INT 1A - WORD PERFECT v5.0 Third Party Interface - INSTALLATION CHECK
AX = 3601h
Return: DS:SI = routine to monitor keyboard input, immediately preceded by the
ASCIZ string "WPCORP\0"
Notes:  WordPerfect 5.0 will call this interrupt at start up to determine if a
third party product wants to interface with it.  The third party
product must intercept this interrupt and return the address of a
keyboard monitor routine.
Before checking for keyboard input, and after every key entered by the
user, Word Perfect will call the routine whose address was provided
in DS:SI with the following parameters:
Entry:  AX = key code or 0
BX = WordPerfect state flag
Exit:   AX = 0 or key code
BX = 0 or segment address of buffer with key codes
See the "WordPerfect 5.0 Developer's Toolkit" for further information.

See also: 165500

1A3601 - WORD PERFECT v5.0 Third Party Interface - INSTALLATION CHECK