Compucolor character set

Revision as of 15:17, 25 December 2012

Compucolor was a late-1970s computer manufacturer whose most popular model was the Compucolor II, released in 1978. They had an earlier model, variously known as the Compucolor 8001 or Compucolor I, in 1976, and before that the Intecolor 8001 intelligent terminal.

The Compucolor computers and terminals used a slightly quirky character set based on ASCII, which contained only uppercase letters and most of the punctuation and mathematical characters, but replaced the lowercase letters with graphic characters. The control characters also had graphical renditions, though you probably had to poke them directly into screen memory to see them, since those characters, when typed or sent in an input/output stream, were used as control codes. The control-code meanings differed considerably from the standard ASCII C0 controls, with a few having more-or-less standard meanings (e.g., TAB, CR, LF, and BEL; though some of the references say that BEL, Ctrl-G, is not used even though it's noted on the "G" key on the keyboard), but most having platform-specific meanings such as changing the color of text. Still more control functions were accessed by escape sequences consisting of the ESC character followed by another character.

Due to the way CR and LF were defined on the Compucolor, you needed both CR and LF to break a line. The way it's worded in the manual, it appears they expect those characters to be output in the order LF+CR, which is backward from the more common CR+LF line break.

Some of the Compucolor manuals, in contrast to the main instruction manual, do mention lowercase letters in the standard ASCII positions, so perhaps there are modes which use them.

Documentation

• Compucolor II manual; has character set chart and description of control and escape codes
• Compucolor II programming manual rev 1
• Compucolor II Programming manual rev 2
• More Compucolor info