301 Keyboard did not respond to software reset correctly, or a stuck
key failure was detected. If a stuck key was detected, the
scan code for the key is displayed in hexadecimal. For
example, the error code 49 301 indicates that key 73, the
PgUp key, has failed (49 hex = 73 decimal).
ff (Keyboard error)
Three common causes for keyboard error are: (i) several keys pressed simultaneously, (ii) keyboard buffer overflow, (iii) parity error on the serial line used by keyboard and keyboard controller for communication. The error reported is ff in scancode mode 1, and 00 in scancode modes 2 and 3. If translation is on, both 00 and ff are translated as ff.
FF Reset, Keyboard sends ACK and waits for system to receive it
then begins a program reset and Basic Assurance Test (BAT).
Keyboard returns a one byte completion code then sets default
Scan Code Set 2.
FF Key Detection Error or Overrun Error for Scan Code Set 2 or 3,
replaces last key in the keyboard buffer if the buffer is full.