Before text editors existed, computer text was punched into punched cards with keypunch machines. The text was carried as a physical box of these thin cardboard cards, and read into a card-reader. The first text editors were line editors oriented on typewriter style terminals and they did not provide a window or screen-oriented display. They usually had very short commands (to minimize typing) that reproduced the current line. Among them were a command to print a selected section(s) of the file on the typewriter (or printer) in case of necessity. An "edit cursor", an imaginary insertion point, could be moved by special commands that operated with line numbers of specific text strings (context). Later, the context strings were extended to regular expressions. To see the changes, the file needed to be printed on the printer. These "line-based text editors" were considered revolutionary improvements over keypunch machines. In case typewriter-based terminals were not available, they were adapted to keypunch equipment. In this case the user needed to punch the commands into the separate deck of cards and feed them into the computer in order to edit the file. When computer terminals with video screens became available, screen-based text editors became common. One of the earliest "full screen" editors was O26 - which was written for the operator console of the CDC 6000 series machines in 1967. Another early full screen editor is vi. Written in the 1970s, vi is still a standard editor[1] for Unix and Linux operating systems. The productivity of editing using full-screen editors (compared to the line-based editors) motivated many of the early purchases of video terminals.