Newly manufactured true AT and PS/2 keyboards were rare even 20 years ago. The cheap keyboards from even that time implement only the subset of behavior of true

Newly manufactured true AT and PS/2 keyboards were rare even 20 years ago. The cheap keyboards from even that time implement only the subset of behavior of true AT keyboard required for PC with OS that leaves the hardware in PC-like state. These keyboards tend to confuse the hell out from various 90's RISC workstations (SGI, DEC…) that also use PS/2 interface.