Technology Reference Guide

	Technology Reference Guide 6. Terminal Emulation/Host Connectivity D. 525X Emulation

What is it?
The 5250-class family of devices is used on the IBM minicomputer systems, including the System 3X and AS/400. This device family includes terminals, printers and other devices that can interface through the 5250 connection. These IBM systems are smaller than mainframes, and are used as hosts in a small computing environment, or as departmental systems within a larger enterprise-wide context. 5250 devices are attached using a twinaxial cable, which has two center conductors instead of the one inside a coaxial cable.

What does it do?
5250 Terminal emulation provides the means to communicate as a terminal device with the System 3X and AS/400 systems. A standalone connection will require a 5250 interface card that provides the twinax cable connection, and emulation software to provide the communications protocols and session-management services needed. It is also possible to connect to these systems using a 5250 gateway on a PC LAN, where the PCs can use the network to access the gateway, and it, in turn, provides the 5250 connection to the IBM system. Emulation products are available for Macintosh and Windows platforms.

Since these systems are smaller and less complex than a mainframe, 5250 connections are usually made directly to an internal interface on the minicomputer, unless the number of connections required exceed the capacity of the internal interface.

How is it used?
5250 emulation provides the means for a PC to communicate with IBMs System 3X, and AS/400 systems. These systems are commonly found as departmental computers in large corporations, or the central hosts for smaller environments. As with any form of terminal emulation, it allows the PC to appear as a terminal to these systems, permitting the user to log into sessions, initiate processes, and transfer data back and forth.

The emulation software may also provide the ability to maintain multiple terminal sessions with several hosts, and may provide features that allow management of these multiple sessions, and file transfer capabilities.

Where do I get more information?
Contact your local CBV Office.