Retrocomputing

1433 Articles

Damaged Pocket Computer Becomes Portable Linux Machine

November 28, 2025 by 41 Comments

The Sharp PC-G801 was an impressive little pocket computer when it debuted in 1988. However, in the year 2025, a Z80-compatible machine with just 8 kB of RAM is hardly much to get excited about. [shiura] decided to take one of these old machines and upgrade it into something more modern and useful.

The build maintains the best parts of the Sharp design — namely, the case and the keypad. The original circuit board has been entirely ripped out, and a custom PCB was designed to interface with the membrane keypad and host the new internals. [shiura] landed on the Raspberry Pi Zero 2W to run the show. It’s a capable machine that runs Linux rather well and has wireless connectivity out of the box. It’s paired with an ESP32-S3 microcontroller that handles interfacing all the various parts of the original Sharp hardware. It also handles the connection to the 256×64 OLED display. The new setup can run in ESP32-only mode, where it acts as a classic RPN-style calculator. Alternatively, the Pi Zero can be powered up for a full-fat computing experience.

The result of this work is a great little cyberdeck that looks straight out of the 1980s, but with far more capability. We’ve seen a few of these old pocket computers pop up before, too.

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A Couple Of New DOS PCs Appear

November 23, 2025 by 93 Comments

An interesting trend over the last year or two has been the emergence of modern retrocomputer PCs, recreations of classic PC hardware from back in the day taking advantage of modern parts alongside the venerable processors. These machines are usually very well specified for a PC from the 1980s, and represent a credible way to run your DOS or early Windows software on something close to the original. [CNX Software] has news of a couple of new ones from the same manufacturer in China, one sporting a 386sx and the other claiming it can take either an 8088 or an 8086.

Both machines use the same see-through plastic case, screen, and keyboard, and there are plenty of pictures to examine the motherboard. There are even downloadable design files, which is an interesting development. They come with a removable though proprietary looking VGA card bearing a Tseng Labs ET4000, a CF card interface, a USB port which claims to support disk drives, a sound card, the usual array of ports, and an ISA expansion for which a dock is sold separately. The battery appears to be a LiPo pouch cell of some kind.

If you would like one they can be found through the usual channels for a not-outrageous price compared to similar machines. We can see the attraction, though maybe we’ll stick with an emulator for now. If you’d like to check out alternatives we’ve reported in the past on similar 8088 and 386sx computers.

Retrotechtacular: Computers In Schools? 1979 Says Yes

November 23, 2025 by 28 Comments

The BBC wanted to show everyone how a computer might be used in schools. A program aired in 1979 asks, “Will Computers Revolutionise Education?” There’s vintage hardware and an appearance of PILOT, made for computer instructions.

Using PILOT looks suspiciously like working with a modern chatbot without as much AI noise. The French teacher in the video likes that schoolboys were practicing their French verb conjugation on the computer instead of playing football.

If you want a better look at hardware, around the five-minute mark, you see schoolkids making printed circuit boards, and some truly vintage oscilloscope close-ups. There are plenty of tiny monitors and large, noisy printing terminals.

You have to wonder where the eight-year-olds who learned about computers in the video are today, and what kind of computer they have. They learned binary and the Towers of Hanoi. Their teacher said the kids now knew more about computers than their parents did.

As a future prediction, [James Bellini] did pretty well. Like many forecasters, he almost didn’t go far enough, as we look back almost 50 years. Sure, Prestel didn’t work out as well as they thought, dying in 1994. But he shouldn’t feel bad. Predicting the future is tough. Unless, of course,  you are [Arthur C. Clarke].

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How To Use That Slide Rule

November 21, 2025 by 30 Comments

You have that slide rule in the back of the closet. Maybe it was from your college days. Maybe it was your Dad’s. Honestly. Do you know how to use it? Really? All the scales? That’s what we thought. [Amen Zwa, Esq.] not only tells you how slide rules came about, but also how to use many of the common scales. You can also see his collection and notes on being a casual slide rule collector and even a few maintenance tips.

The idea behind these computing devices is devilishly simple. It is well known that you can reduce a multiplication operation to addition if you have a table of logarithms. You simply take the log of both operands and add them. Then you do a reverse lookup in the table to get the answer.

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Commodore’s Most Popular Computer Gets DOOM-style Shooter

November 21, 2025 by 45 Comments

When people talk about the lack of a DOOM being the doom Commodore home computers, they aren’t talking about the C64, which was deep into obsolescence when demon-slaying suddenly became the minimal requirement for all computing devices. That didn’t stop [Kamil Wolnikowski] and [Piotr Kózka] from hacking together Grey a ray-cast first-person shooter for the Commodore 64.

Grey bares more than a passing resemblance to id-software’s most-ported project. It apparently runs at 16 frames per second on a vanilla C64 — no super CPU required. The secret to the speedy game play is the engine’s clever use of the system’s color mapping functionality: updating color maps is faster than redrawing the screen. Yeah, that makes for rather “blockier” graphics than DOOM, but this is running on a Commodore 64, not a 386 with 4 MB of RAM. Allowances must be made. Come to think of it, we don’t recall DOOM running this smooth on the minimum required hardware — check out the demo video below and let us know what you think.

The four-level demo currently available is about 175 kB, which certainly seems within the realms of possibility for disk games using the trusty 1541. Of course nowadays we do have easier ways to get games onto our vintage computers.

If you’re thinking about Commodore’s other home computer, it did eventually get a DOOM-clone. Continue reading “Commodore’s Most Popular Computer Gets DOOM-style Shooter” →

A Paper Caper: The Hole Data

November 20, 2025 by 26 Comments

Since the dawn of computers, we’ve tried different ways to store data. These days, you grab data over the network, but you probably remember using optical disks, floppies, or, more recently, flash drives to load something into your computer. Old computers had to use a variety of methods, such as magnetic tape. But many early computers used some technology that existed from the pre-computer era, like punched cards or, as [Anthony Francis-Jones] shows us, paper tape.

Paper tape was common in TeleType machines and some industrial applications. In fact, as early as 1725, looms could use paper tape, which would eventually lead to punched cards. For computers, there were two common variations that differed in how many holes were punched across the tape: 5 or 8. There was also a small sprocket hole that allowed a gear to move the tape forward through a reader.

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[Usagi Electric] and his home brew computer

TMS9900-based Home Brew Computer

November 17, 2025 by 3 Comments

[Usagi Electric] is known for minicomputers, but in a recent video, he shows off his TMS9900-based homebrew computer. The TMS9900 CPU was an early 16-bit CPU famously used in the old TI-99/4A computer, but as the video points out, it wasn’t put to particularly good use in the TI-99/4A because its RAM was hidden behind an inefficient interface and it didn’t leverage its 16-bit address space.

The plan is for this computer to have 2K words of ROM, 6K words of RAM, and three serial lines: one for the console terminal, another for a second user console terminal, and the third for access to a tape drive.

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