deskthority

I apologize in advance for my ignorance.
I know old keyboards with the ps2 connector can be connected to USB using an adaptor.

How about old-style keyboards that have a cable connection that looks like a telephone jack? Is there a way to adapt or modify one of those to use with a modern computer?

Also a newbie.

Yes, there are adapters for those. I think some calls them "Soarer's Converter" but I'm not too sure on that.
I think the telephone jack is a terminal connector. I think.

idk can somebody else help this person?

Are you talking about an RJ45 connector? I believe orihalcon now sells converters for that, simply having the right plug does not mean it will necessarily work for your keyboard. It would be important to know which keyboard you are trying to convert first.

Depends on the protocol. If the keyboard is a model that's known to work with soarer's firmware (see- original Mac keyboard) or other sort of firmware, then yes. But if not, your best bet is to handwire it with a controller like the Teensy. Ask Matt3o about handwiring

The square ones are not called RJ45. That is a telephony standard for a specific connector and signalling. The connectors are called modular connectors.
Same thing with PS/2 and mini-DIN. PS/2 is the keyboard protocol. Mini-DIN is the connector.

Soarer's converter supports both the XT protocol (DIN), AT and PS/2 (same protocol but DIN or mini-DIN respectively), and IBMs terminal protocol (modular connector). All of these are variations of the same protocol but mutually incompatible in practice.
Some IBM Model M had detachable cables where the plug at the keyboard side look a little bit like the modular connectors but with a locking lever on both the left and the right side. Those connectors are called SDL.

There are also other types of keyboards that have connectors that look similar to the ones used for PCs and IBM keyboards (DIN, mini-DIN or modular connector) but which were made for other types of computers and are incompatible.
For instance, the first keyboards for the Macintosh had modular connectors. Later mac keyboards talked the ADB protocol with mini-DIN plugs.

Findecanor wrote: ↑The square ones are not called RJ45. That is a telephony standard for a specific connector and signalling. The connectors are called modular connectors.
Same thing with PS/2 and mini-DIN. PS/2 is the keyboard protocol. Mini-DIN is the connector.

Thanks for sharing that tidbit. Especially re: PS/2, I very often see it referred to as a connector rather than strictly just the protocol. Learn something new every day here.

I think there is something to be said for being careful with cables as some which are physically compatible are not always electrically compatible, but I think you're being a bit pedantic. For example, although ADB and S-Video are two different protocols, they both use the physically and electrically compatible mini-DIN-4 cables.

Findecanor wrote: ↑The square ones are not called RJ45. That is a telephony standard for a specific connector and signalling. The connectors are called modular connectors.

They are 4P4C modular connectors if you want to be truly pedantic .

Blaise170 wrote: ↑I think there is something to be said for being careful with cables as some which are physically compatible are not always electrically compatible, but I think you're being a bit pedantic.

Incorrect terminology is a pet peeve of mine. For instance it is extremely wide-spread to say "America" and mean a specific nation in America.

When buying used keyboards, well.. anything on eBay and similar sites .. you need to know your stuff because the people selling the things don't always do.
For instance, I have seen used keyboards for sale as "having PS/2 cable" when it was actually ADB. More commonly, people don't know the difference between a "mechanical" and non-mechanical keyboard or what "clicky" means — and they sometimes mislabel things intentionally because they can get away with it. You also see the "IBM" keyword a lot for non-IBM keyboards, only because the box the keyboard came in said "IBM-compatible" they can get away with it.
It isn't just old stuff: I have stopped counting how many "Apple Magic Keyboard" I have seen that aren't.

When it comes to cables, cables with modular connectors, DIN, mini-DIN or D-sub don't always have a wire for every pin in the connector. In a few cases, more often when there is the same plug in both ends, one or more wires may be crossed (often "receive" and "transmit" lines).
Many protocols require also that one or more pairs of wires are twisted in the wire and/or shielded. Higher-speed protocols and power delivery also require that individual wires are at least a certain thickness.
The trend changed in modern times to use unique connectors for specific protocols, such as in the case of USB, HDMI, etc,. but things have gone bad recently with USB Type C where for instance a cable that came with one phone is not safe to use for power delivery to a laptop etc.

Thanks, everyone for your great answers.
I see this is more complicated than I expected. The person who found the keyboards doesn't know much about their origins, he just told me about the phone-like connector. I have to wait until he mails them to me to have more information.