Browse Prior Art Database

Reconfiguration of the Real Terminal in a Virtual Terminal Subsystem

IP.com Disclosure Number: IPCOM000039289D
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Flurry, GA: AUTHOR [+3]

Abstract

A method is described which permits dynamic changing of the devices comprising the real terminal, the characteristics of the real devices, and the default characteristics of the virtual terminals. Some workstations in computer systems have the ability to accept different hardware configurations (monochrome versus color display, mouse versus no mouse); however, changes must be made at the Initial Program Level (IPL). Some workstations allow changes to the real terminal characteristics, but only at IPL time. While this may be acceptable in some environments, requirements can change as a user changes tasks. Therefore, it is desirable to allow not only changes to the real terminal configuration in terms of the devices included, but also in terms of the characteristics of those devices, and other aspects of the real terminal.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 55% of the total text.

Page 1 of 2

Reconfiguration of the Real Terminal in a Virtual Terminal Subsystem

A method is described which permits dynamic changing of the devices comprising the real terminal, the characteristics of the real devices, and the default characteristics of the virtual terminals.

Some workstations in computer systems have the ability to accept different hardware configurations (monochrome versus color display, mouse versus no mouse); however, changes must be made at the Initial Program Level (IPL). Some workstations allow changes to the real terminal characteristics, but only at IPL time. While this may be acceptable in some environments, requirements can change as a user changes tasks. Therefore, it is desirable to allow not only changes to the real terminal configuration in terms of the devices included, but also in terms of the characteristics of those devices, and other aspects of the real terminal. The virtual terminal subsystem, in accordance with the new method, provides for reconfiguration of a real terminal. The reconfiguration is handled so that the virtual terminals, and the applications attached to them, need never know that any change has taken place. This is possible because the virtual terminals use "virtual devices" instead of real devices; thus the interface to any device of the same type is always the same. The Resource Controller, Common Device Utilities, and Virtual Display Driver components of the virtual terminal subsystem serve to insulate the virtual terminals from hardware dependencies and changes to the configuration of the real terminal or to changes to individual devices. An operating system may change certain devices in the configuration, certain characteristics of individual real devices and individual components of the Virtual Terminal Defaults by issuing the Send Command SVC with the reconfigure real devices option. Specifically, the operating system may: add a real locator to the real terminal, if one is

not already included,

add a sound device to the real terminal, if one is

not already included,

add a real display to the real terminal, as long

as the total number is less than the maximum

allowed,

delete a real display from the real ter...