Ask Hackaday: Why Retrocomputing?

August 16, 2023 by Al Williams 81 Comments

I recently dropped in on one of the Vintage Computer Festival events, and it made me think about why people — including myself — are fascinated with old computer technology. In my case, I lived through a lot of it, and many of the people milling around at VCF did too, so it could just be nostalgia. But there were also young people there.

Out of curiosity, I asked people about the appeal of the old computers on display there. Overwhelmingly, the answer was: you can understand the whole system readily. Imagine how long it would take you to learn all the hardware and software details of your current desktop computer CPU. Then add your GPU, the mass storage controllers, and your network interface. I don’t mean knowing the part numbers, specs, and other trivialities. I mean being able to program, repair, and even enhance it.

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VCF East 2023: Alan Wolke On His Passion For Tech

May 8, 2023 by Tom Nardi 3 Comments

If you’re one of the more than 180,000 subscribers to [Alan Wolke]’s YouTube channel W2AEW, you’ll know he’s a lover of old test gear and ham radio hardware. You may have followed one of his tutorials, or referenced his work while repairing or upgrading your own equipment. But when we got a chance to talk to him one-on-one during Vintage Computer Festival East 2023, we were treated to a more personal look at the man himself.

Like many of us, [Alan] says he got his start with electronics at a young age simply by taking things apart and trying to put them back together again. From there he got a job in a TV repair shop during high school, where he was able to hone his natural curiosity into a marketable skill. His career took him through several of tech companies, but he ultimately ended up in an engineering role at Tektronix, a position he’s held for nearly 20 years.

Despite continuing to stay on the cutting edge, it’s no surprise that he still has a certain attraction to the technology from his youth. But it’s more than simple nostalgia — he points out that vintage hardware is generally easier to service than modern gear. As many of his own videos show, there was something of a technological “sweet spot” around the mid-20th century to the 1980s or so; where you could expect to not only have schematics available, but the design and construction of hardware was such that you could still reason your way through it using basic troubleshooting principles.

As for being a ham, [Alan] thinks it’s a great way for get an even deeper understanding of technology. He says that if you’re interested in learning how electronics work, repairing and upgrading old radio hardware is a great way to flex your mental muscles. But at the same time, being a ham isn’t limited to dusting off war-surplus radios that were built before you were born. There’s plenty of ways to mix in modern technology, from digital modes to receiving signals from satellites using a software-defined radio.

[Alan] was just one of the fascinating people we got a chance to speak with during our visit to the 2023 Vintage Computer Festival East. We’ve still got more interviews to come, but in the meantime, you can check out our previous coverage of this incredible retrocomputing event.

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HP-200LX Runs Website Like It’s The 90s

May 21, 2022 by Donald Papp 20 Comments

The HP-200LX palmtop was a fascinating machine for its time, and [Terrence Vergauwen] proves that its time is not yet over, given that one is responsible for serving up the website for Palmtop Tube, a website and YouTube channel dedicated to vintage palmtops.

All by itself a HP-200LX doesn’t have quite what it takes to act as a modern web server, but it doesn’t take much to provide the missing pieces. A PCMCIA network adapter provides an Ethernet connection, and a NAS contains the website content while networking and web server software run locally. Steady power comes from a wall adapter, but two rechargeable AA cells in the 200LX itself act as a mini-UPS, providing backup power in case of outages.

The HP-200LX was a breakthrough product that came just at the right time, preceding other true palm top computers like the IBM PC 110. In the early 90s, it was unimaginable that one could have a fully functional MS-DOS based machine in one’s pocket, let alone one that could last weeks on a couple of AA cells. It didn’t have some proprietary OS and weird ports, and that kind of functionality is part of why, roughly 30 years later, one is able to competently serve up web traffic.

A video overview of the machine and how it all works is in the video embedded below. And if you’re more interested in what an HP-200LX looks like on the inside? This video is all about taking apart and repairing a 200LX.

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Web Emulator For The Kenbak-1 Computer (If You’ve Heard Of It)

May 7, 2022 by Donald Papp 16 Comments

Ever heard of the KENBAK-1? Recognized as the first personal computer, created by John Blankenbaker and sold in 1971 in comparatively small numbers, it’s now a piece of history. But don’t let that stop you if you are curious, because of course there is an emulator on the web.

If the machine looks a bit strange, that’s because early computers of this type did not have the kind of controls (or displays) most people would recognize today. Inputs were buttons and switches, and outputs were lights showing binary values of register contents. The machine could store and run programs, and those programs were entered in pure machine code (no compiler, in other words) by setting individual bit values via the switches. In fact, the KENBAK-1’s invention preceded that of the microprocessor.

The KENBAK was the first electronic, commercially available computer that was not a kit and available to the general population, but the story of how it came to be is interesting. Back in 2016 we covered how that story was shared by John Blankenbaker himself at Vintage Computer Festival East.

