This paper offers a brief survey of some important developments in the use of compute~rs in making dictionaries and lexicons. Making a dictionary revolves collecting the data, sorting and lemraatizing, editing and printing. Five major types of machine-readable dicti0par~e~ have d~veloped from these procedu(es: Machine Readable Lexicons of individual authors, Machine Readable Dictionaries with codes for linguistic information, Machine Dictionaries with selected information, and Lexical Databases with lexi~91 information abstracted from machine-readable dictionaries. The second edition of the OED is a machine-readable dictionary with codes that may provide the basis for a diachronic lexical database.In his article on "~ictionaries pf the t~l~ext Cent tury," Richard Bailey (,1986) remincl~ us that thg first use of computers in ~ humani~ began more than forty years ago now, '~hen Thomas J. Watson, 8r, pro~de~ assistan~g to F~r Roberto Busa in his attempt to repare ~ word i~aO~x to the works of St Thomas Aquinas, ,a word iodex that could be used to prepare a dicfi0naE1 of his distinctive philosophica t .an=d ~eolog~cal ~sage '' (p. Harry M. Logan, associate professor ~f English, has written The Dialect of the Middle English Life of St. Katherine (Mouton, 1973), using th e gomputer in a study of medieval dialectology. He has also written articles on computational stylistics and literary analysis in CHum, Language and Style, College Literature, and on the dictionary in Dictionaries. Computers and the Humanities 25: 35!--361, ~t99~. © 1991 Kluwer Academic Publisher~. Printe d in the Netherlands.125). Since then, electronic lexicography has been a rapidly developing field, and these developments have been well reflected in the pages of Chum, which in its first twenty-five years has published some twenty-five articles on electronic lexicography. A recent issue (24, 5/6, 1990, 337--530) was given over almost entirely to uses of the computer in Italian lexicography.The first volume of CHum, in 1966, contained an account by the lexicographer Laurence Urdang of one of the earliest uses of computer editing in a commercial dictionary. In 1959, Urdang, who was then the associate editor of the Random House Dictionary, designed a database system for encoding the separate elements of the dictionary to allow the computer tO do the sorting, codifying, arranging: and checking the data at hand and the text to be Written. He broke down the information in the dictionary into seven categories: illustrations, main e~nes (incl~l~g pronunciation, inflected forms, parts of sp~,ech), definitions, variants, etymologies, run-on entries (words not defined because of transparency), and additional information like synonym studies, lists usage notes, etc. Dividing th e definitions into 158 subject fields, like physics, chemistry, or fine arts, allowed the extraction of subject labels so that specialists could review the cqpy. The American College Dictionary was used as ,a base and codified. Over 130,000 entries were ~en punched into standard 80-colu...