Retrocomputing

1441 Articles

You Can Make Your Own Floppy Drive Cleaning Disks

August 1, 2025 by 11 Comments

Once upon a time, you could buy floppy drive cleaning disks at just about any stationary or computer store. These days, they’re harder to find. If you want to build one yourself, though, you might do well to follow [Gammitin]’s fine example.

[Gammitin] has been down this road before, having built head cleaning disks before. This time, a US patent was the inspiration. It basically indicated that the spinning cleaning disc inside should be made of spunbonded polyester or spunbonded olefin (such as Dupont Tyvek)—so those materials were sought out.

The project began with [Gammitin] disassembling a standard floppy disk down to its bare components. The spindle was then separated from the magnetic platter, and refitted with a disc of Tyvek material using super glue. The disk housing was then glued back together with more super glue, and labelled as a “Floppy Cleaning Disk.” Using the disk is as simple as putting a few drops of isopropyl alcohol on the Tyvek material, and inserting it into a drive. [Gammitin] tested it with an old Olivetti machine, and found it cleaned up the heads nicely.

Sometimes, when a commercial product ceases to exist, you can just make your own at home. This is a great example of that ethos. If you’re cooking up your own tools and accessories to keep your old machines running, we’d love to hear all about it on the tipsline!

A Proper Computer For A Dollar?

August 1, 2025 by 49 Comments

When a tipster came to us with the line “One dollar BASIC computer”, it intrigued us enough to have a good look at [Stan6314]’s TinyBasRV computer. It’s a small PCB that forms a computer running BASIC. Not simply a microcontroller with a serial header, this machine is a fully functioning BASIC desktop computer that takes a PS/2 keyboard and a VGA monitor. Would that cheap price stand up?

The board uses a CH32 microcontroller, a RISC-V part that’s certainly very cheap indeed and pretty powerful, paired with an I2C memory chip for storage. The software is TinyBASIC. There’s some GPIO expandability and an I2C bus, and it’s claimed it can run in headless mode for a BASIC program to control things.

We haven’t added up all the parts in the BoM to check, but even if it’s not a one dollar computer it must come pretty close. We can see it could make a fun project for anyone. It’s certainly not the only small BASIC board out there, it’s got some competition.

Thanks [Metan] for the tip.

Soldered RAM Upgrades Finally Available For Mac-PPC

July 30, 2025 by 8 Comments

In the retrocomputing world, [DosDude1] is a name spoken with more than a little respect. He’s back again with a long-awaited hack for PowerPC Macintosh: soldered RAM upgrades!

[DosDude1] is no stranger to soldering his way to more storage– upgrading the SSD on an M4 Mac Mini, or doubling  the VRAM on an old GPU. For a PPC Mac, though, it is not enough just to solder more RAM onto the board; if that’s all it was, we’d have been doing it 20 years ago. Once the RAM is in place, you have to have some way to make sure the computer knows the RAM is in place. For a WinTel machine, getting that information to the BIOS can be as easy as plugging in the right resistors. Continue reading “Soldered RAM Upgrades Finally Available For Mac-PPC” →

Learn Computing? Head For MonTana!

July 28, 2025 by 10 Comments

We’ve often thought that it must be harder than ever to learn about computers. Every year, there’s more to learn, so instead of making the gentle slope from college mainframe, to Commodore 64, to IBM PC, to NVidia supercomputer, you have to start at the end. But, really, you don’t. You can always emulate computers from simpler times, and even if you don’t need to, it can be a lot of fun.

That’s the idea behind the MonTana mini-computer. It combines “…ideas from the PDP-11, MIPS, Scott CPU, Game Boy, and JVM to make a relatively simple 16-bit computer…”

The computer runs on Java, so you can try it nearly anywhere. The console is accessed through a web browser and displays views of memory, registers, and even something that resembles a Game Boy screen. You’ll need to use assembly language until you write your own high-level language (we’d suggest Forth). There is, however, a simple operating system, MTOS.

