Contents:
- Cable & Wireless
- Cakebread
- Calcomp
- Calcutronics
- Calomax (Engineers) Ltd
- Cambion
- Cambridge Instruments
- Cardkey Ltd
- CarterParratt Group
- CAS Text Processing Systems
- CASE (see Computer & Systems Eng.)
- Cave & Tab
- CBM Business Machines Ltd
- CEAG
- CEIR Inc.
- Celdis Ltd
- Centronics Data Computer (UK) Ltd
- Cescom Electronics Ltd
- Cetec Systems Ltd
- Cetronic Ltd
- Channel Electronics (Sussex) Ltd
- Cherry Electrical Products Corp
- Chessell Ltd
- Chloride Alcad Ltd
- Chloride Granley
- Chloride Transipack
- Cifer Systems Ltd