GB863634A - Improvements relating to data storage arrangements, especially for digital computers - Google Patents

Abstract

863,634. Electric digital-data-storage apparatus. ELECTRIC & MUSICAL INDUSTRIES Ltd. March 27, 1957 [April 7, 1956], No. 10673/56. Class 106 (1). A data-storage arrangement comprises a circulating store with an input and output path including a normally closed gate, a control signal generator and means for opening the gate at a predetermined time in response to a control signal from the generator to allow the recording in or reproduction from the store of an information signal, the generator being responsive to each opening of the gate to alter the timing of succeeding control signals. The invention may be applied to a magnetic drum storage system operating as described in Specification 863,635. This includes a constant-speed drum 1 which can accommodate sixty-four, six-binary-coded decimal-digit words on each circumferential track. As described in the above-mentioned Specification as each new word is stored, all the existing words are shifted in a clockwise direction to make room for it. An output pulse Pe from a cycle counter 15, 16 occurs when the first digit of the stored information is passing under the reading-head 9. Output signals from the reading-head passing via a gate 40, are normally prevented by an " inhibit print " potential on line 33, but when this potential is removed the next Pe pulse sets a trigger circuit 35 via gate 30 and the latter allows the same Pe pulse through a gate 36. This opens a gate 37 to allow a clock pulse Co to set a trigger circuit 39 which, in turn, opens a gate 40, allowing digit signals from the reading head 9 to pass through on line 32 to a printer or other output means. The output signal from the gate 36 is also fed back via a delay element 41 to inhibit a gate 42 and so prevent the next clock pulse Co from reaching the counter 15, 16. Accordingly, the next output pulse Pe from the counter will occur one digit time later and, during the next cycle, the second digit will be passed through the gate 40 to the printer and so on. When the last word has been read out the pulse Pe occurs during the period of a pulse Wo initiated by a datum signal on the drum. This inhibits the gate 30 and passes a signal through a gate 31 which has the same effect as the " inhibit print " potential. It is stated that the system could be adapted for entering data into the drum store, in which case the system described in Specification 863,635 could be adapted for reading out. Specifications 707,634 and 827,582 also are referred to.