Retrocomputing

782 Articles

BBC Master 128 Revealed

May 28, 2023 by 2 Comments

[Adrian] comments that the BBC Master 128 is a rare 8-bit computer, and we agree — we couldn’t remember hearing about that particular machine, although the BBC series is quite familiar. The machine has a whopping 128 K of RAM, quite a bit for those days. It also had a 6502 variant known as the 65C12, which has an extra pin compared to a 6502 and doesn’t use the same clock arrangement. A viewer sent him one of these machines, which apparently was used in the BBC studios. You can see this rare beauty in the video below.

The computer has a very nice-looking keyboard that includes a number pad. There are also expansion ports for printers and floppy disk drives. It has some similarities to a standard BBC computer but has a number of differences externally and internally.

Of course, we were waiting for the teardown about 15 minutes in. There were some corroded batteries but luckily, they didn’t do much damage. The power supply had a burned smell. Cracking it open for inspection was a good time to convert the power supply to run on 120 V, too.

After some power supply repair, it was time to power the machine up. The results were not half bad. It started up with a cryptic error message: “This is not a language.” Better than a dead screen. The keyboard wasn’t totally working, though. A bit of internet searching found that the error happens when the battery dies and the machine loses its configuration.

More walkthroughs will take a bit more work on the keyboard. But we were impressed it came up as far as it did, and we look forward to a future installment where the machine fully starts up.

[Adrian] mentioned the co-processor slot accepting a Raspberry Pi, something we’ve talked about before. Or, add an FPGA and make the plucky computer think it is a PDP/11.

Continue reading “BBC Master 128 Revealed” →

Restoring Dot Matrix Printer Cartridges For 2023

May 27, 2023 by 9 Comments

The noise of a dot matrix printer is probably as synonymous with 1980s computing as the modem handshake would become with the desktop experience a decade or more later. But unlike the computers that would have driven it, a dot matrix printer can still be a very useful device here in 2023. And why not? They’re cheap to operate and can produce surprisingly good quality when paired with suitable drivers. There is a snag though; while cartridges for popular models can still be found, there are plenty whose consumables are long gone. [Drygol] had an Apple ImageWriter II with exactly that problem, and after finding all his cartridges were non-functional, took a look at how to bring them back.

Inside a dot matrix cartridge is a fabric ribbon similar to the one that might once have been found on a typewriter. It’s not on a roll but folded into the space, and it’s drawn through by a pair of rollers. Not only had the ink on the fabric dried out, but the foam on the rollers had also disintegrated. Some careful dismantling, and a solution presented itself in the form of O-rings to replace the rollers. Those and a bit of mineral oil to soften the ink had the vintage Apple printing again as though it was the ’80s once more.

It’s a subject we’ve looked at before, as it turns out WD-40 makes a good ink solvent.

When The Professionals Trash Your Data Tape, Can It Still Be Recovered?

May 26, 2023 by 17 Comments

People trying to preserve digital artifacts held on old media often not only have to contend with the media themselves decaying, but also with obscure media formats for which there’s seemingly little chance of finding a working reader. [Kneesnap] had this problem with a tape containing the only known copy of all the assets for the game Frogger 2: Swampy’s Revenge, and the tale of how the data was recovered is a dive into both the shady side of the data recovery industry and some clever old-format hacking.

The tape was an Onstream cartridge, a short-lived format from a company whose first product hit the market at the end of the ’90s and who went bust in 2004. An old drive was found, but it proved to have a pinch roller melted with age, so in desperation the tape was sent to a data recovery company.

We admire the forbearance in not naming and shaming the data recovery company, because far from recovering the data they sent it back with the tape damaged and spliced — something you can do with an analogue tape but not a digital one without compromising the data. Then faced with an unrecoverable tape and a slightly different Onstream cartridge, how could anything be salvaged?

The answer came in overriding the drive’s sensors and initializing it with a known-good tape, then swapping out the tapes so that the drive, unaware anything had changed, could read whatever data it could find. In the event the vast majority of the archive was retrieved, making it a win for the preservation of that game.

This may be more involved than some recovery stories, but it’s not the first we’ve covered.

New Zealand’s First Microcomputer May Be This 1802

May 24, 2023 by 12 Comments

Hardware hackers of a certain age likely got started with microcontrollers via the RCA 1802 — a relatively easy-to-use processor that was the subject of several excellent articles in Popular Electronics magazine back in the late 1970s. [Al’s Geek Lab] has an interview with [Hugh Anderson], who saw the articles and eventually designed the HUG1802, which may be the first microcontroller kit designed and sold in New Zealand.

