Retro Calculator Build Proves The Space Age Isn’t What It Used To Be

November 14, 2024 by Dan Maloney 19 Comments

The common wisdom these days is that even if we wanted to get back to the Moon the way we did in the 1960s, we’d never be able to do it. Most of the blame for that usually falls on the loss of institutional knowledge thanks to skilled minds and hands that have been stilled by the passage of time, but the real kicker would be finding replacements for all the parts that we used back then that just aren’t made anymore. A similar problem exists for those seeking to recreate the circuits that graced the pages of the many magazines that catered to electronics hobbyists back in the day.

Take this “Space Age Decimal Computer” reproduction that [Bob Alexander] undertook. Smitten with the circuit after seeing our story about a 1966 article detailing its construction, he decided to roll one of his own. That proved to be far harder than he thought it would be. The original circuit, really little more than an adding machine using a rotary telephone dial as an input device, used neon lamp ring buffers for counting, The trouble is, while NE-2 neon lamps are still made, they aren’t made very precisely. That makes it difficult to build a working ring buffer, which relies on precise on and off voltages. That was even a problem back then; the author suggested buying 100 lamps and carefully characterizing them after aging them in to get the 60 lamps needed.

In the end, [Bob] settled for modifying the circuit while making the build look as close as possible to the original. He managed to track down the exact model of enclosure used in the original. The front panel is populated with a rotary dial just like the original, and the same neon lamps are used too, but as indicators rather than in ring buffers. Behind the scenes, [Bob] relied on 7400-series counters and decoders to make it all work — kudos for sticking with 1970s tech and not taking the easy way out with an Arduino.

The video below goes into more detail on the build and the somewhat kludgy operation of the machine, with a few excellent [Tom Lehrer] references and a nice Cybertruck dunk to boot.

Continue reading “Retro Calculator Build Proves The Space Age Isn’t What It Used To Be” →

The Most Inexpensive Apple Computer Possible

November 7, 2024 by Bryan Cockfield 20 Comments

If Apple has a reputation for anything other than decent hardware and excellent industrial design, it’s for selling its products at extremely inflated prices. But there are some alternatives if you want the Apple experience on the cheap. Buying their hardware a few years out of date of course is one way to avoid the bulk of the depreciation, but at the extreme end is this working Mac clone that cost just $14.

This build relies on the fact that modern microcontrollers absolutely blow away the computing power available to the average consumer in the 1980s. To emulate the Macintosh 128K, this build uses nothing more powerful than a Raspberry Pi Pico. There’s a little bit more to it than that, though, since this build also replicates the feel of the screen of the era as well. Using a “hat” for the Pi Pico from [Ron’s Computer Videos] lets the Pico’s remaining system resources send the video signal from the emulated Mac out over VGA, meaning that monitors from the late 80s and on can be used with ease. There’s an option for micro SD card storage as well, allowing the retro Mac to have an incredible amount of storage compared to the original.

The emulation of the 80s-era Mac is available on a separate GitHub page for anyone wanting to take a look at that. A VGA monitor is not strictly required, but we do feel that displaying retro computer graphics on 4K OLEDs leaves a little something out of the experience of older machines like this, even if they are emulated. Although this Macintosh replica with a modern e-ink display does an excellent job of recreating the original monochrome displays of early Macs as well.

Continue reading “The Most Inexpensive Apple Computer Possible” →

Are CRT TVs Important For Retro Gaming?

October 11, 2024 by Dave Rowntree 50 Comments

We always thought the older console games looked way better back in the day on old CRTs than now on a modern digital display. [Stephen Walters] thinks so too, and goes into extensive detail in a lengthy YouTube video about the pros and cons of CRT vs digital, which was totally worth an hour of our time. But are CRTs necessary for retro gaming?

The story starts with [Stephen] trying to score a decent CRT from the usual avenue and failing to find anything worth looking at. The first taste of a CRT display came for free. Left looking lonely at the roadside, [Stephen] spotted it whilst driving home. This was a tiny 13″ Sanyo DS13320, which, when tested, looked disappointing, with a blurry image and missing edges. Later, they acquired a few more displays: a Pansonic PV-C2060, an Emerson EWF2004A and a splendid-looking Sony KV24FS120. Some were inadequate in various ways, lacking stereo sound and component input options.

A poor analog cable coupled with rendering inaccuracy gives a nice filtering effect

A large video section discusses the reasons for the early TV standards. US displays (and many others using NTSC) were designed for 525 scan lines, of which 480 were generally visible. These displays were interlaced, drawing alternating fields of odd and even line numbers, and early TV programs and NTSC DVDs were formatted in this fashion. Early gaming consoles such as the NES and SNES, however, were intended for 240p (‘p’ for progressive) content, which means they do not interlace and send out a blank line every other scan line. [Stephen] goes into extensive detail about how 240p content was never intended to be viewed on a modern, sharp display but was intended to be filtered by the analogue nature of the CRT, or at least its less-than-ideal connectivity. Specific titles even used dithering to create the illusion of smooth gradients, which honestly look terrible on a pixel-sharp digital display. We know the differences in signal bandwidth and distortion of the various analog connection standards affect the visuals. Though RGB and component video may be the top two standards for quality, games were likely intended to be viewed via the cheaper and more common composite cable route.

Continue reading “Are CRT TVs Important For Retro Gaming?” →

Curing CRT Cataracts Freshens Up Retro Roundy TVs

September 29, 2024 by Dan Maloney 12 Comments

It’s been a long time since the family TV has had a CRT in it, and even longer since that it was using what was basically an overgrown oscilloscope tube. But “roundies” were once a thing, and even back in the early 80s you’d still find them in living rooms on TV repair calls, usually sporting a characteristic and unsightly bullseye discoloration.

