a chat function. That’s not so weird when you consider that this program is meant to be a stand-alone interface for the Macintosh Repository website, which does, indeed, have a chat feature. It beats an uncaring algorithm for software recommendations, that’s for sure. Check it out in action in the demo video below.

It’s nice to see people still making utilities to keep the old machines going, even if coding on them isn’t always the easiest. If you want to go online on with vintage hardware (Macintosh or otherwise) anywhere else, you’re virtually locked-out unless you use something like FrogFind.

Thanks to [PlanetFox] for the tip. Submit your own, and you may win fabulous prizes. Not from us, of course, but anything’s possible!

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Vintage Hardware Find Includes Time Capsule Of Data

July 16, 2025 by Bryan Cockfield 4 Comments

Before social media brought the Internet to the masses, and before even Napster, ICQ, and AIM gave those with a phone line a reason to connect online at all, those who went online often went to a BBS messageboard. By modern standards these text-only environments would have been extremely limited, with only weather updates, stock information, limited news, some email and messaging, and perhaps some classifieds or other miscellaneous information. This was an important time for the early Internet though, and [Nicola] recently discovered a time capsule of sorts from this era.

He first got a tip about a piece of vintage hardware, a DEC VAXstation II which was missing from his collection. But after painstakingly preserving the data on the hard drive he found it had been hosting one of these BBS servers and had plenty of gems from the era to show off. Not only does this build restore the DEC hardware but [Nicola] was able to virtualize the server using the data he recovered on a SIMH emulator, granting insights into how the Internet of this era was used.

[Nicola] also brought the BBS messaging system back online, although he notes that running it on the original hardware wouldn’t be feasible so for now it runs in the cloud. It’s a fascinating look into the Internet of the past, far beyond when many of us first went online as well. For a deep dive on how these systems worked, as well as an introduction to some of the Internet culture of the day, we saw this guide to the BBS a little while ago.

A Chip8 Emulator For 68000-based Macs

July 15, 2025 by Tyler August 22 Comments

Among this crowd, it’s safe to say that the original 68000 Macintosh computers need no introduction, but it’s possible some of you aren’t familiar with Chip8. It was an interpreted virtual machine originally created for the COSMAC VIP microcomputer by [Joe Weisbecker] way back in 1977. It enabled coding simple games on the COSMAC VIP without getting into machine code on the VIP’s CDP1802 processor. For the obvious reason of “Why not?” [KenDesigns] decided to put the two together with Chip4Mac68000, a Chip8 emulator for the original Macintosh.

Chip4Mac68000 is not actually a Macintosh program; it doesn’t run in the System Software. Instead, it is a bootdisk that runs bare-metal on the 68000 processor, bypassing Apple’s ROM completely. Doing that is probably more impressive than emulating Chip8 — anyone who wants to get into writing emulators starts with Chip8. That’s not to knock on anyone who goes to the effort of writing an emulator, it’s just that given its origins in a 1970s micro, it’s understandably a very simple system. Not many people do bare-metal coding on this sort of hardware anymore; it’s not like there’s an SDK you can go grab.

Or there wasn’t, anyway, because in order to get this emulator to work, [KenDesigns] wrote a bare-metal SDK for 68000-based Macs. Note that when he says 68000, he does mean 68000 — anything newer than a Macintosh Classic is out. It’s 68000, not 680xx. It was not a trivial endeavour. In the demo video embedded below, you can see his 512k Macintosh in pieces because he’s been poking at it with a logic analyzer to verify the hardware does what he thinks it’s being told.

If you want to try it out, apparently you don’t need real hardware: [KenDesigns] says MAME is accurate enough to make it all work, but miniVmac is not. No word if it would work on the RP2040-based PicoMac; if you try it, let us know how it works out.

This isn’t the first time we’ve seen people writing new software for old Macs of late. If you’re working new magic on very old machines, drop us a line. We’d love to hear about it.

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An Emulated Stroll Down Macintosh Memory Lane

July 10, 2025 by Tyler August 6 Comments

If you’re into Macs, you’ll always remember your first. Maybe it was the revolutionary classic of 1984 fame, perhaps it was the adorable G3 iMac in 1998, or even a shiny OS X machine in the 21st century. Whichever it is, you’ll find it emulated in [Marcin Wichary]’s essay “Frame of preference: A history of Mac settings, 1984–2004” — an exploration of the control panel and its history.

