Windows 98 For Spaceships? Not Quite!

July 6, 2022 by Jenny List 78 Comments

One of the news items that generated the most chatter among Hackaday editors this week was that ESA’s Mars Express mission is receiving a software update. And they’re updating the operating system to…Windows 98.

Microsoft’s late-90s consumer desktop operating system wouldn’t have been the first to come to mind as appropriate for a spacecraft, but ESA were quick to remind us that it was the development toolchain, not the craft itself, that depended upon it. It’s still quite a surprise to find Windows 98 being dusted off for such an unexpected purpose, and it’s led us to consider those now-almost-forgotten operating systems once more, and to question where else it might still be found. Continue reading “Windows 98 For Spaceships? Not Quite!” →

A 3D-printed device labelled "BlixTerm" plugged into the back of a Commodore PET

BlixTerm Brings Full-Speed YouTube Video To The Commodore PET

July 1, 2022 by Robin Kearey 13 Comments

If you’ve ever used a home computer from the late 1970s or early 1980s, you’ll no doubt be familiar with the slow speed of their user interfaces. Even listing the contents of a BASIC program from RAM could take several seconds, with the screen updating one line at a time. Video games were completely optimized for speed, but could still handle just a few slowly-moving objects at the same time. Clearly, playing anything resembling full-motion video on hardware from that era would be absolutely impossible – or so you might think.

In fact, [Thorbjörn Jemander] has managed to persuade a Commodore PET to play YouTube videos at a completely reasonable 30 frames per second. He describes the process of designing the “BlixTerm” hardware and software in his video (embedded below), along with lots of useful information on how to push digital systems to their absolute limits.

Naturally, the PET needs a bit of assistance from modern hardware, in this case a Raspberry Pi Zero 2 W hooked up to the “User” expansion port. The Pi connects to YouTube through WiFi and loads the requested video, then downconverts it to a 640×200 grayscale stream and transforms each frame to an 80×25 grid of characters, using those from the PET’s ROM that most closely resemble the pattern needed.

While it took quite some effort to squeeze enough performance out of the Pi to do all of this in real time, the trickiest bit was getting the resulting character stream into the PET’s video memory fast enough. To do this, [Thorbjörn] designed a special interface card with 2 KB of dual-port SRAM, which enabled the Pi to store its video frames as soon as they were ready on one side, and the PET to load them at its own pace from the other side. With just sixteen microseconds available to process each byte, the PET’s CPU can execute only four or five machine code instructions; barely enough to load and store a single character and jump to the next memory address.

The end result, as you can see in the video, is really impressive. Even within the constraints of the Commodore character set, the resulting image is clearly recognizable, while the frame rate seems to defy the hardware’s limitations.

If you’re a Commodore aficionado and wondering what the hell that weird PET 600 model is all about, [Thorbjörn] made a video about that too; it’s a rebadged 8296 aimed at the Swedish market. We’ve actually seen a project to generate live video on the PET before, although at a much lower frame rate. Thanks for the tip, [Keith Olson]!

Continue reading “BlixTerm Brings Full-Speed YouTube Video To The Commodore PET” →

Hackaday Prize 2022: The Baffatari 2600 Adds Atari Compatibility To Retrocomputers

June 29, 2022 by Robin Kearey 16 Comments

Like today’s Intel-AMD duopoly, the market for home computer CPUs in the 1970s and ’80s was dominated by two players: Zilog with their Z80, and MOS Technology with their 6502 processor. But unlike today, even if two computers had the same CPU, it didn’t mean the two were software compatible: differences in memory layout, video interfaces, and storage media meant that software developed for an Atari 2600 wouldn’t run on an Apple I, despite the two sharing the same basic CPU architecture.

[Augusto Baffa]’s latest modern retrocomputer design, the Baffatari 2600, cleverly demonstrates that the difference between those two computers really is only skin-deep. The Baffatari is a plug-in board that adds Atari 2600 functionality to [Augusto]’s earlier Baffa-6502 system, which was designed to be Apple I-compatible. Since both the Apple and the Atari are powered by 6502 CPUs, only a few peripherals need to be swapped to change one into the other.

Sitting on the Baffatari board are two chips essential to the Atari 2600’s architecture: the 6532 RAM I/O Timer (RIOT) that contains the RAM and joystick interface, and the Television Interface Adapter (TIA) that handles the graphics and audio. These chips connect to the Baffa-6502’s system bus, enabling the main CPU to communicate with them and run Atari 2600 software titles. In the video embedded below, you can see several classic games running on the Baffa system.

The basic idea is similar to this RC2014 plug-in board that enables a Z80-based retrocomputer to run MSX and Colecovision titles. In fact, [Augusto] also built such a board for his earlier Z80 project.

