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Terminal Support Using Device Characteristics

IP.com Disclosure Number: IPCOM000073484D
Original Publication Date: 1970-Dec-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Siegel, JJ: AUTHOR

Abstract

To support an intermix of terminals in a telecommunications control program, it is necessary to build a variety of channel programs to communicate with the devices. Previous implementation (BTAM/QTAM) used model channel program for each terminal type. Each terminal type (IBM/1050, 1060, 2780, etc.) had a separate device I/O module containing model CCW's to be used in channel program generation. This technique proved to be wasteful of core for a user with different but similar type terminals (eg. 1050, 2740, 83B3, etc.).

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Terminal Support Using Device Characteristics

To support an intermix of terminals in a telecommunications control program, it is necessary to build a variety of channel programs to communicate with the devices. Previous implementation (BTAM/QTAM) used model channel program for each terminal type. Each terminal type (IBM/1050, 1060, 2780, etc.) had a separate device I/O module containing model CCW's to be used in channel program generation. This technique proved to be wasteful of core for a user with different but similar type terminals (eg. 1050, 2740, 83B3, etc.).

By breaking out the basic characteristics of each terminal, it is possible to treat many apparently different terminal types as one "characteristically identical terminal type."

For example: terminals 1030, 1050, 1060, 2260 remote, 2740 polled, 83B3, 115A BSC polled devices all have identical polling sequences. Write EOT sequence Write polling characters Read response to polling.

This polling sequence characteristic can be represented by a bit in a device characteristics entry for these devices (each has a polling sequence). The difference between the terminals is in the actual characters used. By associating these special characters (EOT sequence, etc.) with the terminal types, the differences can be ignored for the polling. The CCW count used for special character sequences should be associated with the special characters themselves, not the basic characteristics.

Some of the basic terminal character...