CD-ROM technology has tremendous potential for storing and enabling access to just the type of data contained in national bibliographies. A single CD-ROM can hold the equivalent of c.250,000 A4 sheets of print. CD-ROMs are easily replicable, and therefore offer security as well as enabling the information contained to be made more widely available. Of the two methods used to convert print to binary data in electronic form, scanning and keying, databases published by Chadwyck-Healey use the latter. In the case of national bibliographies on CD-ROM, new records are created electronically at the very first stage of cataloguing, while older records are converted by keying. Chadwyck-Healey has developed an extensive CD-ROM list, focusing on both bibliographic and full-text literary works. The national bibliographies it produces on CD-ROM are those of the UK, France, Germany, Italy, Portugal and Spain. That of the Netherlands is shortly to appear. Bibliographic coverage is further extended by several other databases produced by Chadwyck-Healey. National bibliographies on CD-ROM produced by other bodies are those of Finland, Norway, Bulgaria, Singapore and the USA. Although other means of making this sort of material are now competing with CD-ROM, it looks like holding its own for some time.
