IBM 5150 - Keyboard support
What was supplied
The keyboard that IBM supplied with the IBM 5150 is pictured at here. In IBM's later technical documentation, it is referred to as the '83-key keyboard'.
( Later, when IBM introduced the IBM 5160 [IBM XT], the same keyboard was used. )
AT-class keyboards are not useable
When IBM introduced the IBM 5170 (IBM AT), they also introduced a new keyboard protocol, put into both the new 84-key keyboard and the 5170 motherboard.
The 5170's 84-key keyboard (only supports the AT protocol) is not useable with the IBM 5150.
An option for the IBM 5150 is a third-party keyboard that can be switched between the different keyboard protocols. Example at here.
Another option is to use an AT-class keyboard together with an adapter that converts the AT keyboard protocol to a protocol that the 5150's motherboard recognises. Example at here.
Be wary if you hear that the auto-switching versions of IBM 101-key keyboards will work with the IBM 5150. I write that because I have a particular auto-switching IBM 101-key keyboard, the 52G9658, and although it works attached to my 5160s, it does not work attached to my 5150s.
The, "(as with all three ROM versions of the IBM PC)" shown at here, suggests an incompatibility.
If you are planning on buying one of these for use with your IBM 5150, get some form of guarantee that the particular unit for sale, does work with the 5150 (or get a money back guarantee). Note that any LEDs will not work, and the F11 and F12 keys are not expected to work.