Text editor on IBM mainframe written at Cambridge University, UK
Author: Philip Hazel Specifications: http://www.srcf.ucam.org/cucps/19981999/speczed.htm Download: http://sites.google.com/site/texteditors/Home/files/ZED-dist.tar.gz (IBM 370 Assembler code) Family: MainframeEditorFamily Platform: Phoenix (IBM Mainframe OS) License: GPL v2
"ZED is a text editor that processes sequential files line by line under the control of EDITING COMMANDS. As ZED moves through the input, or SOURCE file, lines which have been passed (and possibly altered) are written out to a sequential output file, the DESTINATION. The effect of a ZED run is therefore to make a copy of the source, with changes as requested by the editing commands.
Although the source is normally processed in a forward sequential manner, there is a capability for moving backwards a limited number of lines. This is possible because lines which have been passed are not written to the destination immediately, but are held instead in an output queue whose maximum length depends on the amount of available store. Normally several hundred lines can be held in store at once.
If the destination is a disc file, or if the source file is sufficiently small that it can be held entirely in main store, it is possible to make more than one pass through the text.
ZED commands are available for moving parts of the source about (using in-store buffers), for outputting parts of the source to alternative destinations, and for inserting material from alternative sources."