A Walk Down PC Video Card Memory Lane

September 28, 2025 by Al Williams 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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NEC V20: The Original PC Processor Upgrade

September 27, 2025 by Jenny List 17 Comments

In the early 1980s, there was the IBM PC, with its 4.77 MHz Intel 8088 processor. It was an unexpected hit for the company, and within a few years there were a host of competitors. Every self-respecting technology corporation wanted a piece of the action including processor manufacturers, and among those was NEC with their V20 chip and its V30 sibling. From the outside they were faster pin-compatible 8088 and 8086 clones, but internally they could also run both 8080 and 80186 code. [The Silicon Underground] has a look back at the V20, with some technical details, history, and its place as a PC upgrade.

For such a capable part it’s always been a surprise here that it didn’t take the world by storm, and the article sheds some light on this in the form of an Intel lawsuit that denied it a critical early market access. By the time it was available in quantity the PC world had moved on from the 8088, so we saw it in relatively few machines. It was a popular upgrade for those in the know back in the day though as it remains in 2025, and aside from its immediate speed boost there are a few tricks it lends to a classic PC clone. The version of DOS that underpinned Windows 95 won’t run on an 8086 or 8088 because it contains 8016 instructions, but a V20 can run it resulting in a much faster DOS experience. One to remember, if an early PC or clone cones your way.

Hungry for the good old days of DOS? You don’t need to find 80s hardware for that.

First Transistor Computer Reborn

September 21, 2025 by Al Williams 15 Comments

Ok, we’ll admit it. If you asked us what the first transistorized computer was, we would have guessed it was the TC from the University of Manchester. After all, Dr. Wilkes and company were at the forefront and had built Baby and EDSAC, which, of course, didn’t use transistors. To be clear, we would have been guessing, but what we didn’t know at all was that the TC, with its magnetic drums and transistors in 1955, had a second life as a commercial product from Metropolitan-Vickers, called the Metrovick 950. [Nina Kalinina] has a simulator inspired by the old machine.

The code is in Python, and you can find several programs to run on the faux machine, including the venerable lunar lander. If you haven’t heard of the Metrovick, don’t feel bad. Oral histories say that only six or seven were ever built, and they were used internally within the company.

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A Serial Mouse For A Homebrew 8-bit Computer

September 21, 2025 by Al Williams 2 Comments

[Too Many Wires] has a custom computer he’s building. He wanted a mouse, but USB is a bit of a stretch for the fledgling computer. We might have opted for PS/2, but he went for something even older: a serial mouse connected with a DE-9 (colloquially, a DB-9). Check it out in his recent video update on the project below.

Don’t remember serial mice? They were very common many years ago, and apparently, you can still buy new ones, which makes you wonder what people are doing with them. If you are an old hand at serial, you’ll immediately know why he couldn’t get it to work at first. If you haven’t worked with RS-232 gear before, you’ll learn a lot.

The protocol is simple enough, and you can read the code or find plenty of old documents. He’s using a UART chip, which offloads the CPU. However, the PS/2 mice are very easy to work with directly, and you could skip the +/- 12V RS-232 and other issues.

Either way, however, using an RS-232 or PS/2 mouse in a project is relatively straightforward. You might not think you need a mouse, but don’t forget, they are really accurate two-axis sensors. An optical mouse on a motion table, for example, could be worth something.

The computer is based on [Ben Eater]’s design, if you want more details on that. Can’t decide between RS-232 and PS/2? You don’t have to.

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Imagining The CPS-1: An Early 70s 4-bit Microcomputer From Canada

September 19, 2025 by John Elliot V 4 Comments

[Michael Gardi] wrote in to let us know about his project: CPS-1: Imagining An Early 70s 4-bit Microcomputer.

The CPS-1 was the first Canadian microprocessor-based computer. It was built by Microsystems International Ltd. (MIL) in Ottawa between 1972 and 1973 and it is unknown how many were made and in what configurations. The CPS-1 supported a 12-bit address bus and a 4-bit data bus. MIL also developed the supporting hardware including RAM. The processor was called the MIL 7114.

[Michael] worked in collaboration with [Zbigniew Stachniak] from York University Computer Museum. [Zbigniew] had developed a MIL CPS-1 Emulator and [Michael]’s job was to implement a front panel hardware interface for the emulator which runs on a Raspberry Pi. The only complication: there are no remaining CPS-1 computers, and no known photographs, so no one can say for sure what a real front panel might have looked like!

With a bit of guess work and 3D printing, as well as some inspiration from contemporaneous hardware such as the DEC PDP-11, [Michael] came up with an implementation. He used an IO extender HAT which adds 32 IO pins to the existing Pi GPIO pins that are accessible via an 3-wire I2C interface. This was enough hardware to support the 26 switches and 29 LEDs on the panel. There’s a brief demo of the custom printed switches in the video embedded below.

If you’re interested in old school 4-bit tech you might also like to check out 4-bit Single Board Computer Based On The Intel 4004 Microprocessor.

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A GEM Of A Desktop Environment

September 18, 2025 by Jenny List 25 Comments

Desktop environments are the norm as computer interfaces these days, but there was once a time when they were a futuristic novelty whose mere presence on a computer marked it out as something special. In the early 1980s you could buy an expensive but very fancy Mac from Apple, while on the PC there were early Windows versions, and GEM from Digital Research. It’s something of a footnote here in 2025, and some insight as to why comes from [Programming at the right level] with a retrospective on the software.

Coming from the perspective of an Atari user whose ST shipped with a version of GEM, it tracks the projects from its earliest roots with a Xerox employee, through development to launch on the PC and Atari ST. We learn about an Apple legal threat that resulted in the hobbled interface many of us remember from later GEM versions, and about the twists and turns in its path before the final dissolution of DR in the early 1990s.

From 2025 it’s clear that Windows won the PC desktop battle not by being special but by being the default; when GEM was an add-on extra it would have been a tough sell. The software was eventually made open-source by the eventual owner of the DR assets, Caldera (when they weren’t trying to torpedo Linux, presumably), and can be run today on FreeDOS.

GEM header image: Rolf Hartmann, CC BY-SA 3.0.

Forgotten Internet: The Story Of Email

September 17, 2025 by Al Williams 25 Comments

It is a common occurrence in old movies: Our hero checks in at a hotel in some exotic locale, and the desk clerk says, “Ah, Mr. Barker, there’s a letter for you.” Or maybe a telegram. Either way, since humans learned to write, they’ve been obsessed with getting their writing in the hands of someone else. Back when we were wondering what people would do if they had a computer in their homes, most of us never guessed it would be: write to each other. Yet that turned out to be the killer app, or, at least, one of them.

What’s interesting about the hotel mail was that you had to plan ahead and know when your recipient would be there. Otherwise, you had to send your note to their home address, and it would have to wait. Telegrams were a little better because they were fast, but you still had to know where to send the message.

Early Days

An ad from the 1970s with a prominent Telex number

In addition to visiting a telegraph office, or post office, to send a note somewhere, commercial users started wanting something better at the early part of the twentieth century. This led to dedicated teletype lines. By 1933, though, a network of Teletype machines — Telex — arose. Before the Internet, it was very common for a company to advertise its Telex number — or TWX number, a competing network from the phone company and, later, Western Union — if they dealt with business accounts.

Fax machines came later, and the hardware was cheap enough that the average person was slightly more likely to have a fax machine or the use of one than a Telex.

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