Programming An Oscilloscope Breakout Game In Pure Data

[S-ol] wrote in to share his sweet breakout game played on an oscilloscope. Built in a weekend as part of a game development jam, Plonat Atek is a polar breakout game where the player attacks the center and the ball bounces around the perimeter. You can play it either on an oscilloscope or using an online emulator. [S-ol] wrote the game in Pure Data, a visual programming language for audio. The software controls the audio out channels and uses sound to control the game graphics. He also made use of the Zexy extension for Pure Data.

One of the cool things about this setup is that since the game is programmed with sound, all the sound effects also double as visual effects

We love oscilloscopes, and not just because they’re useful as hell. They also make sweet vector displays, like this analog pong game that uses a scope for a display. Even when they’re not being used for retrogaming they can be capable of some pretty amazing graphics.

Homemade LED Clock Stands Test Of Time

In an era when you might get chastised if your mobile phone is more than two years old, it’s easy to forget that hardware was not always meant to be a temporary commodity. We acknowledge a few standout examples of classic hardware still surviving into the modern era, such as vintage computers, but they’re usually considered to be more of a novelty than an engineering goal. In a disposable society, many have forgotten that quality components and a well thought out design should give you a service life measured in decades, not months.

A perfect example of this principle is the beautiful LED clock built 40 years ago by [Davide Andrea]. A teenager at the time, [Davide] built this clock to be used by the local radio station, as clocks that showed seconds were important for timing radio shows. Finding it in storage recently, [Davide] took to the /r/electronics subreddit to report that it still works fine after all these years.

Cracking open the case shows a unique and highly functional construction style. Notches cut into the side panels of the case accept individual protoboards in a “blade” type configuration, with the blades connected by a handful of individual wires. No digging through the parts bin for a “worthless” old IDE cable to tear up back in the 1970’s.

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3D Printing Belts For Vintage Hardware

It may be hard for some of the younger readers to believe, but there was a time when hardware was full of little rubber belts. Tape decks, VCRs, even some computers: they all had rotating parts that needed to transfer power to other components, and belts were a cheap and quiet way to do it. Unfortunately, now decades later we realize that these little belts are often the Achilles heel of classic hardware, getting brittle and breaking long before the rest of the components are ready to give up the fight.

Which is exactly what [FozzTexx] found when trying to revive his newly purchased Commodore PET 2001. The belt inside of the cassette drive had become hard and fallen to pieces, and rather than hunt around for a replacement, [FozzTexx] reasoned he might be able to print one out of a flexible 3D printer filament like NinjaFlex. Besides, this wasn’t the only piece of vintage tech in his house that needed a belt replacement, so he figured it would be a worthwhile experiment.

As the original belt was little more than dust, [FozzTexx] had to design his replacement from scratch. He started by cleverly replicating the path the belt would need to take with string, and then measuring the inside diameter of the string circle with his calipers. [FozzTexx] then reduced the diameter by 5% to take into account the stretching of the new belt.

The profile of the belt was square, which made modeling and 3D printing much easier. [FozzTexx] just subtracted a smaller circle from a larger one in 2D, and then extruded that circle into the third dimension by 1.18 mm to match the height of the original part. Careful measurement paid off, and the newly printed NinjaFlex belt had his Commodore loading and saving programs on the first try.

We’ve covered the difficulty in sourcing replacement belts for old hardware previously, so it will be interesting to see if others are able to make use of the research [FozzTexx] has done here. Of course, longevity concerns are always brought up when NinjaFlex is used, so hopefully [FozzTexx] keeps us updated.

Yellowing: The Plastic Equivalent Of A Sunburn

Your fancy white electronic brick of consumer electronics started off white, but after some time it yellowed and became brittle. This shouldn’t have happened; plastic is supposed to last forever. It turns out that plastic enclosures are vulnerable to the same things as skin, and the effects are similar. When they are stared at by the sun, the damage is done even though it might not be visible to you for quite some time.

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ESP8266 As A Tape Drive

1976 was the year the Apple I was released, one of several computers based on the MOS 6502 chip. MOS itself released the KIM-1 (Keyboard Input Monitor) initially to demonstrate the power of the chip. The single board computer had two connectors on it, one of which could be used for a tape recorder for long-term storage. When [Willem Aandewiel] went to the Apple Museum Nederland in 2016, he saw one and felt nostalgic for his youth. He was able to get a replica, the microKIM, and build it but he wanted to use new technology to interface with this old technology, so he decided to use an ESP8266 as a solid state tape recorder.

