NAPLPS Technical Information

1. About NAPLPS

NAPLPS(North American Presentation Level Protocol Syntax) is an international standard for Videotex service . AT&T(American Telephone and Telegram) expanded the PLP(Presentation Level Protocol) to North American standards. (PLP was developed by the Telidon System, which was a project of the Canadian Government.)

Macro, DRCS(Dynamically Redefinable Character Set) and Mosaic Text functions are expanded to NAPLPS from PDI(Picture Description Instructions) of the Telidon System.

In Japan, NAPLPS JAPANESE LANGUAGE was enacted in Sepetember 1987.

Simply put, NAPLPS is one of the Videotex text and picture transfer methods.

2. Features of NAPLPS

(1) Protocol of international availability

It is a worldwide picture communication method, suitable for the contemporary Internet era.

(2) Excellent picture transfer efficiency

NAPLPS pictures are transfered in alpha geometric data instead of bitmap image. Alpha Geometric means transferring the text in the pictures as character codes and the geometric figures (dot, line, circle, etc..) as functional commands. Therefore, comparatively more pictures can be transferred even when the transfer speed is slow. This is a marked merit in sometimes overcrowded Internet sphere.

(3) Utilizing the display terminal capability

Since drawing is executed on the display side of the computer, graphic resolution changes can be made flexibly.

(4) Various expressions with color control

By utilizing color change and color blink, more varied expressions are possible with few colors.

(5) Dynamic picture drawing

Graphics can even be drawed while in the process of data transfer. This is because NAPLPS pictures are realized as data being progressively received, even with a low speed network. By applying this capability to data, which varyies with time (for example weather observation data), the latest information can be displayed at all times by transfering the data in the NAPLPS form.

3. NAPLPS Viewer Plugin

UCL provides NAPLPS Viewer Plugin decoding and realizing NAPLPS data.
The followings are features of the plug-in.

(1) Multi Platform

Will display NAPLPS pictures on various platforms as Netscape Navigator plug-in.

(2) Compatible with Full Color Environment

It is equipped with a virtual color palette allowing color change and color blink in Full Color (more than 256 color) environment. This function is not available for UNIX version yet, so the UNIX version will displays NAPLPS picture in an environment with 256 colors.

(3) Idle Blink

This function is available in Windows95 environment only.It allows color blink on a continuous idling cycle even after NAPLPS data decoding.

To download the personal version the NAPLPS Viewer Plugin, click here.

4. NAPLPS Tools

(1) NAPLPS Editor

Editor Screen

Editor Command list:

[DRAW]: Graphical drawing elements can be entered such as Point, Line, Polyline, Polygon, Rectangle, Circle(diameter), Circle(radius), Semicircle, Arc, Ellipse and Curve.
[TEXT]: Enter text or set the text field frame.
[SPECIAL]: Perform resets, clear the screen, run a macro, import an image, move coordinates, etc.
[DEFINE]: Declare a Macro,Texture,DRCS definition or the end of a definition.
[SYSTEM]: Initialize NAPLPS data and editing environment, change the current Screen Ratio, etc.
[EDIT]: Edit the drawings or texts after they have been entered.
[SEARCH]: Search for a text string of entered commands.
[BLOCK]: Designate a block of data, and perform various graphical operations(Move,Copy,Resize, etc.) on it.
[VIEW]: Play entered commands and display the contents of a file or a entered commands.
[FILE]: Load, save, or browse a PDI file.

(2) NAPLPS Data Converter

Converts other data formats(WMF,GIF, etc.) to the NAPLPS data format

(3) NAPLPS Viewer Library

Library functions to viewing the NAPLPS data for the C-language, etc.

Sample of Expand the the NAPLPS Text Drawing Effectiveness with the Windows TrueType Font:

Sample of Combination Effectiveness with Embeded Windows Multimedia(MCI) Commands(Image,Sound,Video...) into the NAPLPS Data

(4) NAPLPS Generation Library

Library functions to generating the NAPLPS data for the C-language, etc.

5. NAPLPS Application

Realtime weather monitoring

6. Future NAPLPS Extensions

Compatible with ActiveX
3 Dimensional display(DirectX, OpenGL)
Expression of various colors over 16 colors
Interactive entering function
Bi-directional information exchange(like DDE)
Java version
NAPLPS oriented Web page creation

7. NAPLPS Sample Pictures

Sample pictures are here.

8. NAPLPS Related Sites

CALAT home page - "CALAT: A Distributed Intelligent CAI System" The graphics in CALAT make use of NAPLPS.

9. Reference Documents

ANSI(American National Standard Institute) X3.110-1983 "Videotex/Teletext Presentation Level Protocol syntax(North American PLPS)"
CSA(Canadian Standard Association) T500-1983 "Videotex/Teletext Presentation Level Protocol syntax(North American PLPS)"
ITU-T(International Telecommunication Union-Telecommunication Standardization Sector, ex CCITT)T.101 "International interworking for videotex services DATA SYNTAX III"
JIS-INSTAC(Japan Industrial Standards-Information Technology Research and Standardization Center) TR001-1987 "NAPLPS JAPANESE LANGUAGE"
RFC(Request for Comments) 0965 "A Format for a Graphical Communication Protocol"
RFC 1345 "Character Mnemonics & Character Sets"