INT 21,44,1 / IOCTL,1 - Set Device Information
AH = 44h
AL = 01
BX = handle
DH = must be zero
DL = device data low order byte (see below)
on return
AX = error code if CF set
DX = device information (see below)
- applicable to character devices only
- allows setting of device data word for character devices
- usually used to change from binary to translated I/O
- handle in BX must be an opened file or device
Device Data Word
|F|E|D|C|B|A|9|8|7|6|5|4|3|2|1|0| Device Data Word
| | | | | | | | | | | | | | | `---- 1 = standard input device
| | | | | | | | | | | | | | `---- 1 = standard output device
| | | | | | | | | | | | | `---- 1 = NUL device
| | | | | | | | | | | | `---- 1 = clock device
| | | | | | | | | | | `---- reserved
| | | | | | | | | | `---- 1 = binary mode, 0 = translated
| | | | | | | | | `---- 0 = end of file on input
| | | | | | | | `---- 1 = character device
`------------------ reserved, must be zero