INT 16 - PC Tools v5.1+ DESKTOP API - CHECK WHETHER DESKTOP LOADED RESIDENT
AX = FFC5h
Return: BL = nonzero if loaded resident
= 00h if nonresident
Note:   available only when popped up; should call AX=FFEFh first to ensure
that DESKTOP is active
SeeAlso: AX=FFF3h

See also: 16FFEF

16FFC5 - PC Tools v5.1+ DESKTOP API - CHECK WHETHER DESKTOP LOADED RESIDENT