INT 16 U - PCIBM PC Tools v5.1-8.0 DESKTOP - DISPLAY HELP LINE
	AX = FFF2h
	DS:SI -> ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. function key label string (each label preceded by '[')
		or help text
Return: AX destroyed
Notes:	available only when popped up
	if the specified string does not start with '[', it is displayed
	  centered on the bottom line, else the function key labels are shown