Browse Prior Art Database

Dynamic Keyboard Translation During Communication Between Terminals

IP.com Disclosure Number: IPCOM000048709D
Original Publication Date: 1982-Mar-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 3 page(s) / 57K

Publishing Venue

IBM

Related People

Baird, SK: AUTHOR [+2]

Abstract

During a communication session between two or more terminals, data from one of the communicating terminals must be translated from an internal representation into appropriate line code format based upon a specific keyboard. The present system provides an approach in communication of dynamically constructing a selected keyboard from one of sixty possible keyboards for the communicating terminal so that the communicated information is properly displayed. In order to select the appropriate I/O keyboard, the present approach involves a system wherein a shell or core table of about 75 characters common to all keyboards is stored. The other 20 variable character translations are dynamically constructed dependent upon the type of keyboard which is being used in the specific communication system.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Dynamic Keyboard Translation During Communication Between Terminals

During a communication session between two or more terminals, data from one of the communicating terminals must be translated from an internal representation into appropriate line code format based upon a specific keyboard. The present system provides an approach in communication of dynamically constructing a selected keyboard from one of sixty possible keyboards for the communicating terminal so that the communicated information is properly displayed. In order to select the appropriate I/O keyboard, the present approach involves a system wherein a shell or core table of about 75 characters common to all keyboards is stored. The other 20 variable character translations are dynamically constructed dependent upon the type of keyboard which is being used in the specific communication system.

By way of background, in the present state of the art, the number of characters available on new, high function text processing systems far exceeds the capability of six and seven bit line codes used for data transfer when communicating with these systems. A common remedy for this problem is the use of translate tables which map each line code into a specific internal code depending on the character set of the active keyboard. One obvious organization of the table is to have resident in memory translate tables for each supported keyboard. However, due to memory constraints this is impractical because of the large number of keyboards available. The present system allows for translation of the data stream with translate tables for only the active keyboard in memory at any time, but also has in memory other tables that can be used to reconstruct the translate tables for any supported keyboard at the time an alternate selection is made.

To facilitate fast execution during data transfer, the translate algorithm is kept simple. The tables are constructed so that a one-step lookup is sufficient for receive data and a two-step lookup for send data is required.

Instead of separate translate tables for each available keyboard, tables are resident in memory that are used to reconstruct the necessary translate tables at the time an alternate choice is made. Thus, only one send and one receive table exists at any time. Upon notice of a keyboard change, the algorithm begins with "shells" for the send and receive tables and fills in entries that are variable among the keyboards to accomplish this, with reference to the figure, the following additional tables are necessary:
1. Variant On Line Table (VOL)

This table consists of the line codes which must be mapped

into various characters depending on the current keyboard.
2. Variant Graphics Table (VG)

These tables consist of the reorder numbers for all the

variant characters available on a certain keyboard. There

must be a VG table for each of the supported keyboards.
3. Reorder Number Table (R...