While not for PAL, as soon as I saw this question I thought of Don Lancaster's book from 1976 "The TV Typewriter Cookbook". There are various sites on the inter-webs that have complete scans of that book. I'm not linking to any as I don't know how legal they are.

@jsotola Points #2 and $6 of the Interlock description both refer to software as well as hardware

"A long series loop of switches will be plagued by false openings that shut off the equipment." I work in systems that have 20 to 30 E-Stop buttons in series and this architecture has easily been in use reliably for 30+ years, so I am not sure why you are experiencing what you state.

Given the age of the 8086, you might get a better answer on Retro Computing.SE. I've seen many answers where the information's provided with a historical context.

@Justme RS485 works on differential current flow. It shouldn't matter how the two devices are powered - as long s they are powered within specifications

You haven't provided details of your OLED display, but a quick google showed this site for what looks to be the unit you are using. In that example display.print() is using a ASCII string, but you seem to be sending raw values from 1..99 to that call. I would expect that you need to translate these numbers to ASCII strings before sending them to the display.

Given the website the OP provided, and their profile name, it's likely that they are not a native English speaker. So I'd cut them some slack in that area

Many events are won by single digit milliseconds /s

Such systems already exist. Scoring in the sport of Fencing has/is transitioned from wired to wireless, and I believe that the wireless systems are used at the Olympics.

Your solution would allow for the second person to press a button to be declared the winner. A presses button, and while A is transmitting, B presses button and garbles A's transmission. Then the random delay of B is less than that of A, B transmits again, causing B to "win" even though A responded first.

Regarding unplanned startups, I had the same experience with steel mills.

FYI What you are describing is a common practice called Single Wire Earth Return (SWER), see here for more info.

Hmm .. and how much does the helium cost? lol I'm saying this mostly in jest, but for an apples to apples comparison you do need to take in to account everything needed to create the equal magnetic fields. Which raise the question for me - could you even produce the same field strength of say an MRI machine with a resistive electromagnet? My gut feeling is probably no you can't.

Being a pedant, I have to ask how the power requirements for creating the cryogenic environment figure into the overall efficiency of a superconducting coil /s

I think you are asking if you can program an NFC tag to not transmit an empty tag back to the reader. Is that correct?

The code in that example hurts my eyes!

In terms of the OP's desire to light only 3 LEDs, would you simply for example connect the cathode of the Green LED in common to pins 1, 8, 17, and 16 etc?