Retrocomputing

1452 Articles

BIOS Detectives Find Ghost Of Previously Unknown PC

November 8, 2025 by 24 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!

Spectravideo Computers Get A Big Upgrade

November 5, 2025 by 2 Comments

Spectravideo is not exactly the most well-known microcomputer company, but they were nevertheless somewhat active in the US market from 1981 to 1988. Their computers still have a fanbase of users and modders. Now, as demonstrated by [electricadventures], you can actually upgrade your ancient Spectravideo machine with some modern hardware.

The upgrade in question is the SVI-3×8 PicoExpander from [fitch]. It’s based on a Raspberry Pi Pico 2W, and is built to work with the Spectravideo 318 and 328 machines. If you’re running a 328, it will offer a full 96kB of additional RAM, while if you’re running a 318, it will add 144 kB more RAM and effectively push the device up to 328 spec. It’s also capable of emulating a pair of disk drives or a cassette drive, with saving and loading images possible over Wi-Fi.

It’s worth noting, though, that the PicoExpander pushes the Pico 2W well beyond design limits, overclocking it to 300 MHz (versus the original 150 MHz clock speed). The makers note it is “bleeding edge” hardware and that it may not last as long as the Spectravideo machines themselves.

Design files are available on Github if you want to spin up your own PicoExpander, or you can just order an assembled version. We’ve seen a lot of other neat retrocomputer upgrades built around modern hardware, too. Video after the break.

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A Pentium In Your Hand

November 5, 2025 by 8 Comments

Handheld computers have become very much part of the hardware hacker scene, as the advent of single board computers long on processor power but short on power consumption has given us the tools we need to build them ourselves. Handheld retrocomputers face something of an uphill struggle though, as many of the components are over-sized, and use a lot of power. [Changliang Li] has taken on the task though, putting an industrial Pentium PC in a rather well-designed SLA printed case.

Aside from the motherboard there’s a VGA screen, a CompactFlash card attached to the IDE interface, and a Logitech trackball. As far as we can see the power comes from a USB-C PD board, and there’s a split mechanical keyboard on the top side. It runs Windows 98, and a selection of peak ’90s games are brought out to demonstrate.

We like this project for its beautiful case and effective use of parts, but we’re curious whether instead of the Pentium board it might have been worth finding a later industrial PC to give it a greater breadth of possibilities, there being few x86 SBCs. Either way it would have blown our minds back in ’98, and we can see it’s a ton of fun today. Take a look at the machine in the video below the break.

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Adding ISA Ports To Modern Motherboards

November 3, 2025 by 23 Comments

Modern motherboards don’t come with ISA slots, and almost everybody is fine with that. If you really want one, though, there are ways to get one. [TheRasteri] explains how in a forum post on the topic.

Believe it or not, some post-2010 PC hardware can still do ISA, it’s just that the slots aren’t broken out or populated on consumer hardware. However, if you know where to look, you can hack in an ISA hookup to get your old hardware going. [TheRasteri] achieves this on motherboards that have the LPC bus accessible, with the use of a custom PCB featuring the Fintek F85226 LPC-to-ISA bridge. This allows installing old ISA cards into a much more modern PC, with [TheRasteri] noting that DMA is fully functional with this setup—important for some applications. Testing thus far has involved a Socket 755 motherboard and a Socket 1155 motherboard, and [TheRasteri] believes this technique could work on newer hardware too as long as legacy BIOS or CSM is available.

It’s edge case stuff, as few of us are trying to run Hercules graphics cards on Windows 11 machines or anything like that. But if you’re a legacy hardware nut, and you want to see what can be done, you might like to check out [TheRasteri’s] work over on Github. Video after the break.

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MCE Blaster Translates TTL For Modern(ish) Monitors

November 3, 2025 by 15 Comments

VGA isn’t much used anymore, but it’s not hard to get a hold of monitors with that input. How about the older standards like EGA, CGA, or MDA? Well, it’s good luck on eBay or at the recycling yard to get a period-appropriate monitor, but the bulky, fragile CRTs seem to have been less likely to survive than computers that drove them. That’s what [Scrap Computer]’s MCE Blaster is for: it sits betwixt the retrocomputer’s TTL output and the VGA input of a (more) modern monitor, be it CRT or LCD.

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Multitasking On The Humble Z80 CPU

November 1, 2025 by 32 Comments

Multitasking is something we take for granted these days. Just about every computer we use, from our desktops to our phones, is capable of multitasking. It might sound silly to implement multitasking on lower-spec machines from many decades ago, given their limited resources, but it can be done, as [bchiha] demonstrates on a Z80-based machine.

[bchiha] has achieved pre-emptive multitasking on the TEC-1G Z80 computer, a modern reimagining of the classic Talking Electronics TEC-1 from the 1980s.  The proof of concept code allows running up to eight separate tasks at once. Task switching runs on interrupts, triggered at approximately 50 Hz. When an interrupt fires, the CPU registers are transferred onto that task’s stack, and the next task’s stack is swapped to the stack pointer to allow execution of the new task to proceed. There is an overhead, of course, with [bchiha] noting that the task swapping routine itself takes about 430 clock cycles to run in between tasks.

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The most exciting search engine 68k can handle.

There’s Nothing Boring About Web Search On Retro Amigas

October 31, 2025 by 23 Comments

Do you have a classic Amiga computer? Do you want to search the web with iBrowse, but keep running into all that pesky modern HTML5 and HTTPS? In that case, [Nihirash] created BoingSearch.com just for you!

BoingSearch was explicitly inspired by [ActionRetro]’s FrogFind search portal, and works similarly in practice. From an end-user perspective, they’re quite similar: both serve as search engines and strip down the websites listed by the search to pure HTML so old browsers can handle it.

Boing search in its natural habitat, iBrowse on Amiga.

The biggest difference we can see betwixt the two is that FrogFind will link to images while BoingSearch either loads them inline or strips them out entirely, depending on the browser you test with and how the page was formatted to begin with. (Ironically, modern Firefox doesn’t get images from BoingSearch’s page simplifier.) BoingSearch also gives you the option of searching with DuckDuckGo or Google via the SerpAPI, though note that poor [Nihirash] is paying out-of-pocket for google searches.

BoingSearch is explicitly aimed at the iBrowse browser for late-stage Amigas, but should work equally well with any modern browser. Apparently this project only exists because FrogFind went down for a week, and without the distraction of retrocomptuer websurfing, [Nihirash] was able to bash out his own version from scratch in Rust. If you want to self-host or see how they did it, [Nihirash] put the code on GitHub under a donationware license.

If you’re scratching your head why on earth people are still going on about Amiga in 2025, here’s one take on it.