Browse Prior Art Database

Enhanced Functions For Videotex Terminals

IP.com Disclosure Number: IPCOM000048478D
Original Publication Date: 1982-Feb-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 4 page(s) / 51K

Publishing Venue

IBM

Related People

Evangelisti, CJ: AUTHOR [+2]

Abstract

In existing videotex systems, e.g., the PRESTEL service provided by the British Post Office, three types of keyboards are available: the editor's keyboard used by information providers to enter information, the business keyboard which provides for limited data entry capability, and the hand held keypad used by users who need only a menu-guided retrieval function capability. The enhancement of the hand-held keypads used with such videotex systems is described herein which provides additional services to the user.

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Enhanced Functions For Videotex Terminals

In existing videotex systems, e.g., the PRESTEL service provided by the British Post Office, three types of keyboards are available: the editor's keyboard used by information providers to enter information, the business keyboard which provides for limited data entry capability, and the hand held keypad used by users who need only a menu-guided retrieval function capability. The enhancement of the hand-held keypads used with such videotex systems is described herein which provides additional services to the user.

With currently available hand-held keypads, there are 12 keys corresponding to the ten decimal digits (0-9) and two special characters '#' and '*'. With these 12 keys the user is Limited to specifying (a) page numbers, (b) choices of a frame currently being viewed, (c) re-transmission or re-access of current frame which may have been corrupted during transmission and (d) transmission of up to three frames viewed immediately prior to the currently viewed frame. The search for information of specific interest to the user is aided by menus which are displayed in many frames called routing frames. A typical access to information might include traversal through several routing frames before finally reaching the frame with the relevant information. One of the desirable features would be for the user to be able to recall, on a local basis, all or at least a subset of the routing frames without re-traversing the access path from the beginning of the information base. This recall capability would enable the user to rapidly scan several alternative paths in an information base without incurring access charges on the service machine and transmission charges over the telephone lines.

This article proposes a recall capability and shows how it could be integrated with existing keypads. MODE FUNCTION: The existing keypad is augmented by an additional key which is called the 'mode' key. Two modes of operation are defined: a local mode and an 'on-line' mode. Each time the mode key is pressed, the mode is switched from local to on-line or from on-line to local depending on the current mode. Appropriate sensory feedback is provided to the user to indicate the current mode.

In the on-line mode, the operation of the keypad is identical to an existing keypad. In addition, frames that are received from a service machine, may be stored in the terminal's local memory. Precisely which frames are stored and where they are stored in the memory are determined by the user. In the local mode, the user may manipulate the contents of the local storage in ways that will be explained below. For the sake of ease of description we shall assume that the local memory has a 4-frame capacity. In practice, the number of frames stored locally would be dictated by economic considerations.

OVERLAY FUNCTION: The local memory is managed as a stack with four elements. Normally, a frame that is received from the service machine (...