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30 Articles

Modern Graphics Via DisplayLink For Your ISA-Era PC

May 31, 2026 by 13 Comments

The monitors used on older computers are now becoming difficult to find, as we doubt anything for MDA, CGA, Hercules, or EGA has been manufactured in decades. Even VGA, though there are plenty of surplus flat panels to be found, is not as ubiquitous as it once was. Where does that leave the retrocomputing enthusiast with an ISA PC and no screen? Perhaps [Ian Hanschen] has the answer with the PicoGraph, an ISA-to-USB-to-Displaylink adapter.

In hardware terms, it’s using a PicoMEM, a more general-purpose ISA card for emulating cards with a Pi Pico. The Pico hosts a USB DisplayLink adapter, which can connect to the screen of your choice. The software on the PicoMEM does the heavy lifting and provides MDA, Herc, EGA, and VGA support, as well as support for one of the 1990s Cirrus Logic SVGA chipsets. And yes, it appears to work with DOOM.

The practice of using 2020s microcontrollers to lend functionality to retrocomputers has revolutionised the art. We’ve seen many, with one of the more recent being a minimap add-on for an 8-bit Sinclair Spectrum.

IBM Made A Sound Card? Who Knew!

February 9, 2026 by 17 Comments

Even in a field you think you know intimately, the Internet still has the power to surprise. Sound cards of the 1990s might not be everyone’s specialist subject, but since the CD-ROM business provided formative employment where this is being written, it’s safe to say that a lot of tech from that era is familiar. It’s a surprise then when along comes [DOS Storm] with a new one. The IBM Mwave was the computer giant’s offering back in the days when they were still pushing forward in the PC space, and sadly for them it turned out to be a commercial disaster.

The king of the sound cards in the ’90s was the SoundBlaster 16, which other manufacturers cloned directly. Not IBM of course, who brought their own Mwave DSP chip to the card, using it as both the sound card and the engine behind an on-board dial-up modem. This appears to have been its undoing, because aside from its notoriously flaky drivers, using both sound and modem at the same time just wasn’t a pleasant experience. To compound the problem, Big Blue resorted to trying to bury the problem with NDAs rather than releasing better drivers, so unsurprisingly it faded from view. Perhaps the reason it was unfamiliar here had something to do with it not being sold in Europe, but given that the chipset found its way into ’90s ThinkPads, we’d have expected to have seen something of it.

In the video below the break he introduces the card, and with quite some trouble gets it working. There are several demos of period games which sound a little scratchy, but we can’t judge from this whether they’d have sounded better on the Creative card. If you’d like to immerse yourself in the folly of ’90s multimedia, have a little bit of Hackaday scribe reminiscing.

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Benchmarking Chinese CPUs

November 26, 2025 by 25 Comments

When it comes to PCs, Westerners are most most familiar with x86/x64 processors from Intel and AMD, with Apple Silicon taking up a significant market share, too. However, in China, a relatively new CPU architecture is on the rise. A fabless semiconductor company called Loongson has been producing chips with its LoongArch architecture since 2021. These chips remain rare outside China, but some in the West have been benchmarking them.

[Daniel Lemire] has recently blogged about the performance of the Loongson 3A6000, which debuted in late 2023. The chip was put through a range of simple benchmarking tests, involving float processing and string transcoding operations. [Daniel] compared it to the Intel Xeon Gold 6338 from 2021, noting the Intel chip pretty much performed better across the board. No surprise given its extra clock rate. Meanwhile, the gang over at [Chips and Cheese] ran even more exhaustive tests on the same chip last year. The Loongson was put through typical tasks like  compressing archives and encoding video. The outlet came to the conclusion that the chip was a little weaker than older CPUs like AMD’s Zen 2 line and Intel’s 10th generation Core chips. It’s also limited as a four-core chip compared to modern Intel and AMD lines that often start at 6 cores as a minimum.

