Since its first release seven years ago, Raspberry Pi single-board computers have become notoriously ubiquitous in compact and portable builds. They’re used in many different applications, but one of the most interesting has got to be how it can turn just about any old thing into a Linux computer. [xito666] writes in with his own build, a portable retro computer inspired by the retro-futuristic stylings of the Fallout games.
For true aesthetic accuracy, [xito666] used an old discarded Crown 5TV-65R portable TV and radio combo. The unit hails from the 1970s, so a bit newer than Vault technology, but it still gives off a great retro charm with its CRT screen and knobs. Sadly, the original components couldn’t be reused, and the shell was stripped empty so that the new hardware could take its place. This includes an off-the-shelf HDMI LCD screen with resistive touchscreen and new potentiometers and knobs that still fit in with the overall look of the machine.
What makes this build unique, however, is that it also includes custom software to turn it into a clock and music player, with the deliciously Pip Boy-like UI being controlled entirely with the front buttons and knobs. The whole project is well written up in the Reddit post, in it [xito666] explains some of their choices and planned improvements. One that we would suggest ourselves is replacing the menu scrolling selector dial with a rotary encoder rather than a potentiometer, for that added knob feel. We also think that with the addition of a keyboard, it would easily pass for one of those luggables from the 1980s, a style of project we’ve featured once or twice here before.
That poor CRT…
It was already dead
At a glance it looked like the project was driving a green phosphor CRT which would have been awesome for a Pi project.
Hearing that the whole thing got gutted is a bit of a downer. Then again, the reality of it is, driving the CRT probably would have been a nightmare without real high-voltage experience. Hearing about it would have been something SPECIAL.
On a Sony Watchman you can add a composite video input by lifting the output pin of the RF demodulator chip, and soldering your signal wire to the pad. The Pi can output this type of video signal if you don’t plug in an HDMI device.
Still, a neat project.
I wonder if you can squeeze in a switched 3.5 mm jack.
I tried a “is this display too tiny for anything” test a couple of months back where I stuck a TV joystick emulator video signal into a standalone RF modulator, then ran that through a 6dB TV amplifier to an indoor antenna and sat right in front of it with the telescopic out on the Watchman, and couldn’t see anything around channel 3 apart from a vaguely darker bit of interference snow, even with the telescopic touched to either side of the dipole. So I’m not sure what wasn’t working right. It was a quick and dirty lashup while I had several things to hand, and didn’t really have time at the time to troubleshoot it fully. It’s possible the TV amp had a high pass filter to cut FM and it killed channel 3. Also your average mostly UHF sized indoor TV antenna is gonna be sucktastic at 60ish Mhz.
I got what you’re generally talking about to work by opening the case and soldering a coax cable to the pads where the antenna was connected, then soldering the other side to the RF modulator. Ended up shielding it in a little tinfoil and putting it all inside the original case, with a hole dremeled out for the composite video input. The picture is surprisingly crisp. I can use it as a terminal and read the text pretty easily.
Funny, I just did that a month or two ago – put a composite BNC sticking out of a Watchman. I gave it to a video artist friend of mine, but it was almost usable as a Pi terminal.
I seem to recall that you’re only gonna have to deal with about 8kV in one that size, while the 12″ monochrome portables would have been around 12-15kV
Yip – 1kV per diagonal inch for a monochrome CRT – rule of thumb I read somewhere in the 80s
Nah, it’s not a nightmare. It’s pretty easy to drive a CRT. And the high-voltage safety is often overwrought. Unless it’s a reaaaal old monster of a CRT (like 1940s or something) then the high voltages don’t have enough energy to actually injure you. I’ve been bitten by dozens and dozens of CRTs and their associated circuitry. The paranoia about the HT side of the circuit actually blinds people to the far more rational risk: the side of the board that runs mains voltage, along with the capacitors in that power management circuitry. Those are what you really need to look out for, not the CRT anode or flyback transformer or any of that. If you’ve ever worked on mains/know how to discharge a cap with an old power resistor, then you are perfectly capable of handling CRT circuitry.
I’ve handled the deflection coils while live, swapping ’em back and forth to make a kind of crappy audio oscilloscope for shits and giggles. Holding wires in both hands, just like you aren’t supposed to. It tickles. Don’t try this—I am a stupid and stubborn yet somehow experienced man—but I can say for certain that most people’s fright is not really so warranted as they think.
https://lowendmac.com/2007/the-truth-about-crts-and-shock-danger/
I agree that this project would be way cooler if it actually used some old phosphor and glass—a little jar full of outer space and lightning bolts—than yet another LCD replacing a tube. But hey, he says it was already dead. Good use of the remaining hardware, still looks cool :)
I had decades of experience repairing CRT based electronics like TVs and projection units so I’m going to chime in here for a bit of balance.
Firstly your link is about CRT discharge and this is something that needs consideration although, I agree that it may not be the highest risk factor.
Secondly you mention deflection as though it’s harmless, perhaps you meant vertical deflection which is a relatively lower voltage. On the other hand horizontal deflection can be fatal. It’s a much higher voltage and current to overcome the high inductance at 15/16 kHz compared to vertical deflection at 50/60 Hz.
To a younger engineer, the electronics in a CRT device must look like it came from another planet.
You need to have some familiarity with the technology to work on it safely.
Firstly, if it’s mains powered and your not competent with mains powered devices then leave it alone. CRT devices are not entry level for mains power.
Understand these things first:
CRT discharge.
Hot (or live) chassis.
CRT HT voltage.
Horizontal deflection voltage.
Horizontal (chopper) and flyback drive voltage.
Crowbar circuit.
X radiation risk.
And also where all these things are and what components they relate to.
To be fair, though, the thing was a TV. All you’d need to do was find somewhere to inject the video. Everything else is already in there. It would’ve been MUCH better, a real CRT in a world of cheap LCDs.
Old NTSC TV usually have a 3 pin 6MHz ceramic filter at the composite output coming off the IF stage. It is usually buffered by something like an emitter follower before feeding into the colour decoding matrix. That’s where you can tap off the signal or inject your own.
Injecting a composite signal in an old TV set could be safe and easy. The biggest problem is on older sets that had an hot chassis directly connected to the mains voltage.
https://www.youtube.com/watch?v=_LRIzRyzDzA
Besisdes for a fallout style clock a crt is way cooler…
I used to have to hook my 8 bit up to one of those when I got kicked off the color TV
I had an older version of a portable Crown (Victor Corp) television 3 decades ago.
I never thought of keeping it, don’t know what happened to it.
(It did have a vertical linearity problem)
Raspberry Pi was release 8 years ago (2012). I went to Wikipedia to confirm the date and saw where 7 years ago comes from though.
Hack an echo show/spot, Homekit, Google, or others to have a fallout display, sounds. Might be worth something and more available
Is there any reason to use one of those AI assistants instead of, like… a pi? Or any other cheap gizmo that will loop a video and play sound? I don’t like to advocate the use of those things personally, but I am admittedly a bit of a crank.
Ya Party till the nukes drop