Editing Telidon (section)

===Telidon becomes NAPLPS===
{{Main|NAPLPS}}
AT&T started a standardization effort with Bell and the DoC.<ref name=b/> AT&T contributed two major additions to the system; the ability to define your own [[character set]]s, and the ability to wrap up multiple graphics commands into a "macro". The former provided not only or international characters, but also for the creation of small graphics that could be sent with a low transmission cost, which is useful in certain roles where the graphics can be arranged in a grid, like a chessboard. The later allowed the programmers to create a commonly used graphical element, the AT&T logo for instance, and save it to a macro. The graphic can then be recreated with a single instruction in any page that needed it.

The resulting system emerged in early 1983 as [[NAPLPS]], while the transmission method that encoded information into the [[vertical blank interrupt]] of a TV signal became the [[NABTS]] standard. Major articles in ''[[Byte (magazine)|Byte Magazine]]'' introduced the NAPLPS system to a wider audience, spread over a four-month period in the February, March, April, and May 1983 issues. With the standard complete, the U.S. teletext plans started moving forward. NAPLPS' ability to draw complex graphics was particularly interesting to U.S. information vendors such as Compuserve, as it allowed them to draw network or advertiser logos.<ref>Ed Ellers, [http://teletext.mb21.co.uk/gallery/world/usa/index.shtml "Teletext around the world"]</ref>

By this point the technical development of Telidon was complete, and that portion of the Canadian government's involvement wound down in the summer of 1983. Further efforts were aimed at helping develop a commercial marketplace for Telidon systems and content, running for another year.