Through bidirectional parallel communication, Windows 95 detects Plug and Play-compliant printers that return device ID values (as described in the IEEE 1284 specification). This feature allows applications to query the printer directly to find out about its physical attributes.
Bidirectional communication provides the benefit of configuring device driver settings on the server without user intervention. The printer driver can automatically determine how much memory the printer has, what device fonts are available, and so on.
Bidirectional communication also allows printers to send unsolicited messages to Windows 95 and to applications. For example, the printer might send an "out of paper" or "printer offline" message. Bidirectional communication enables much more detailed status reporting on a wider variety of information, such as low toner conditions, paper jams, maintenance needs, and so on.
To use bidirectional printing, you must have the following: