| 摘要 |
705,482. Digital electric calculating-apparatus. NATIONAL RESEARCH DEVELOPMENT CORPORATION. May 19, 1950 [July 7, 1949], No. 15187/49. Class 106 (1). [Also in Group XL(c)] A digital computer including an electrostatic storage device comprising an insulator arranged to be scanned by an electron beam to set up at discrete areas on the insulator charge distributions representative of information to be stored, the scanning action being such that pauses occur during which the beam is held stationary, is characterized by the provision of means for switching off the electron beam for part of each pause. After reading a digit (i.e. either a "dot = 0" or a " dash = 1 ") recorded on a CRT memory tube, a finite time elapses before the digit to be recorded in the same data position is determined by the computer, and since it is undesirable to keep the electron beam on the one spot longer than (say) two microseconds, a so-called "meditation pulse is arranged to switch off the beam for a predetermined period. Negative-going " dot " pulses from a suitable generator are applied continuously via a diode D16 to cut off a valve V13, causing positive pulses, limited to a peak of 50 volts by the action of a diode D17, to be passed to a cathode follower V14 supplying the grid of the memory tube. Meditation pulses, coming down to 20 volts, are passed through the diode D17 shortly afterwards, causing the CRT beam to be cut off. Other arrangements for applying the meditation pulses are described, and the following Specifications are referred to:- 645,691, 657,591, 682,156 and 705,474. |
