EDSAC 2 OPERATING MEMORANDUM DECEMBER 1958. Safety of Users. The installation of the Decca Tape Unit will impose a considerable strain on the New Floor. Persons waiting to use the machine should avoid congregating in a group, and should spread themselves round the room, preferably horizontally. Mr. G. J. Stevens will advise on suit- able dispositions where necessary. The heavier Users are asked in the Public's interest to wait in the Tape Room: the operator in charge will call them by telephone when their turn arrives. (Sgd) E.N.MUTCH