Continue reading “Hackaday Prize 2022: The Baffatari 2600 Adds Atari Compatibility To Retrocomputers” →

Building A Serial Bus To Save An Old Hard Drive

June 28, 2022 by Bryan Cockfield 67 Comments

Universal Serial Bus has been the de facto standard for sending information to and from computer peripherals for almost two decades, but despite the word “universal” in the name this wasn’t always the case. Plenty of competing standards, including USB, existed in the computing world in the decades before it came to dominance, and if you’re trying to recover data from a computer without USB you might have to get creative with how it’s done.

[Ben] recently came across a 80486 with this problem, so he had to get creative to recover the contents of the drive. He calls it the “lunchbox” computer due to its form factor, and while it doesn’t have USB it does have a tried-and-trusted serial port to communicate with other computers. [Ben] wrote up a piece of software for both the receiving computer and the sending computer in order to copy the drive sectors one by one across a serial link to a standalone computer running Windows XP, and was able to recover the contents of the drive that way instead.

All of the code [Ben] wrote is available on his GitHub page for anyone looking to boot up a 30-year-old computer again. While it might sound uncommon, computers of this vintage are still around running things like CNC machines or old mainframes.

Retrocomputing, Time To Hang Up The Original Hardware?

June 28, 2022 by Jenny List 57 Comments

For those of us with penchant for older technology, there’s something special about operating with older hardware. Whether it’s a decades-old camera, a vintage keyboard, or a home computer from the 1980s, the modern equivalent just doesn’t quite compare. But working with older parts definitely isn’t for the faint-hearted, as the passage of time has taken its toll on their reliability. Is it time to recognize that the supply of replacement vintage parts is not infinite, and to switch from using original hardware to more modern alternatives? [Retro Recipes] poses this question after a particularly difficult-to-find Amiga fault, and discusses it while evaluating a replacement Amiga made entirely from modern parts.

The new Amiga in question is a recreation of an A1200 with a re-manufactured case and keyboard, and the guts of an A500 Mini retro console taking the place of the Commodore board. He goes through the process of making an Amiga hard drive image on a USB drive using the image from his original drive in his teenage years, and boots it both on the 500 Mini based machine and on the UAE emulator on a Mac laptop. You can follow him in the video below the break.

We can see the logic in treating original hardware as a precious resource that’s not to be run up for fear of breaking it, but by the same token we’re still standing by that first sentence. But should the enjoyment of an older machine be limited only to those who have an original? We think not, so if enjoying an Amiga without an Amiga can be as good as the real thing then we’re all for it.

Of course, for those whose original Amigas have already broken, there are other ways to bring them back.

Continue reading “Retrocomputing, Time To Hang Up The Original Hardware?” →

Atari At 50: The Story Of Our Lives

June 27, 2022 by Jenny List 14 Comments

It’s been a year of anniversaries, what with the 40th birthday of both the Commodore 64 and the Sinclair ZX Spectrum. But there’s another anniversary that in a sense tops them all, today marks 50 years since Nolan Bushnell and Ted Dabney incorporated Atari Inc, a name that will forever be synonymous with the development of the computer game industry. PC Magazine have marked the event with a retrospective, an affectionate look at the progress from Spacewar! coin-ops to the unsuccessful Jaguar console of the 1990s, and it pulls no punches over the lacklustre management that oversaw its decline in later years.

For us the high points of the Atari story were the VCS console and the ST line of computers, which probably best represent the brand’s successes in Europe where this is being written. It’s with something of a wince that we remember watching an Atari Lynx advert in a British cinema, in which the laugh came when the teenager-unaffordably high price was revealed. At least diehard Atari fans can take solace in that by then Commodore was equally being run into the ground.

One criticism PC Magazine makes is that the current Atari incarnation is doing little beyond rehashing past glories, and perhaps they’re right. Last year we covered their release of some new cartridges for the VCS.

Mysterious Adder From 1960s Bendix G-20

June 24, 2022 by Chris Lott 8 Comments

[David Lovett] aka Usagi Electric is taking a dive into yet another old computer design, this one from the early 1960s. He recently obtained eight mystery circuit boards on-loan for the purpose of reverse engineering them. It turns out these came from an old mainframe called the Bendix G-20, a successor to the 1965 G-15 vacuum tube model. The cards are:

Full Adder
AND Gate
OR Gate
Emitter Follower
Flip Flop
Quad Inverting Amplifier
DLO Amplifier
Gated CPA

Most of these are pretty straightforward to figure out, but he ran into some troubles trying to understand the full adder board. The first issue is there is some uncertainty surrounding the logic level voltages. This system uses negative voltages, with -3.5 V representing a logic 1 … or is it a logic 0? And even taking into account this ambiguity, [David] is having a hard time deciphering how the adder works. It uses a bunch of diodes to implement a logic lookup table of an adder — except he is not able to make it match any known addition scheme. [David] has called out to the community for help on this one, and if you have any ideas how this adder works, visit his wiki linked above for more information and give him shout.

We don’t know how [David] squeezes in the time for these side projects, when he is so busy on the Centurion mini-computer restoration and the monstrous single-bit vacuum tube computer he is building.

Continue reading “Mysterious Adder From 1960s Bendix G-20” →