Paper Tape Reader Self-calibrates, Speaks USB

April 16, 2022 by Donald Papp 20 Comments

Input devices consisting of optical readers for punched paper tape have been around since the earliest days of computing, so why stop now? [Jürgen]’s Paper Tape Reader project connects to any modern computer over USB, acting like a serial communications device. Thanks to the device’s automatic calibration, it works with a variety of paper materials. As for reading speed, it’s pretty much only limited to how fast one can pull tape through without damaging it.

Stacked 1.6 mm PCBs act as an enclosure, of sorts.

While [Jürgen]’s device uses LEDs and phototransistors to detect the presence or absence of punched holes, it doesn’t rely on hardware calibration. Instead, the device takes analog readings of each phototransistor, and uses software-adjusted thresholds to differentiate ones from zeros. This allows it to easily deal with a wide variety of tape types and colors, even working with translucent materials. Reading 500 characters per second isn’t a problem if the device has had a chance to calibrate.

Interested in making your own? The build section of the project has all the design files; it uses only through-hole components, and since the device is constructed from a stack of 1.6 mm thick PCBs, there’s no separate enclosure needed.

Paper tape and readers have a certain charm to them. Cyphercon 4.0 badges featured tape readers, and we’ve even seen the unusual approach of encoding an I²C byte stream directly onto tape.

A vintage supercomputer with unique dual screen display

VCF East 2021: The Early Evolution Of Personal Computer Graphics

October 29, 2021 by Chris Wilkinson 12 Comments

The evolution of computer graphics is something that has been well documented over the years, and it’s a topic that we always enjoy revisiting with our retrocomputing readers. To wit, [Stephen A. Edwards] has put together an impressively detailed presentation that looks back at the computer graphics technology of the 1960s and 70s.

The video, which was presented during VCF East 2021, goes to great lengths in demystifying some of the core concepts of early computer graphics. There’s a lot to unpack here, but naturally, this retrospective first introduces the cathode-ray tube (CRT) display as the ubiquitous technology that supported computer graphics during this time period and beyond. Building from this, the presentation goes on to demonstrate the graphics capabilities of DEC’s PDP-1 minicomputer, and how its striking and surprisingly capable CRT display was the perfect choice for playing Spacewar!

As is made clear in the presentation, the 1960s featured some truly bizarre concepts in regards to cutting edge computer graphics, such as Control Data Corporation’s 6600 mainframe and accompanying vector-based dual-CRT video terminal, which wouldn’t look out of place on the Death Star. Equally strange at the time was IBM’s 2260 video data terminal, which used a ‘sonic delay line’ as a type of rudimentary video memory, using nothing but coiled wire, transducers and sound itself to store character information following a screen refresh.

These types of hacks were later replaced by solid state counterparts during the microcomputer era. The video concludes with a look back at the ‘1977 trinity’ of microcomputers, namely the Apple II, Commodore PET and TRS-80. Each of these microcomputers handled graphics in a slightly different way, and it’s in stark contrast to today’s largely homogenised computer graphics landscape.

There’s a lot more to this great retrospective, so make sure to check out the video below. When you’re finished watching, make sure to check out our other coverage of VCF 2021, including some great examples of computer preservation and TTL-based retrocomputing.

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A composite of a disassembled and reassembled Model F keyboard

Model F Keyboard Restoration Goes The Extra Mile

October 8, 2021 by Chris Wilkinson 19 Comments

The IBM Model F keyboard should need no introduction. Famed for its buckling spring key mechanisms, the Model F is lusted over for its satisfying typing experience and Armageddon-proof build quality. First introduced in 1981, many of these keyboards will now naturally require basic maintenance. However, [Epictronics] recently went a step further and restored a Model F to like-new condition.

Missing keycaps were the least of his worries, as both new and old replacements are relatively easy to come by. [Epictronics] was more concerned about the forty-year-old foam sandwiched tight inside the keyboard, most likely having long since degraded. Apart from being plain gross, the decaying foam has the potential to foul the buckling spring switches. After taking apart the body and removing the ‘disgusting’ foam pad, a replacement was forged from neoprene and a handy-dandy hole punch.

Disassembly of the keyboard case required the gentle touch of a mallet, and reassembly needed similarly inappropriate tools. As demonstrated in this vintage clip from IBM, keyboard assembly was (and still is) performed automatically by robots, driven by an IBM Series/1 minicomputer. These robots were equally impressive for their precision and strength. Without access to IBM’s aptly named ‘closing tool’ and various other robotic helpers, [Epictronics] had to settle for pool noodles and a comically large clamp during reassembly, mixed with sheer determination.

Other neat tricks in the video include applying heat to reform the coiled keyboard cable, and using car polish to clean the case plastics. The latter has the potential to make things worse, so a delicate hand is needed to maintain the textured plastic.

We recently covered another Model F restoration, and it’s exciting to see so many dedicated hackers keeping these keyboards clickety-clacking well into the 21st century.

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