Image of PowerBook showing the MacOS 8.0 desktop. — That’s not a photograph, it’s an emulator. (At least on the page. Here, it’s a screenshot.)

[Marcin] is a UI designer as well as an engineer and tech historian, and his UI chops come out in full force, commenting and critiquing Curputino’s coercions. The writing is excellent, as you’d expect from the man who wrote the book on keyboards, and it provides a fascinating look at the world of retrocomputing through the eyes of a designer. That design-focused outlook is very apropos for Apple in particular. (And NeXT, of course, because you can’t tell the story of Apple without it.)

There are ten emulators on the page, provided by [Mihai Parparita] of Infinite Mac. It’s like a virtual museum with a particularly knowledgeable tour guide — and it’s a blast, getting to feel hands-on, the design changes being discussed. There’s a certain amount of gamification, with each system having suggested tasks and a completion score when you finish reading. There are even Easter eggs.

This is everything we wish the modern web was like: the passionate deep-dives of personal sites on the Old Web, but enhanced and enabled by modern technology. If you’re missing those vintage Mac days and don’t want to explore them in browser, you can 3D print your own full-size replica, or a doll-sized picoMac.

Whack-A-Disk

July 1, 2025 by Bryan Cockfield 11 Comments

By now most floppy disks have been relegated to the dustbin of history, with a few exceptions for obscure industrial applications using legacy hardware and, of course, much of the world’s nuclear weapons arsenals. In fact, they’re so rare to see in the world anymore that many below a certain age don’t recognize the “save” symbol commonly used in application user interfaces. Without a use case, and with plenty of old floppies still laying around, [Rob] took a pile of them and built this Whack-a-Mole-style game.

The game has a number of floppy-disk-specific features compared to the arcade classic, though. First, there’s no mallet, so the player must push the floppy disks into the drive manually. Second, [Rob] went to somewhat exceptional lengths to customize the drives to that sometimes the disks jump out of the drive, forcing the player to grab them and put them back in to score points in the game. He did this without needing to install high-powered solenoids in the drives too. As for the game software itself, it all runs on an Amiga 600 and even includes a custom-made soundtrack for the 30-second game.

Getting the drives just right did take a number of prototypes, but after a few versions [Rob] has a working game that looks fun to play and is a clever use of aging hardware, not to mention the fact that it runs on a retro computer as well. Of course, for the true retro feel, you’ll want to make sure you find a CRT for the display somewhere, even though they’re getting harder to find now than old floppy disk drives.

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Behind RadioShack’s Cheapest Computer

June 30, 2025 by Bryan Cockfield 30 Comments

In the 1980s, there was a truly staggering amount of choice for a consumer looking to purchase a home computer. On the high end, something like an Apple Lisa, a business-class IBM PC, or a workstation from Sun Microsystems could easily range from $6,000 to $20,000 (not adjusted for inflation). For the time, these mind-blowing prices might have been worth the cost, but for those not willing to mortgage their homes for their computing needs, there were also some entry-level options. One of these was the Sinclair ZX-80, which was priced at an astounding $100, which caused RadioShack to have a bit of a panic and release this version of the TRS-80 computer to compete with it.

As [David] explains in his deep dive into this somewhat obscure machine, the TRS-80 MC-10 was a commercial failure, although not for want of features. It had a color display, a chicklet keyboard, and 4K of RAM, which were all things that the ZX-80 lacked.

Unfortunately, it also had a number of drawbacks compared to some of its other contemporaries that made consumers turn away. Other offerings by Commodore, Atari, Texas Instruments, and even RadioShack themselves were only marginally more expensive and had many more features, including larger memory and better storage and peripheral options, so most people chose these options instead.

The TRS-80 MC-10 is largely a relic of the saturated 80s home computer market. It’s drop in price to below $50, and the price competition between other PC manufacturers at the time was part of the reason for the video game crash of the 1980s, and even led to Steve Jobs getting fired from Apple. There’s not a huge retro scene for these machines either, although there is at least one game developer you can see in the video below from [Spriteworx]. If you want to experiment with some of the standard TRS-80 software, there are emulators that have everything you need.