A Pentium In Your Hand

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

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

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

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

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.

Schematic diagram of part of RAM

Making RAM For A TMS9900 Homebrew Computer

Over on YouTube [Usagi Electric] shows us how to make RAM for the TMS9900.

He starts by remarking that the TI-99/4A computer is an excellent place to start if you’re interested in getting into retro-computing. Particularly there are a lot of great resources online, including arcadeshopper.com and the AtariAge forums.

The CPU in the TI-99 is the TMS9900. As [Usagi Electric] explains in the video this CPU only has a few registers and most actual “registers” are actually locations in RAM. Because of this you can’t do much with a TMS9900 without RAM attached. So he sets about making some RAM for his homebrew TMS9900 board. He uses Mitsubishi M58725P 16 kilobit (2 kilobyte) static RAM integrated circuits; each has 11 address lines and 8 data lines, so by putting two side-by-side we get support for 16-bit words. Using six M58725Ps, in three pairs, we get 6 kilowords (12 kilobytes).

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A photo of the MMD-1 on the workbench.

Restoring The E&L MMD-1 Mini-Micro Designer Single-Board Computer From 1977

Over on YouTube [CuriousMarc] and [TubeTimeUS] team up for a multi-part series E&L MMD-1 Mini-Micro Designer Restoration.

The E&L MMD-1 is a microcomputer trainer and breadboard for the Intel 8080. It’s the first ever single-board computer. What’s more, they mention in the video that E&L actually invented the breadboard with the middle trench for the ICs which is so familiar to us today; their US patent 228,136 was issued in August 1973.

The MMD-1 trainer has support circuits providing control logic, clock, bus drivers, voltage regulator, memory decoder, memory, I/O decoder, keyboard encoder, three 8-bit ports, an octal keyboard, and other support interconnects. They discuss in the video the Intel 1702 which is widely accepted as the first commercially available EPROM, dating back to 1971.

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