BIOS Detectives Find Ghost Of Previously Unknown PC

November 8, 2025 by Jenny List 22 Comments

Old parts such as EPROMs will often find themselves for sale on sites such as eBay, where they are sometimes snapped up by retrocomputing enthusiasts in search of interesting code. Vintage Computer Federation forum member [GearTechWolf] picked up a clutch of IBM-labelled chips, and as int10h reports, stumbled upon a previously unknown PC-AT BIOS version which even hints at a rare PC model as yet unseen.

The IBM AT and its various versions are extremely well known in the retro PC world, so while this was quickly identified as an IBM BIOS from 1985 and narrowed down to a member of the AT family, it didn’t fit any of the known versions which shipped with the ubiquitous 1980s computer. Could it have been from an industrial or rack mount variant? It’s a possibility, but the conclusion is that it might contain a patched BIOS version of some kind.

Lacking real hardware, it happily boots on an emulator. It’s another piece of the PC historical jigsaw for people interested in computer history, and with luck in time someone will unearth an example of whatever it came from. If you find it, try a modern OS on it!

Talking Robot Uses Typewriter Tech For Mouth

August 8, 2025 by Lewin Day 15 Comments

Many decades ago, IBM engineers developed the typeball. This semi-spherical hunk of metal would become the heart of the Selectric typewriter line. [James Brown] has now leveraged that very concept to create a pivoting mouth mechanism for a robot that appears to talk.

What you’re looking at is a plastic ball with lots of different mouth shapes on it. By pivoting the ball to different angles inside the head of a robot, it’s possible to display different mouth shapes on the face. By swapping mouth shapes rapidly in concert with recorded speech, it’s possible to make the robot appear to be speaking. We don’t get a great look at the mechanism that operates the ball, but Selectric typeball operation is well documented elsewhere if you seek to recreate the idea yourself.

The real benefit of this mechanism is speed. It might not look as fluid as some robots with manually-articulated flexible mouths, but the rapid mouth transitions really help sell the effect because they match the pace of speech. [James] demonstrated the finished product on Mastodon, and it looks great in action.

This isn’t the first time we’ve featured [James Brown]’s work. You may recall he got DOOM running on a tiny LEGO brick a few years back.

Thanks to [J. Peterson] for the tip!

ASCII To Mainframe

April 8, 2025 by Al Williams 11 Comments

IBM mainframes are known for very unusual terminals. But IBM made many different things, including the IBM 3151 ASCII terminal, which uses a cartridge to emulate a VT220 terminal. [Norbert Keher] has one and explains in great detail how to connect it to a mainframe.

It had the 3151 personality cartridge for emulating multiple IBM and DEC terminals. However, the terminal would not start until he unplugged it. The old CRT was burned in with messages from an IBM 3745, which helped him work out some of the configuration.

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Retrotechtacular: Point-of-Sale Through The Years

February 8, 2025 by Dan Maloney 12 Comments

In days gone by, a common retail hack used by some of the less honorable of our peers was the price tag switcheroo. You’d find some item that you wanted from a store but couldn’t afford, search around a bit for another item with a more reasonable price, and carefully swap the little paper price tags. As long as you didn’t get greedy or have the bad luck of getting a cashier who knew the correct prices, you could get away with it — at least up until the storekeeper wised up and switched to anti-tamper price tags.

For better or for worse, those days are over. The retail point-of-sale (POS) experience has changed dramatically since the time when cashiers punched away at giant cash registers and clerks applied labels to the top of every can of lima beans in a box with a spiffy little gun. The growth and development of POS systems is the subject of [TanRu Nomad]’s expansive video history, and even if you remember the days when a cashier kerchunked your credit card through a machine to take an impression of your card in triplicate, you’ll probably learn something.

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Retro Big Iron For You

January 8, 2025 by Al Williams 30 Comments

Many of us used “big iron” back in the day. Computers like the IBM S/360 or 3090 are hard to find, transport, and operate, so you don’t see many retrocomputer enthusiasts with an S/370 in their garages. We’ve known for a while that the Hercules emulators would let you run virtual copies of these old mainframes, but every time we’ve looked at setting any up, it winds up being more work than we wanted to spend. Enter [Ernie] of [ErnieTech’s Little Mainframes]. He’s started a channel to show you how to “build” your own mainframe — emulated, of course.

One problem with the mainframe environment is that there are a bunch of operating system-like things like MVS, VM/CMS, and TSO. There were even custom systems like MUSIC/SP, which he shows in the video below.

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Typo

November 18, 2024 by Kristina Panos 15 Comments

Ceci n’est pas une keyboard, sure. But it’s keyboard-adjacent, and how. [Joshua Bemenderfer]’s wrists are tired of moving off the keyboard in order to mouse, and he decided to create a trackball that can sit just below the Space bar. The idea is to get rid of the regular mouse entirely if this works out.

A split keyboard with a DIY trackball beneath the Space bar. — Image by [Joshua Bemenderfer] via Hackaday.IO

And sure, the Ploopy family of open-source mice would welcome him with open arms, but they don’t come cheap. [Joshua]’s plan here is to make something for under $10. Ideally, less than $5.

Starting with an off-the-shelf trackball, the first BOM came in around $25 if you throw in $5 for the 3D printing of the case. [Joshua] added some cheap ceramic bearings to make it better. Since this was still too high, he turned to the internals of cheap mice.

Trial and error has resulted in a 99-cent special from Ali being the idea candidate. There are even cheaper mice to be had, but this one has an ideal layout for doing a bit of surgery. It also requires remapping since [Joshua] is flipping the sensor upside down and using a POM ball on top of it. Now he just needs to figure out how to add buttons and make them split keyboard-friendly.

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Ruined 1993 ThinkPad Tablet Brought Back From The Brink

November 18, 2024 by Lewin Day 11 Comments

Collecting retrocomputers is fun, especially when you find fully-functional examples that you can plug in, switch on, and start playing with. Meanwhile, others prefer to find the damaged examples and nurse them back to health. [polymatt] can count himself in that category, as evidenced by his heroic rescue of an 1993 IBM ThinkPad Tablet.

The tablet came to [polymatt] in truly awful condition. Having been dropped at least once, the LCD screen was cracked, the case battered, and all the plastics were very much the worse for wear. Many of us would consider it too far gone, especially considering that replacement parts for such an item are virtually unobtainable. And yet, [polymatt] took on the challenge nonetheless.

Despite its condition, there were some signs of life in the machine. The pen-based touch display seemed to respond to the pen itself, and the backlight sort of worked, too. Still, with the LCD so badly damaged, it had to be replaced. Boggling the mind, [polymatt] was actually able to find a 9.4″ dual-scan monochrome LCD that was close enough to sort-of fit, size-wise. To make it work, though, it needed a completely custom mount to fit with the original case and electromagnetic digitizes sheet. From there, there was plenty more to do—recapping, recabling, fixing the batteries, and repairing the enclosure including a fresh set of nice decals.

The fact is, 1993 IBM ThinkPad Tablets just don’t come along every day. These rare specimens are absolutely worth this sort of heroic restoration effort if you do happen to score one on the retro market. Video after the break.

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