If you have ever utilized a property pc from the late 1970s or early 1980s, you are going to no question be common with the gradual pace of their user interfaces. Even listing the contents of a Basic method from RAM could consider many seconds, with the display updating a single line at a time. Movie online games were being wholly optimized for velocity, but could however deal with just a several slowly and gradually-relocating objects at the very same time. Clearly, enjoying something resembling total-motion video on hardware from that period would be absolutely impossible – or so you may possibly feel.
In truth, [Thorbjörn Jemander] has managed to persuade a Commodore PET to engage in YouTube videos at a fully fair 30 frames for every 2nd. He describes the course of action of creating the “BlixTerm” components and application in his online video (embedded underneath), alongside with heaps of helpful information and facts on how to drive digital devices to their absolute limits.
Obviously, the PET demands a bit of support from fashionable hardware, in this scenario a Raspberry Pi Zero 2 W hooked up to the “User” growth port. The Pi connects to YouTube as a result of WiFi and hundreds the asked for video clip, then downconverts it to a 640×200 grayscale stream and transforms each and every frame to an 80×25 grid of people, working with people from the PET’s ROM that most closely resemble the sample wanted.
Though it took quite some work to squeeze more than enough general performance out of the Pi to do all of this in true time, the trickiest bit was finding the resulting character stream into the PET’s video memory rapidly adequate. To do this, [Thorbjörn] designed a special interface card with 2 KB of twin-port SRAM, which enabled the Pi to retail store its online video frames as soon as they have been all set on one particular side, and the PET to load them at its own pace from the other facet. With just sixteen microseconds available to procedure every byte, the PET’s CPU can execute only four or 5 device code guidelines barely more than enough to load and retail outlet a one character and soar to the up coming memory deal with.
The conclusion result, as you can see in the video, is truly amazing. Even within just the constraints of the Commodore character set, the ensuing impression is clearly recognizable, when the body level would seem to defy the hardware’s constraints.
If you’re a Commodore aficionado and asking yourself what the hell that strange PET 600 model is all about, [Thorbjörn] produced a video about that much too it’s a rebadged 8296 aimed at the Swedish sector. We’ve really found a challenge to make reside online video on the PET just before, even though at a significantly decrease body amount. Many thanks for the suggestion, [Keith Olson]!
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