0:41Ch                   Keyboard Buffer Tail Pointer

Length: 2 bytes

This word points to the location in the keyboard buffer at which the
next character typed will be placed. After a character is placed in
the keyboard at this location, the tail pointer is incremented and
adjusted if it needs to wrap to the beginning of the keyboard buffer.
If the tail pointer is equal to the head pointer (0:41Ah), the buffer
is empty.

See also: INT 16h, 00h
See also: 0:41Ah
See also: 0:41Eh
See also: 0:480h
See also: 0:482h

0:41Ch Keyboard Buffer Tail Pointer