Page:Login USENIX Newsletter feb1983.djvu/7

;login: Draft Standard Videotex/Teletext Presentation Level Protocol Syntax Available for Review BSR X3.110-198X, the draft proposed American National Standard Videotex/Teletext Presenta- tion Level Protocol Syntax (North American PLPS) is beginning a four-month ANSI public comment period which ends May 21, 1983. Copies of the draft standard (referred to as BSR X3.110 or more simply as NAPLPS) are available for $18 along with your mailing label from: X3 Secretariat CBEMA 311 First Street, N.W., Suite 500 Washington DC 20001 Brief Description of NAPLPS Videotex and Teletext services are envisioned as two-way and one-way services, respectively, pro- viding users with access to “pages” or “frames” that include alphanumeric text and pictorial informa- tion. NAPLPS is an information interchange standard that specifies the formats, rules, and procedures for the encoding of this information for Videotex and Teletext services in 7-bit and/or 8-bit bytes. NAPLPS capabilities include alphanumeric text supporting 40 Latin-based languages, a dynamically redefinable character set (DRCS), mosaic picture elements, picture description instructions (PDI), and macro definitions. Additional capabilities include color mapping, a controllable stroke width, continu- ous character scaling, programmable texture masks, unprotected fields, partial screen scrolling, and incremental encoding for highly compact descriptions of certain classes of images. NAPLPS is an information interchange standard that permits Videotex and Teletext information and transaction service providers and equipment manufacturers to develop their products according to an agreed interchange format. Without such agreements, information providers, service providers, and terminal manufacturers would not be willing to make the initial and continuing investments that are necessary for Videotex and Teletext services to become widely used. NAPLPS is the first interchange standard providing “blind interchange” which is desirable for electronic media envisioned for Videotex and Teletext. Blind interchange means that the sender and receiver of the information do not need any prior agreements or negotiation dialogue in order to mean- ingfully interchange information, except the agreement to conform to the standard. The conformance requirements specified here can be generally described as defining the rules (syntax) for conforming interchange at the coding interface; as well as the execution (semantics) to be applied by a conforming presentation process. For more information regarding the NAPLPS or membership on X3L2.1, please contact: Thomas N. Hastings, Chair X3L2 Digital Equipment Corporation 146 Main Street, ML1-2/H26 Maynard, MA 01754 (617) 493-8109 Volume 8, Number 1 March 1983 7