The 1802 was very attractive at the time since it was inexpensive, static, didn’t require exotic voltages, and had a DMA system that allowed you to load software without complex ROMs. He initially marketed a kit unsuccessfully until an Australian company convinced him to create a proper PC board — the resulting kit was sold to about 100 customers.

The HUG1802 reminded us somewhat of the Quest Super Elf since it had a keypad, a cassette interface, and even a TV output. The 1802 had a DMA-enabled chip that made crude memory-mapped video output. The computer eventually morphed into the ETI 660, which they talk about at the end of the interview.

A lot of people built 1802 computers back in those days. If you don’t have an 1802, but you have an Arduino… ell, there’s always emulation.

Continue reading “New Zealand’s First Microcomputer May Be This 1802” →

Commodore 64 Upgrade In Modern Package

May 23, 2023 by 46 Comments

While the Commodore 64 was an immensely popular computer for its time, and still remains a strong favorite within the retrocomputing community, there’s a reason we’re not using modern Commodore-branded computers today. Intense competition, company mismanagement, and advancing beyond 8-bit computers too late in the game all led to the company’s eventual downfall. But if you’re still a Commodore enthusiast and always wished you were able to get an upgraded C64, you might want to take a look at the Commander X16, a modern take on this classic computer.

We’ve actually seen the Commander X16 before, but this was back in its early days of prototyping and design. This video from [Adrian’s Digital Basement], also linked below the break, takes a look at how it’s come in the four years since [David Murray] started this project. At its core, it’s an 8-bit 6502-based computer like you’d find in the 1980s but built with new components. There are some more modern updates as well such as the ability to use an SD card as well as built-in SNES controller ports, but the real magic here is the VERA module. Built around an FPGA, this module handles graphics, some of the audio, and the storage capabilities and does all of these things much better than the original Commodore, while still being faithful to what made these computer great.

While the inclusion of the FPGA might offend some of the most staunch 8-bit purists, it turns out to be necessary due to the lack of off-the-shelf video chips and really makes this build shine in the end. It’s also capable of running 6502-based software from other machines too, including the original NES. The VERA module makes it possible to run other software too, including a sample of Sonic the Hedgehog from the Sega Genesis which [Adrian] demonstrates in his video. 6502-based computers are quite versatile as the Commander X16 demonstrates, and it’s even possible to build a rudimentary 6502 on a breadboard with just a few parts.

Continue reading “Commodore 64 Upgrade In Modern Package” →

A Look Back At Computer Displays

May 21, 2023 by 10 Comments

These days, our video cards are actually as powerful as yesterday’s supercomputer and our monitors are bigger than the TVs most of us had as kids. But how did we get there? [RetroBytes] covers computer displays starting with the Colossus computer to today.

Back in the days of Colossus, of course, a display was actually a TeleType-like device printing on a roll of paper. The Manchester Baby actually had a crude display which was actually a Williams tube (no relation) that used phosphor persistence to store data. You could physically see memory on the tube or monitor it on a parallel tube — an early form of memory-mapped display.

Continue reading “A Look Back At Computer Displays” →

Supercon 2022: Andy Geppert Is Bringing Core Memory Back

May 18, 2023 by 20 Comments

Many Hackaday readers will be familiar with the term “core memory”, likely thanks to its close association with the Apollo Guidance Computer. But knowing that the technology existed at one point and actually understanding how it worked is another thing entirely. It’s a bit like electronic equivalent to the butter churn — you’ve heard of it, you could probably even identify an image of one — but should somebody hand you one and ask you to operate it, the result probably won’t be too appetizing.

That’s where Andy Geppert comes in. He’s turned his own personal interest into magnetic core memory into a quest to introduce this fascinating technology to a whole new generation thanks to some modern enhancements through his Core64 project. By mating the antiquated storage technology with a modern microcontroller and LEDs, it’s transformed into an interactive visual experience. Against all odds, he’s managed to turned a technology that helped put boots on the Moon half a century ago into a gadget that fascinates both young and old.

In this talk at the 2022 Hackaday Supercon, Andy first talks the audience through the basics of magnetic core memory as it was originally implemented. From there, he explains the chain of events that lead to the development of the Core64 project, and talks a bit about where he hopes it can go in the future.

Continue reading “Supercon 2022: Andy Geppert Is Bringing Core Memory Back” →