There was a time that the Commodore PET was the standard computer at North American schools. It’s all-in-one, rugged construction made it ideal for the education market and for some of us, the PET started a life-long love affair with computers. [Ruiz Brothers] at Adafruit has come up with a miniature PET model run on a microcontroller and loaded up with a green LED matrix for a true vintage look.
While not a working model of a PET, the model runs on an Adafruit Feather M0 Basic Proto which is an Atmel ATSAMD21 Cortex M0 microcontroller and can display graphics on Adafruit’s 16×9 charlieplexed led matrix.The ATSAMD21 is the chip used in the Arduino Zero, so I’m sure we’ll see more of this chip in the future. Like all of the tutorials at Adafruit, this one is very detailed with step-by-step animated pictures to help you along. Obviously, you don’t need the exact hardware that they’re using, but if you’re putting in an order from Adafruit anyway, why not?
The plans for the 3D printed PET are available for free, so even if you don’t want to put their LED matrix and microcontroller in it, you can still print yourself out a great looking prop and 3D printing the PET will only use about a dollar’s worth of filament. Of course, while this is a cool retro model, if you have a Commodore PET lying around, you could probably do something else with it. We don’t, so that sound you hear is the sound of our 3D printer printing up the past.
I for one welcome our new charlieplexed LED display overlords
omfg it’s so cute
It’s actually not the best 3D model of the PET I have seen. There are quite a few better ones on Thingiverse. I am particularly annoyed by their complete lack of a bottom section for the case. The angles are generally wrong and I can’t help feeling it just doesn’t look quite right.
THe IS31FL3731 looks like a normal multiplexing LED controller, not charlieplexing. IMO that’s the sane thing to do, because for a matrix of this size, charlieplexing would only allow a very low duty cycle.
Oh no, I am wrong. It is indeed using charlieplexing. Looks like a more clever implementation though, that lights more than one LED at a time.
Wonder how bad the flicker is. Most people doing videos have a really long shutter time so that the horrid flicker isnt visible in video. Charlieplexing has been terrible for it IME, I have a couple of LOL shields for the arduino that are just sitting unused because for any decent amount of LEDs on it looks more like a strobelight.
That one has a duty cycle of 1/9, which is the same as a conventional multiplexed matric.
Yes, but at what frequency.
About flicker… does any company sell ‘slow phosphor LEDs’ or similar?
Or should I just continue the glow-in-the-dark on them experiments?
Flicker bothers me and I want to make a bright, almost-white/greenish LED display. I’m thinking the heat will degrade the paint, my first try didn’t work well; probably cheap glow paint is the issue. All it seemed to do was make the diodes dimmer.
Your showing your age but talking about slow (High persistence) phosphor and I am showing my are by even making reference to that lol :)
How about a tiny PET emulator and a small LCD? Would need to use wireless keyboard as no one can make a tiny and useful working keyboard. Commodore tried that with the chiclet keyboard on their 2001 and it was very unpopular.
Or a mini CRT from an old camcorder viewfinder. :)
I still have one of those old handheld B&W TVs made obsolete by the move to digital.
That would be the “Pay no attention to the long CRT neck poking out the rear” version. ;) Or make a desk for it, mount the CRT vertically and use a mirror and small rear projection screen inside the housing.
LOL, the rare Commodore PET Mini Projection Screen version.
The mini CRT I’ve found in monochrome were like 4 or 5 inches deep (electron still need to travel through a few grids and either pass by internal deflection plates or external yoke). Nearly all of the color viewer I’ve found were LCD, never a tiny color CRT. I don’t think anyone made color CRT smaller than 4″ in any easy to find source.
Yeah, the one I have is way too long for something like this. Besides, the HV would probably kill the whole thing anyway.
There was at least one color CRT viewfinder.
https://www.youtube.com/watch?v=UMxCff1XP7I
Can you print the PET in PET?
+1 well done! ;-)
I’m thinking about one of those old calculator watches for a keyboard and a microSD slot for the tape images. Lunar Lander on the Pet was my GOTO game when I was a kid.
Hunt the Wumpus.
I feel a draft……
(Your move)
+1 the 6502 emulator. -> http://www.stm32duino.com/viewtopic.php?t=433&start=20 .. add one of those tiny 0.96″ OLED displays and then you are talking.. although a full 40×25 character PETSCII screen might be a little bit of a stretch.
I might try that though I was thinking making a slightly bigger one and stuff a Raspberry PI and a small LCD into it.
Too cute. Damn me being nearly penniless!
If someone could make one with a real 320×200 monochrome screen and space for an 80x100mm PCB inside, that’d be great for my L-Star project. ;-)
On a display there’s this that looks pretty close to a green screen crt.
http://topwaydisplays.eu/EN/LM320200AGG-monochrome-lcd-graphic-display-with-controller-320×200-dots::F00285::P004685/
Or fake it with a color one of similar but not exact resolution.
https://www.adafruit.com/products/1480
Error 404 because of the :: in the URL
People like me who actually read the RFC’s just laugh when a web designer does that.