If you find yourself interested in Loongson’s product, don’t get too excited. They’re not exactly easy to lay your hands on outside of China, and even the company’s own website is difficult to access from beyond those shores. You might try reaching out to Loongson-oriented online communities if you seek such hardware.

Different CPU architectures have perhaps never been more relevant, particularly as we see the x86 stalwarts doing battle with the rise of desktop and laptop ARM processors. If you’ve found something interesting regarding another obscure kind of CPU, don’t hesitate to let the tipsline know!

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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A Walk Down PC Video Card Memory Lane

September 28, 2025 by 30 Comments

These days, video cards are virtually supercomputers. When they aren’t driving your screen, they are decoding video, crunching physics models, or processing large-language model algorithms. But it wasn’t always like that. The old video cards were downright simple. Once PCs gained more sophisticated buses, video cards got a little better. But hardware acceleration on an old-fashioned VGA card would be unworthy of the cheapest burner phone at the big box store. Not to mention, the card is probably twice the size of the phone. [Bits and Bolts] has a look at several old cards, including a PCI version of the Tseng ET4000, state-of-the-art of the late 1990s.

You might think that’s a misprint. Most of the older Tseng boards were ISA, but apparently, there were some with the PCI bus or the older VESA local bus. Acceleration here typically meant dedicated hardware for handling BitBlt and, perhaps, a hardware cursor.

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Computer Has One Instruction, Many Transistors

September 20, 2025 by 22 Comments

There’s always some debate around what style of architecture is best for certain computing applications, with some on the RISC side citing performance per watt and some on the CISC side citing performance per line of code. But when looking at instruction sets it’s actually possible to eliminate every instruction except one and still have a working, Turing-complete computer. This instruction is called subleq or “subtract and branch if less-than or equal to zero“. [Michael] has built a computer that does this out of discrete components from scratch.

We’ll save a lot of the details of the computer science for [Michael] or others to explain, but at its core this is a computer running with a 1 kHz clock with around 700 transistors total. Since the goal of a single-instruction computer like this is simplicity, the tradeoff is that many more instructions need to be executed for equivalent operations. For this computer it takes six clock cycles to execute one instruction, for a total of about 170 instructions per second. [Michael] also created an assembler for this computer, so with an LCD screen connected and mapped to memory he can write and execute a simple “hello world” program just like any other computer.

[Michael] does note that since he was building this from Logisim directly he doesn’t have a circuit schematic, but due to some intermittent wiring issues might have something in the future if he decides to make PCBs for this instead of using wire on a cardboard substrate. There’s plenty of other information on his GitHub page though. It’s a unique project that gets to the core of what’s truly needed for a working computer. There are a few programming languages out there that are built on a similar idea.

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VIC-20 Gets ISA Slot, Networking

August 26, 2025 by 22 Comments

There are few computing collapses more spectacular than the downfall of Commodore, but its rise as a home computer powerhouse in the early 80s was equally impressive. Driven initially by the VIC-20, this was the first home computer model to sell over a million units thanks to its low cost and accessibility for people outside of niche markets and hobbyist communities.

The VIC-20 would quickly be eclipsed by the much more famous Commodore 64, but for those still using these older machines there are a few tweaks to give it some extra functionality it was never originally designed for like this build which gives it an ISA bus.

To begin adapting the VIC-20 to the ISA standard, [Lee] built a fixed interrupt line handled with a simple transistor circuit. From there he started mapping memory and timing signals. The first attempt to find a portion of memory to use failed as it wasn’t as unused as he had thought, but eventually he settled on using the I/O area instead although still had to solve some problems with quirky ISA timing. There’s also a programmable logic chip which was needed to generate three additional signals for proper communication.

After solving some other issues around interrupts [Lee] was finally able to get the ISA bus working, specifically so he could add a 3Com networking card and get his VIC-20 on his LAN. Although the ISA bus has since gone out of fashion on modern computers, if you still have a computer with one (or build one onto your VIC-20), it is a surprisingly versatile expansion port.

Thanks to [Stephen] for the tip!