ctty MS-DOS Command

Type: Internal (2.0 and later)

Syntax:

CTTY (device)

Purpose: Changes the standard I/O (Input/Output) device to an auxiliary device.

Discussion

The CTTY command is used only for I/O (input/output) devices such as a monitor. It cannot be used for peripheral devices such as a printer. However, DOS does not check to make sure you have entered a valid device name. If, for example, you specify a printer, DOS will attempt to read from the device, producing an error condition. Affects only programs that use standard DOS calls. BASIC and other programs that do not access I/O devices with DOS calls will not recognize device changes reset using this command. Valid device names are: AUX LPT CLOCK$ LST COM NUL CON PRN

Example

To change to another I/O device using the AUX port, enter ctty aux To change back to the standard I/O device enter ctty con