| FARM ELECTRONICS LIMITED | Grantham | 1978 | Small company accounts |
| CONTRONICS LIMITED | Wallingford | 1978 | Audit-exempt subsidiary |
| GRATICULES OPTICS LIMITED | Cambridge | 1978 | Audit-exempt subsidiary |
| ACULAB LTD | Reading, Berkshire | 1978 | Group accounts |
| PP CONTROL & AUTOMATION LIMITED | Walsall | 1978 | Medium company accounts |
| WALKBURY ELECTRONICS LTD. | Peterborough | 1978 | Total exemption (full) |
| ELECTRO WIND LIMITED | Stoke-on-Trent | 1979 | Total exemption (full) |
| MEGACON CONTROLS LIMITED | Bath | 1979 | Total exemption (full) |
| THE KENTON GROUP LIMITED | Dartford | 1979 | Total exemption (full) |
| FLUKE PRECISION MEASUREMENT LIMITED | Norwich | 1979 | Full accounts |
| HALLMARK ELECTRONICS LIMITED | Newcastle under Lyme | 1979 | Total exemption (full) |
| MACKWELL ELECTRONICS LIMITED | Walsall | 1979 | Medium company accounts |
| TBA DONCASTER LIMITED | Doncaster | 1979 | Full accounts |
| MEREFIELD'S ELECTRONICS LIMITED | Kent | 1979 | Total exemption (full) |
| HAES TECHNOLOGIES LIMITED | Slough | 1979 | Total exemption (full) |
| STUART JAMES SYSTEMS LIMITED | Burton-on-Trent | 1979 | Total exemption (full) |
| GRANTHILL LIMITED | Farnham | 1979 | Total exemption (full) |
| TRENMEAD LIMITED | Wembley | 1979 | Unaudited abridged |
| COSTAIN INTEGRATED TECHNOLOGY SOLUTIONS LIMITED | London | 1979 | Audit-exempt subsidiary |
| KGS FIRE & SECURITY UK LIMITED | Edinburgh | 1979 | Full accounts |
| ELTIME LIMITED | Braintree | 1979 | Total exemption (full) |
| H. & B. SENSORS LIMITED | Bognor Regis | 1979 | Total exemption (full) |
| ZONAL RETAIL DATA SYSTEMS LIMITED | Edinburgh | 1979 | Group accounts |
| DOMO TACTICAL COMMUNICATIONS (DTC) LIMITED | Whiteley | 1979 | Full accounts |
| CTRONIX LIMITED | Cowbridge | 1979 | Total exemption (full) |
| DATATOTE (ENGLAND) LIMITED | Bristol | 1979 | Full accounts |
| ASHRIDGE ENGINEERING LIMITED | Holsworthy | 1979 | Small company accounts |
| ELECTROMECH DESIGN AND ASSEMBLY LIMITED | Leicestershire | 1980 | Total exemption (full) |
| PEKTRON PLC | Derby | 1980 | Group accounts |
| INTEGRATED DISPLAY SYSTEMS LIMITED | Newcastle upon Tyne | 1980 | Unaudited abridged |
| ENVIRONMENTAL MEASUREMENTS LIMITED | North Shields | 1980 | Total exemption (full) |
| SHIRE CONTROLS LIMITED | Gilston Nr Harlow | 1980 | Total exemption (full) |
| SYNATEL INSTRUMENTATION LIMITED | Nr. Cannock | 1980 | Small company accounts |
| T.W. ELECTRONICS (NEWBURY) LIMITED | Newbury | 1980 | Total exemption (full) |
| PRINTECH CIRCUIT LABORATORIES LIMITED | Chelmsford | 1980 | Total exemption (full) |
| BMS VISION LIMITED | Lancashire | 1980 | Small company accounts |
| DESIGN INITIATIVE LIMITED | Lewes | 1980 | Total exemption (full) |
| HAWKSLEY & SONS LIMITED | Hove | 1980 | Total exemption (full) |
| MAR EQUIPMENT LIMITED | London | 1980 | Total exemption (full) |
| MICROSS ELECTRONICS LIMITED | Ross-on-Wye | 1980 | Total exemption (full) |
| LOUDSPEAKER TECHNOLOGY LIMITED | Stroud | 1980 | Full accounts |
| PSION HOLDINGS LIMITED | Bourne End | 1980 | Full accounts |
| TELLERMATE LIMITED | Newport | 1980 | Full accounts |
| HEXAGON METROLOGY LIMITED | Telford | 1980 | Full accounts |
| MARLOW INTEGRATED DESIGNS LIMITED | Basildon | 1980 | Total exemption (full) |
| NO. 7 CONTACT LENS LABORATORY LIMITED | Fareham | 1980 | Full accounts |
| GORDON WILSON (PROCESS SYSTEMS) LIMITED | Hastings | 1980 | Medium company accounts |
| SCITEC INSTRUMENTS LIMITED | Trowbridge | 1980 | Total exemption (full) |
| QUANTUM PRODUCTION LIMITED | Okehampton | 1981 | Total exemption (full) |
| DENT INSTRUMENTATION LIMITED | Colne | 1981 | Total exemption (full) |
| MARRUTT LIMITED | Eastbourne | 1981 | Total exemption (full) |
| SPECIALIST ALARM SERVICES LIMITED | Newcastle upon Tyne | 1981 | Small company accounts |
| G. & B. ELECTRONIC DESIGNS LIMITED | Hampshire | 1981 | Total exemption (full) |
| KANE INTERNATIONAL LIMITED | Welwyn Garden City | 1981 | Full accounts |
| COMPUTIONICS LIMITED | Hilldale,parbold | 1981 | Medium company accounts |
| J J ELECTRONICS LIMITED | Bedford | 1981 | Total exemption (full) |
| ASTRATEC ELECTRONICS LIMITED | — | 1981 | Total exemption (full) |
| SCOTIA INSTRUMENTATION LIMITED | Aberdeen | 1981 | Full accounts |
| ARUN MICROELECTRONICS LIMITED | Littlehampton | 1981 | Total exemption (full) |
| EAGLE EYE LIMITED | Leyland | 1981 | Total exemption (full) |