A data-handling mechanics of on-line text editing system with efficient secondary storage access

The data-handling algorithm in many current editors 2 uses a text which is a continuous string of characters. In this technique the characters are moved directly from their input source to the text string by expanding it in tue core buffer. The disadvantage of such existing systems is due to the core buffer constraint. The buffer can be extended to the auxiliary storage but will result in less efficient auxiliary storage accessing. The data-handling algorithm presented here uses a text which consists of several substrings. Initially the text consists of only one substring which is the original version of the text. This text resides in the consecutive blocks of the scroll area of the tape; the characters carry smoothly across the blocks boundaries, producing a continuous string. No writing is permitted on this scroll area during the editing process. The characters which are inserted into the text for editorial changes are moved directly into a core buffer, producing new substrings. The substrings are logically interconnected in a linear fashion through a map. The map, in fact, contains pointers to all the substrings in the text.