INT 15 - Rational Systems DOS/4GW - INSTALLATION CHECK
AX = BFDCh
DX = 0000h
SI = 0000h
Return: DX = nonzero if installed
DX:SI -> XBRK structure (see AX=BF02h)

See also: 15BF02

15BFDCDX0000 - Rational Systems DOS/4GW - INSTALLATION CHECK