For a USB keyboard that comes with its own USB to PS2 adapter, is there any reason why it would not work with an AT keyboard if I add a PS2 to AT adapter to the end of the chain?
ie. USB Keyboard -> PS2 -> AT
For ps/2 to AT there's only a different connector. Electrically they are the same, including signalling.
So if the keyboard works with a regular ps/2 pretty there's not a single reason a passive AT converter wouldn't.
Stuck at 10MHz...
I do not think that is entirely true. Reverse example: My Asrock Z370 board has a Ps2 KB port but I find no older AT KB with adapter to PS2 has worked yet.
Have not researched it much but read that later PS2 accepted different clock rates than older AT keyboards, so if the older AT KB did not accept a variant of clock then then it would not function proper.
If this is wrong sorry, I tried back in 2018 when I got the board with zero success but might have been some other issue...
Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun
It has worked every time I tried.🤷♂️
Horun wrote on 2022-07-30, 23:34:I do not think that is entirely true. Reverse example: My Asrock Z370 board has a Ps2 KB port but I find no older AT KB with adapter to PS2 has worked yet.
Have not researched it much but read that later PS2 accepted different clock rates than older AT keyboards, so if the older AT KB did not accept a variant of clock then then it would not function proper.
If this is wrong sorry, I tried back in 2018 when I got the board with zero success but might have been some other issue...
I have a couple of BTC 5100C mini keyboards. They worked perfectly until I got a relatively new motherboard with a PS/2 port that refused to detect them. At that point I remembered a weird hack for Model M keyboards, by soldering two 4.7k resistors as pull-up on the Clock and Data lines. Tried the same on one of my keyboards and it springed back to life. Maybe you could check this out next time...?