This is clearly made for use in a classroom, and we’d love to teach a class around a computer like this. The whole thing reminds us of a 16-bit computer like the PDP-11 where everything is a two-byte word. There are only 4K bytes of memory (so 2K words). However, you can accomplish a great deal in that limited space. Thanks to the MTOS API, you don’t have to worry about writing text to the screen and other trivia.

It looks like fun. Let us know what you’ll use it for. If you want to go down a level, try CARDIAC. Or skip ahead a little, and teach kids QBasic.

A History Of Pong

July 28, 2025 by 8 Comments

Today, creating a ground-breaking video game is akin to making a movie. You need a story, graphic artists, music, and more. But until the middle of the 20th century, there were no video games. While several games can claim to be the “first” electronic or video game, one is cemented in our collective memory as the first one we’d heard of: Pong.

The truth is, Pong wasn’t the first video game. We suspect that many people might have had the idea, but Ralph Baer is most associated with inventing a practical video game. As a young engineer in 1951, he tried to convince his company to invest in games that you could play on your TV set. They didn’t like the idea, but Ralph would remember the concept and act on it over a decade later.

But was it really the first time anyone had thought of it? Perhaps not. Thomas Goldsmith Jr. and Estle Ray Mann filed a patent in 1947 for a game that simulated launching missiles at targets with an oscilloscope display. The box took eight tubes and, being an oscilloscope, was a vector graphic device. The targets were physical dots on a screen overlay. These “amusement devices” were very expensive, and they only produced handmade prototypes.

Continue reading “A History Of Pong” →

Commodore 64 On New FPGA

July 28, 2025 by 19 Comments

When it comes to getting retro hardware running again, there are many approaches. On one hand, the easiest path could be to emulate the hardware on something modern, using nothing but software to bring it back to life. On the other, many prefer to restore the original hardware itself and make sure everything is exactly as it was when it was new. A middle way exists, though, thanks to the widespread adoption of FPGAs which allow for programmable hardware emulation and [Jo] has come up with a new implementation of the Commodore 64 by taking this path.

The project is called the VIC64-T9K and is meant as a proof-of-concept that can run the Commodore 64’s VIC-II video chip alongside a 6502 CPU on the inexpensive Tang Nano 9k FPGA. Taking inspiration from the C64_MiSTer project, another FPGA implementation of the C64 based on the DE10-Nano FPGA, it doesn’t implement everything an original Commodore system would have had, but it does provide most of the core hardware needed to run a system. The project supports HDMI video with a custom kernel, and [Jo] has used it to get a few demos running including sprite animations.

Built with a mix of Verilog and VHDL, it was designed as a learning tool for [Jo] to experiment with the retro hardware, and also brings a more affordable FPGA board to the table for Commodore enthusiasts. If you’re in the market for something with more of the original look and feel of the Commodore 64, though, this project uses the original case and keyboard while still using an FPGA recreation for the core of the computer.

Comprehensive Test Set Released For The Intel 80286

July 24, 2025 by 23 Comments

Remember the 80286? It was the sequel to the 8086, the chip that started it all, and it powered a great number of machines in the early years of the personal computing revolution. It might not be as relevant today, but regardless, [Daniel Balsom] has now released a comprehensive test suite for the ancient chip. (via The Register)

The complete battery of tests are available on Github, and were produced using a Harris N80C286-12 from 1986. “The real mode test suite contains 326 instruction forms, containing nearly 1.5 million instruction executions with over 32 million cycle states captured,” Daniel explains. “This is fewer tests than the previous 8088 test suite, but test coverage is better overall due to improved instruction generation methods.” For now, the tests focus on the 286 running in real mode. There are no “unreal” or protected mode tests, but [Daniel] aims to deliver the in the future.

[Daniel] uses the tests with the ArduinoX86, a platform that uses the microcontroller to control and test old-school CPUs. The tests aid with development of emulators like [Daniel’s] own MartyPC, by verifying the CPU’s behavior in a cycle-accurate way.

We’ve explored some secrets of the 286 before, too. If you’ve been doing your own digging into Intel’s old processors, or anyone else’s for that matter, don’t hesitate to notify the tipsline.

[Thanks to Stephen Walters for the tip!]