Hacking a weird TV censoring device

Timestamps:
0:00 - What is the TV Guardian
0:50 - Circuit board analysis
3:15 - Removing and connecting to the ROM
6:10 - Extracting data from the ROM
14:22 - Analyzing the contents of the ROM

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Special thanks to these supporters for making this video possible:
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[TechnologyConnections]

Well, this is ' delightful! A triumph for science. Thank you!

[bj_]

13:04 I don't know what I was expecting, but I've never seen a chip respond with such hostility to being probed

[ogami]

First Im like "oh, cool, this guy likes Technology Connections, he must be smart and cool". Then I'm impressed by your knowledge and soldering skills. Then I'm intimidated by your programming skills. Finally I am humbled by your other-worldly spreadsheet mastery. You're some sort of Nerd God.

[lordchiopet]

This feels like i asked a wizard a question and now I've been listening to them talk about things beyond mortal comprehension. Also huge props to maintaining the pacing of the video. This is slow stuff and keeping it snappy is really cool

[Eliasdbr]

Is anyone gonna mention the amount of skill this man has with spreadsheet functions?

[messyhair]

Ah, yes, my favorite classic film actor, Jerk van Gay

[Llohr]

This was a really elaborate way to slap a whole bunch of "bad words" in a youtube video. Nice work.

[jembawls]

Ben just casually talking Computer Science with all those words on the screen was too funny 😂

[yellowticket]

Can you imagine the guy who built and sold the TV Guardian, seeing a sudden jump in sales 30 years later...

[soobasis]

you are the only one who breaks down technology every bit by bit, just to let us understand. Thank you man, you are the best teacher.

[dundermifflinity]

Jerk van Gay made me laugh far more than it should have.
Great video. Hats off to you, sir.

[idkstudios]

I wanna see the TV attacker.
It just replaces every third word with obscenities.

[maurofoti]

In Technology Connection's video (at time 7:07), you can see that the Guardian removes articles attached to the foul word (in that cases it censores "What the fuck is that?" into "What is that?"). The whitelisted words are all articles (the, that, those) that would have to be removed to maintain the sense of the phrase. Probably for the microcontroller firmware, the fact that the word is whitelisted and has a substition bit (0x1) flags it as "if encountered before a foul work, also remove that article"

[jonathankorman]

It's hilarious to me that in the effort to keep (arbitrarily) naughty words out of one's home, you could buy a device that sat quietly in your home, secretly filled with profanities and blasphemy, whispering them to itself every cycle

[stephen]

Watched the original video on how it works. I think for “the”, if it is before a “naughty word”, it will eliminate it. So “what the f” just becomes “what”. But if no naughty word follows, then “the” is allowed. Possibly the 01 and 02 could indicate searching for a naughty word after or before the regular word. Hence “F you” would return blank, instead of “you”.

Now, with that said, if you enable write on the chip, you could create a reverse device that takes pg rated dialogue and spices it up a bit!

What does the other chip do?

[Enderbro]

I'm working with a lot of serial at my job recently and it feels so fucking cool to actually keep pace and understand COMPLETELY what you're doing.

[ikkuranus]

So, do you have any plans to modify the word list and make a follow-up video? I think it would be funny to have a TV guardian which replaces common words with profanity

[wayne_logan]

I started watching your videos about three years ago and my reaction was usually, "what sorcery is this!" I am now finishing my second year in electrical and electronics engineering (you can guess who is partly to blame for this decision 😂) and for the first time, I can say that I understood everything you did. You are such an inspiration. A role model too while at it. You sort of make embedded systems accessible en masse. Like an adult explaining a math problem to you, but it involves ICs and bitwise operations. lol ❤

[MrMegaManFan]

I’m a big fan of Technology Connections so even seeing this video 8 months after you made it, I still appreciate that you picked up on what he talked about and ran with it. Thank you!

[SonOfSofaman]

I got a kick out of Technology Connections' coverage of this device and was thrilled to see it examined further here. What a nostalgic surprise to learn a PIC is at its heart.

The reverse circuit engineering reminds me of the work Big Clive does on his channel. I wonder if we can get him to puzzle out the purpose of the comparator? Imagine that: my three favorite YT channels all dissecting the same device! A nerd's dream, come true.