Computer processing of biochemical information without going on-line.

an extensive central installation must be available with the ability to accept multiple inputs on a timesharing basis, one input terminal being located in the laboratory. Both these approaches are expensive. In the first case, the laboratory must bear the whole cost of the equipment and for practical reasons this may result in the provision of a computer too small adequately to do the rather complex tasks involved. On the other hand, although a large central computer may provide relatively cheap processing power, it is no small task so to design the central system that the laboratory can have unrestricted access at intervals of a few seconds throughout the working day, ie, whenever instrument readings must be recorded or the laboratory records are interrogated. It is likely, therefore, that off-line computers will continue to be used where the input data are collected in the laboratory and sent once or several times daily to a computer for batch processing. This does not even imply that the computer must be within physical reach of the laboratory, since a data link, eg, by telephone wire, may be possible. Of course batch processing laboratory results imposes certain limitations compared with an on-line connexion. These problems have been faced during the last two years in the biochemical laboratories of the Royal Postgraduate Medical School, during which time we have had access to a medium-sized general purpose digital computer. The purpose of this paper is to indicate the areas in which we have found the computer to be valuable and how the disadvantages of off-line working can be