Coin-Operated Graphing Calculator Console

Longtime hacker [Peter Jansen] was so impressed with a piece in The Onion from last year that he decided to build this coin-operated Texas Instruments graphing calculator console on a whim (video below the break — warning vertical orientation).

With nothing more to go on than the fake mock-up pictured from the original satirical article, [Peter] was able to scale the dimensions from the photo making a few reasonable assumptions. He built the project over the holidays, enlisting his father and daughter as helpers. The cabinet is framed in 2×3 lumber and faced with wood veneer covered plywood and vinyl overlays for the graphics.

The computing power is from a Raspberry Pi with an Arduino Uno serves as an I/O processor. It was a bit tricky to control a calculator with only two knobs, but he makes it work. However, at 25 cents per plot with no apparent hard-copy capability, this console calculator might be a bit pricey for all but casual plotting over a few beers at the local pub.

You might remember [Peter] from some of his hacks we featured over the years, like his home-brew CT scanner or placing fourth in the first Hackaday Prize contest in 2014 with the open sourced tricorder project.

 

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Teardown: Alcatel Telic 1 Minitel Terminal

For British teenagers in the 1980s, the delights of 8-bit computers such as the Sinclair Spectrum, Commodore 64, or BBC Micro were firmly restricted to the offline arena. We would read about the BBS scene on the other side of the Atlantic, but without cheap local calls and with a modem costing a small fortune, the chances of us ever experiencing one was zero. When we took the British school rite of passage of a trip to France though, we were astounded to see that every French person was not merely online, but that they were doing so with a neat little all-in-one terminal. We’d just been introduced to the French Minitel system, and in that minute shared a glimpse of the future.

Un Réseau Trés Français

The Minitel terminal is a small CRT monitor with a fold-down alphanumeric keyboard.
My Alcatel Minitel terminal

In the 1970s and 1980s, so-called videotext systems, terminal-based phoneline access to information services on central computers, were seen as an obvious next step for telephone network operators with an interest in profitable new products. In most countries this resulted in services such as the UK’s Prestel, a subscription service relying on costly hardware, but France Télécom instead pursued the bold path of making the terminals free to subscribers with free access to phone listings and yellow pages, but a business model based on pay-to-use premium services.

Thus, through the 1980s all French households had a Minitel terminal beside the phone, and the service became a runaway success. Ever since seeing Minitel terminals as a tourist I’d been fascinated by the service, so here in the 2020s when a friend was visiting their family in France I asked whether he could pick up an old Minitel terminal for me. Thus I found myself parting with around $25 and being rewarded with a slightly battered Minitel cardboard box containing one of the familiar brown Alcatel terminals. I certainly wasn’t expecting one in its original packaging. Continue reading “Teardown: Alcatel Telic 1 Minitel Terminal”

A Hombrew Retro Laptop

We feel bad when we see a retrocomputer project and think, “Hey! That’s not that old.” But, usually, when we think about it, it really is. Take the Penkesu. It looks like one of the little organizer computers that were popular — ok — a long time ago.

Inside is a Raspberry Pi Zero 2W, a 7.9 inch 400×1280 screen and a 48-key mechanical keyboard. Unsurprisingly, the case is mostly 3D printed, but it does use Gameboy Advance SP hinges.

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CX-6000 Pen Plotter Upgrade

[Terje Io] decided to breathe new life into an old pen plotter — the CX6000 from C. Itoh, a Japanese company that made several printers for Apple in the 1980s. He keeps most of the framework, but the electronics get a major overhaul. The old motors are replaced, the controller and motor drivers are modernized using a Raspberry Pi Pico and stepper motor drivers. After tending to other auxiliary electronics like the control panel and limit switches, it’s time to deal with the firmware.

Rather than reinvent the wheel, [Terje] sensibly built upon existing projects and refactored them for his application. G-Code processing is done by grblHAL, with an added mode to handle HPGL code. He modified the firmware from Motöri the Plotter project to parse HPGL, making his new CX6000+ bilingual.

We covered Motöri way back in 2009, and more recently we wrote about the Teensy Controller using grblHAL, one of the 32-bit big brothers of GRBL. Have you ever restored one of these old plotters? Or is it easier to just build your own these days?

It’s Always Floppy Time!

On [Jan Derogee]’s desk is something that wouldn’t look out of place for many of us, a pile of computer magazines with a case of 3.5″ floppy disks on top of it. The causal observer would see nothing more than the detritus of a retrocomputer enthusiast’s existence, but stick around. In fact it’s a clock, and one of the most unusual ones we’ve seen in a long time.

How can a box of floppies tell us the time? Selected disks have custom labels that look as though they might be authentic game collections, but in reality are fakes that carry numbers alongside the game art. An ingenious system of cams hidden in the hollowed out pile of magazines raises the correct floppies to tell the time, hours on the left row and minutes to the closest five minutes on the right. The floppies are modified by the removal of some plastic and the disk itself, because early versions had a habit of shredding disks. A final touch comes in the form of a Nokia phone on the desk next to the clock which plays a tune in lieu of chimes on the hour. You can see the clock in action in the video below the break.

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A computer program written in basic next to a modular synthesizer with many switches and lights

Modular Synth Pairs Perfectly With The Apple II

We have a soft spot for synthesizers – seriously, who doesn’t? So when [Joshua Coleman] combined his retro-looking DIY modular synth with the equally retro Apple II computer, we just had to share it with you.

The two machines are paired using a vintage digital-to-analog logic controller pack. This DAC was originally used to control model trains using your Apple II – something that we now desperately need to see in action. The pack can output voltages between 0 and 2.55 V at 8-bit resolution (or 256 steps), which is plenty for a retro synth.

With the card installed in Slot 7 of the Apple II and the DAC wired through to the synth’s CV/gate, it’s then a trivial matter of writing POKE statements in Applesoft BASIC to control the synth. The video after the break demonstrates playing a simple melody, as well as how one might use the Apple II keyboard to ‘play’ the synth in real time.

If you’re interested in building your own, the video below has all the information needed, as well as helpful advice on where to find a DAC for your preferred model of vintage computer. If all that doesn’t tickle your musical fancy, make sure to check out our coverage on the Game Boy MIDI synth, or perhaps this peculiar synth and visualizer combo.

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Commodore Promotional Film From 1984 Enhanced

Over on Retro Recipe’s YouTube channel, [Perifractic] has been busy restoring an old promotional video of how Commodore computers were made back in 1984 (video below the break). He cleaned up the old VHS-quality version that’s been around for years, translated the German to English, and trimmed some bits here and there. The result is a fascinating look into the MOS factory, Commodore’s German factory, and a few other facilities around the globe. The film shows the chip design engineers in action, wafer manufacturing, chip dicing, and some serious micro-probing of bare die. We also see PCB production, and final assembly, test and burn-in of Commodore PET and C64s in Germany.

Check out the video description, where [Perifractic] goes over the processes he used to clean up video and audio using machine learning. If restoration interests you, check out the piece we wrote about these techniques to restore old photographs last year. Are there any similar factory tour films, restored or not, lurking around the web? Let us know in the comments below.

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