One of the reasons the KIM-1 was so popular when it was released was that there was lots of documentation available. [Willem] used this documentation to figure out how the KIM-1 saves data to the recording device. An ATTiny85 is used to decode the pulse stream that the KIM-1 sends when saving because the timing was too tight to both “listen” and decode the bits as well as convert and store them. For loading programs, the data can be sent digitally as 1’s and 0’s to the KIM-1. This means that the ATTiny is only used for decoding and doesn’t have to re-encode the data.  Because of this, saving is slow, but loading is very quick.

To complete the project, [Willem] added four buttons, one each for rewind, record, play and fast-forward, and a screen so you can see which program is currently selected and can go from one program to another. As a nice throwback touch, record and play have to be pressed at the same time when saving. For more 6502 projects, check out this 6502 based DIY computer, or this 6502 built from discrete parts.

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Finally – A Big-Screen Vectrex

The Vectrex is in no way the most popular console of all time, but it is one of the more unique. Eschewing typical raster-based rendering, it instead relies on a vector-based display. Since the average home television of the era would be completely unable to display such signals, the Vectrex had its screen built in. This got [Arcade Jason] wondering – would it be possible to hook the Vectrex up to a bigger screen?

First, a suitable monitor had to be found. The 19V2000 turned out to be a good candidate – much larger at 19 inches, and found in a variety of arcade cabinets from years past. From there, the project became a matter of identifying the signal outputs of the Vectrex. [Arcade Jason] took the liberty of modifying the levels of the signals on the Vectrex board itself, and then fixing the now-overscanned image on the original screen by adjusting the onboard trimpots. With the Vectrex’s X and Y signals now boosted somewhat, they were wired up to the inputs of the larger arcade screen. For the Z signal, things got even hackier – a Walmart “Computer Amplifier”, typically used for speakers, was instead pressed in to service to amplify the signal.

There are plenty of wires running all over the carpet in this video, but the fact is, it works brilliantly. Future plans involve upgrading to an even larger 23 inch monitor, and possibly even experiments with color vector displays. It just goes to show that the Vectrex, even today, maintains a die-hard following.

Perhaps you’d like to try this, but need to fix your original Vectrex screen first? Never fear – that’s possible, too.

 

Teardown With A Twist: 1975 Sinclair Scientific Calculator

When writing a recent piece about Reverse Polish Notation, or RPN, as a hook for my writing I retrieved my Sinclair Scientific calculator from storage. This was an important model in the genesis of the scientific calculator, not for being either a trailblazer or even for being especially good, but for the interesting manner of its operation and that it was one of the first scientific calculators at an affordable price.

I bought the calculator in a 1980s rummage sale, bodged its broken battery clip to bring it to life, and had it on my bench for a few years. Even in the early 1990s (and even if you didn’t use it), having a retro calculator on your bench gave you a bit of street cred. But then as life moved around me it went into that storage box, and until the RPN article that’s where it stayed. Finding it was a significant task, to locate something about the size of a candy bar in the storage box it had inhabited for two decades, among a slightly chaotic brace of shelves full of similar boxes.

The Sinclair's clean design still looks good four decades later.
The Sinclair’s clean design still looks good four decades later.

Looking at it though as an adult, it becomes obvious that this is an interesting machine in its own right, and one that deserves a closer examination. What follows will not be the only teardown of a Sinclair Scientific on the web, after all nobody could match [Ken Shirriff]’s examination of the internals of its chip, but it should provide an insight into the calculator’s construction, and plenty of satisfying pictures for lovers of 1970s consumer electronics.

The Sinclair is protected by a rigid black plastic case, meaning that it has survived the decades well. On the inside of the case is a crib sheet for its RPN syntax and scientific functions, an invaluable aid when it comes to performing any calculations.

It shares the same external design as the earlier Sinclair Cambridge, a more humble arithmetic calculator, but where the Cambridge’s plastic is black, on the Scientific it is white. The LED display sits behind a purple-tinted window, and the blue-and-black keyboard occupies the lower two-thirds of the front panel. At 50 x 111 x 16 mm it is a true pocket calculator, with an elegance many of its contemporaries failed to achieve and which is certainly not matched by most recent calculators. Good industrial design does not age, and while the Sinclair’s design makes it visibly a product of the early 1970s space-age aesthetic it is nevertheless an attractive item in its own right.

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