INT 2F - DOS 4.00 GRAPHICS.COM - INSTALLATION CHECK
AX = 1500h
Return: AX = FFFFh
ES:DI -> ??? (graphics data?)
Note:   this installation check conflicts with the CD-ROM Extensions
installation check; moved to AX=AC00h in later versions

See also: 2FAC00

2F1500 - DOS 4.00 GRAPHICS.COM - INSTALLATION CHECK