the Jetdirect autoswitch was introduced. 1998 also saw the release of 170x, the first value-line print server aimed at smaller companies that did not necessarily need full networking - only TCP/IP or IPX/SPX support. This was followed in 2000 by the Jetdirect 70x home print server. Protocols More advanced versions of JetDirect supported a number of network printing protocols. However, the protocol that ended up being associated with it, the JetDirect protocol, is its raw TCP/IP protocol sometimes referred to as Socket API or RAW. It is an extremely simple network printing protocol. Submitting a print job can be done by netcating a file containing the page description language (e.g. PostScript, PCL) to the appropriate TCP port on the printer (default port is 9100). Information about the printer and job is simply sent to the client while the TCP connection is active. The port would reject connections if printer is busy. AppSocket is a very similar implementation by Tektronix for Phaser printers, later sold to Xerox. This protocol adds support for querying for printer status by non-printing users via a separate UDP port. Most JetDirect devices also came with, JetDirect Interface, a telnet interface for configuring the device or printer. External print servers Internal print servers MIO MIO (Modular Input/Output) was the first technology developed by HP for its laser printers to enable the addition of peripheral cards such as Jetdirect. LIO LIO (Low-end I/O) interfaces were developed by HP as a corporate response to the strictly internal MIO and EIO development path. The LIO interface differs from MIO/EIO in that the card is wrapped in an external plastic casing and is hot-swappable. The LIO backplane technology is based on a low power/low-voltage (< 1-volt) differential signaling technology. 200N (C6502a) - Parallel with Centronics Interface 200m (J6039C) – 10/100 BASE-T (Supports only Windows and Apple Mac, fixed firmware) 250m (J6042B) – 10/100 BASE-T (Full support for Netware and Unix, firmware upgradeable) 280m (J6044A) – 802.11b Wireless EIO EIO (Enhanced Input/Output) is a modular interface developed by HP for its printers to expand their capabilities. EIO does not just serve Jetdirect cards, but EIO hard drives and the EIO Connectivity card for adding communication ports to the printers as well. EIO utilizes the 3.3V signaling technology of the Conventional PCI bus and is significantly more energy-efficient than MIO technology. EIO print servers will not work in LIO slots, nor will the