Int 21 Fn 4410 - Dos 5+ - Ioctl - Query Generic Ioctl Capability (handle [D]
AX = 4410h
BX = handle for device
CH = category code (see #1232)
CL = function code (see #1233)
Return: CF clear if successful
AX = 0000h specified IOCTL function is supported
CF set on error
AL = 01h IOCTL capability not available
Note: a program which wishes to use Generic IOCTL calls beyond those in the
standard DOS 3.2 set may use this call first to see whether a
particular call is supported
See Also: AX=440Ch,AX=440Dh"DOS 3.2+",AX=4411h