Fast-forward a few decades, and roundy TVs have become collectible enough that curing their CRT cataracts is necessary for restorationists like [shango066], a skill he demonstrates in the video below. The defect comes from the composite construction of CRTs — a safety feature added by television manufacturers wisely concerned with the safety aspects of putting a particle accelerator with the twin hazards of high vacuum and high voltage in the family home. The phosphor-covered face of the tube was covered by a secondary glass cover, often tinted and frosted to improve the admittedly marginal viewing experience. This cover was often glued in place with an epoxy resin that eventually oxidized from the edges in, making the bullseye pattern.

The remedy for this problem? According to [shango066], it’s heat, and plenty of it. After liberating the tube from the remarkably clean TV chassis, he took advantage of a warm summer’s day and got the tube face cooking under a black plastic wrap. Once things were warmed up, more heat was added to really soften the glue; you can easily see the softening progress across the face of the tube in the video below. Once softened, gentle prying with wooden chopsticks completes the job of freeing the safety lens, also in remarkably good shape.

With the adhesive peeled off in an oddly satisfying manner, all that’s left is a thorough cleaning and gluing the lens back on with a little silicone sealant around the edges. We’d love to see the restored TV in operation, but that’s left to a promised future video. In the meantime, please enjoy a look at the retro necessities TV owners depended on in the good old days, which really weren’t all that good when you get down to it.

Continue reading “Curing CRT Cataracts Freshens Up Retro Roundy TVs” →

Taking Back The Internet With The Tildeverse

September 14, 2024 by Dave Rowntree 25 Comments

For many of us of a particular vintage, the internet blossomed in the ’90s with the invention of the Web and just a few years of development. Back then, we had the convenience of expression on the WWW and the backup of mature services such as IRC for all that other stuff we used to get up to. Some of us still hang out there. Then something happened. Something terrible. Big-commerce took over, and it ballooned into this enormously complex mess with people tracking you every few seconds and constantly trying to bombard you with marketing messages. Enough now. Many people have had enough and have come together to create the Tildeverse, a minimalist community-driven internet experience.

A collaborative Minecraft server hosted on a Tilde site

Tilde, literally ‘ ~ ‘, is your home on the internet. You can work on your ideas on a shared server or run your own. Tilde emphasises the retro aesthetic by being minimal and text-orientated. Those unfamiliar with a command line may start getting uncomfortable, but don’t worry—help is at hand. The number of activities is too many to list, but there are a few projects, such as a collaborative Sci-Fi story, a radio station, and even a private VoIP server. Gamers are catered for as long as you like Minecraft, but we think that’s how it should go.

The Tildeverse also supports Gopher and the new Gemini protocol, giving some people a few more options with which to tinker. The usual method to gain access is to first sign up on a server, then SSH into it; you’re then taken to your little piece of the internet, ready to start your minimalist journey into the Tildeverse.

A couple of videos after the break go into much more detail about the whys and hows of the Tildeverse and are worth a chunk of your time.

We’ve talked about the ‘small web’ before. Here’s our guide to Gemini.

Continue reading “Taking Back The Internet With The Tildeverse” →

A black device with a monochrome LCD sits on a wooden table. It's keyboard extends below the frame. On the screen is the "Level 29" BBS service login.

Internet Appliance To Portable Terminal

August 8, 2024 by Navarre Bartz 2 Comments

Few processors have found themselves in so many different devices as the venerable Z80. While it isn’t powerful by modern standards, you can still use devices like this Cidco MailStation as a terminal.

The MailStation was originally designed as an email machine for people who weren’t onboard with this whole computer fad, keeping things simple with just an adjustable monchrome LCD, a keyboard, and a few basic applications. [Joshua Stein] developed a terminal application, msTERM, for the MailStation thanks to work previously done on decoding this device and the wealth of documentation for Z80 assembly.

While [Stein] designed his program to access BBSes, we wonder if it might be a good way to do some distraction-free writing. If that wasn’t enough, he also designed the WiFiStation dongle which lets you communicate over a network without all that tedious mucking about with parallel ports.

If you’d like something designed specifically for writing, how about an AlphaSmart? Wanting to build your own Z80-based project? Why not start with an Altoids-sized Z80 SBC, but don’t wait forever since Z80 production finally ended in June.

Continue reading “Internet Appliance To Portable Terminal” →

A System Board For The 8008

May 27, 2024 by Bryan Cockfield 27 Comments

Intel processors, at least for PCs, are ubiquitous and have been for decades. Even beyond the chips specifically built by Intel, other companies have used their instruction set to build chips, including AMD and VIA, for nearly as long. They’re so common the shorthand “x86” is used for most of these processors, after Intel’s convention of naming their processors with an “-86” suffix since the 1970s. Not all of their processors share this convention, though, but you’ll have to go even further back in time to find one. [Mark] has brought one into the modern age and is showing off his system board for this 8008 processor.

The 8008 predates any x86 processor by about six years and was among the first mass-produced 8-bit processors even before the well-known 8080. The expansion from four bits to eight was massive for the time and allowed a much wider range of applications for embedded systems and early personal computers. [Mark] goes into some of the details for programming these antique processors before demonstrating his system board. It gets power from a USB-C connection and uses a set of regulators and level shifters to make sure the voltages all match. Support for all the functions the 8008 needs is courtesy of an STM32. That includes the system memory.

For those looking to develop something like this, [Mark] has also added his development tools to a separate GitHub page. Although it’s always a good idea for those interested in computer science to take a look at old processors like these, it’s not always the easiest path to get original hardware like this, which also carries the risk of letting smoke out of delicate components. A much easier route is to spin up an emulator like an 8086 IBM PC emulator on an ESP32. Want to see inside this old chip? Have a look.

Continue reading “A System Board For The 8008” →