INT 21,44,6 / IOCTL,6 - Get Input Status

AH = 44h

AL = 06

BX = handle

on return

CF = 0 if successful

= 1 if error

AX = error code if CF set (see ~DOS ERROR CODES~)

AL = 00 if EOF (files), or not ready (char devices)

= FF if not EOF (files), or ready (char devices)

- used to determine if a file or device is ready for input

- can be used to determine EOF unless EOF caused by ~INT 21,42~