Patent GB-1069528-A (GB)
Title: Data processing system
IPC: G06F13/12
Filed: 1964-12-17
Abstract: 1,069,528. Digital data processing. SPERRY RAND CORPORATION. Dec. 17, 1964 [Dec. 30, 1963], No. 51373/64. Heading G4A. A data processing system comprises a digital computer, various data handling devices and a controller for directing data flow between the computer and the data handling devices, the controller including: a memory for storing data and control words; a digital converter which converts an input thereto to digital form; and a comparator responsive to control words and the output of the digital converter for initiating data transfer. The system may be applied to road traffic control in a large city, the input variable to the digital converter being timed so that data transfer is initiated when a time predetermined by a control word has elapsed. The system described, Figs. 1a and 1b, comprises a digital computer 16; data handling devices 10-14 which may effect printing, storing or control functions; and a controller having a memory section 22, an address and priority section 34, an input section 68, and output control section 52. The computer communicates with the external data handling devices by means of request and acknowledge signals, a request signal being sent from an external device when it requires data from the computer, and an acknowledge signal being sent by the computer to the external device when the computer is ready to transmit the requested data thereto. In operation when an external device requires to transmit data to the computer, a request signal is applied to the priority network 41 which assuming that no higher priority device is issuing a request, responds to allow a controller memory address unique to the requesting device to be applied via a register 38 to the controller memory address register 40. At the same time (1) the data from the external device is gated via gates 70, 30, 32 to the drivers of the controller memory 24, which comprises magnetic cores and (2) a time tag from a digital converter 62 is appended to the data to be stored. In reading out a word from the controller to the computer, the control 66 presents a request signal to the priority network 41 which produces a signal to gate a controller memory address supplied by the computer via register 36 to the memory address register 40 thereby reading out a word via the memory data register 26 to a transfer register 72 whence the data is supplied to the computer over a cable 82. The results of a computation by the computer may be transmitted therefrom via the register 72 to the memory 24 for temporary storage. A signal from the external device is processed by the priority circuits as described above and causes a 100-bit word to be read out from the memory to the register 26. Group selection and translation circuits (Fig. 3a, not shown) are effective to route a 25-bit group as a control word to a control register 56. The control word identifies the external device and also contains a group of bits indicating when the data is to be transmitted, this group of bits being compared at 60 with the output of the digital converter 62 which consists of a counter to provide a signal for gating a 25- bit data group from a data register 54 at the desired instant of time.