PlayNET was an American online system for Commodore 64, launched in 1983. It used PETSCII and pixel graphics. It was bought by QuantumLink, who later turned into AOL.
h/t: Tim Koch
The Galaksija computer and the graphics part of its character set. Designed by Voja Antonic in Yugoslavia, 1983. Screenshots from games and an adaptation of the classic Dancing Demon animation.
Also check µGalaksija, a single-chip remake of the Galaksija.
La plissure du texte by Roy Ascott, 1983. A twelve-day project with artists in North America, Europe and Australia collaborating through the ARTEX network. Each participant took the role of a fairy tale character to create the story together.
Viewtron videotex system. Picture by DCvision2006 who dates the photo to 1980, but Viewtron was launched in 1983 according to Wikipedia.
Page from Snapshots by Mary Beams. Made with Norpak Telidon terminal in the early 80s. Image from the article Graphics Artistry On Line in BYTE Magazine 1983-07.