(19)

(11)

EP 0 433 433 A1

(12)

(43) Date of publication: 26.06.1991 Bulletin 1991/26 (21) Application number: 90910820.0 (22) Date of filing: 31.07.1990

(51) International Patent Classification (IPC):  G06F 9/ 44( . ) (86) International application number: PCT/GB1990/001190 (87) International publication number: WO 1991/002307 (21.02.1991 Gazette 1991/05)

(84) Designated Contracting States: DE FR GB (30) Priority: 31.07.1989 GB 19890017490 (71) Applicant: Hewlett-Packard Company Palo Alto, California 94304 (US)	(72) Inventors: DUGGAN, Hugh Hewlett Packard Limited Stoke Gifford Bristol BS12 6QZ (GB) MOREL, William Redmond W.A. 98052 (US) (74) Representative: Smith, Denise Mary  Hewlett-Packard Limited Cain Road Bracknell, Berkshire RG12 1HN Bracknell, Berkshire RG12 1HN (GB)