When we say “Commodore,” we automatically think of the classic Commodore 64, but before it there was the Commodore PET, which arrived on the market in December 1977. Some enthusiasts see this computer as a greater challenge, and with that in mind, Thorbjörn Jemander decided to connect his own PET to the internet to play YouTube videos. Obviously, the project needs a bit of extra hardware, but a computer with over four decades on its shoulders doesn’t make things easy, to say the least…
How can we connect an old computer to the internet? The first logical step is to explore its interfaces, and in some cases backward compatibility is so broad that it’s not unusual to find machines running Windows 3.11 browsing the web. There are also more extreme examples, like a Commodore 64 sending tweets, but today we’re going further back, to the era of the Commodore PET.
The community has created all kinds of adapters and converters compatible with the PET, but Thorbjörn Jemander had the idea of connecting his own machine to the internet to watch YouTube videos. In addition to the natural limits of the PET’s interfaces, Thorbjörn also faces a lack of graphical resources. All he has to work with is a grid of 80 × 25 characters, or 60 kilobytes per second at 30 FPS….
How to Play YouTube Videos on a Commodore PET
Needless to say, a project with these characteristics requires additional hardware, and the Raspberry Pi Zero 2 W is an excellent candidate due to size and WiFi support. But excellent doesn’t mean perfect, and a good part of the challenge is getting the Pi to start the YouTube video, reduce its resolution to 640 × 200 pixels in grayscale, and transform each frame to 80 × 25.
The other half of the equation is that the PET receives those characters in its video memory fast enough. For that, Thorbjörn’s adapter uses 2 KB of SRAM, which allows the Raspberry Pi to store frames and prevent the Commodore PET from “choking.” After verifying that the video reaches 30 FPS with a local copy, Thorbjörn advanced in manufacturing the PCB, which wasn’t free of problems. A major error — (the Raspberry’s GPIO connector was upside down) — required a second revision, and with that detail fixed, the BlixTerm adapter became a reality.
The video is basically a 37-minute mini documentary that explains the entire technical process, but it’s worth watching from start to finish. Now, it’s inevitable to think that the Raspberry Pi Zero 2 W has hundreds of times the firepower of a Commodore PET; however, seeing two such different systems working together to play YouTube videos at 30 FPS is truly fascinating.
Sources: Thorbjörn Jemander, Hackaday
