Patent GB-1240611-A (GB)
Title: Device for automatically displaying the status of logic elements and changing their status
Inventor: LOOSCHEN FLOYD WILLIAM
IPC: G09G3/20
Filed: 1969-02-19
Abstract: 1,240,611. Indicating states of storage elements; computers. BURROUGHS CORP. 19 Feb., 1969 [21 Feb., 1968], No. 8953/69 Headings G4A and G4H. A display unit comprises a plurality of display lamps, one for each of a number of storage elements in a digital processing system, arranged in groups (or words) of eight, means for providing signals indicative of the status of the elements in a particular word and trigger elements responsive to the signals for switching on those lamps corresponding to set storage elements. As described, there are 64 columns of eight flip-flops in each of the units 17-20. Flip-flop data signals on lines 21 are applied to switching means 16 which couples a selected unit to the scan-out and scan-in matrices 11, 12. Change signals and address signals are also transmitted to the units over lines 22 and 23 for the purpose of changing any selected flip-flop. Scan-out matrix 11 is connected to switching means 16 by lines 24 receiving data signals from the selected unit and by lines 25 transmitting address signals to the unit. Scan-in matrix 12 sends data and address signals on leads 26, 27. An address register 13 is controlled by a counter to generate a series of addresses to address the 64 columns or words in succession, reading out the corresponding data via a register 14 to the display unit 30. This consists of a matrix of lamps 70, Figs. 3A, 3B, arranged in 64 columns of eight and each connected in series with a silicon controlled rectifier 71. The flip-flops in the selected unit are read-out on eight parallel leads 54-1, 54-8 by a signal on an appropriate address lead. The address signals are applied as a combination of markings on six leads to decode gates 76-1 to 76-64 (Fig. 3B). The gate giving an output energizes the corresponding column wire through lamp drive circuit 52. Those input leads 54-1 which are marked trigger the corresponding SCR 71 connected to the marked column wire. By this means the lamps are lit to indicate that the corresponding flip-flop is set. The display unit also comprises a matrix of push-button switches 40 arranged in 64 columns of eight so that any selected flip-flop can be set by pressing the corresponding button. A further button is pressed to cause the selected flip-flop to be reset instead of set. When a button is pressed a corresponding And gate 73 gives an output on one of the eight leads 61-1, 61-8 when that column is scanned by the address signals. Button 43 when pressed serves to reset all the flipflops in the first column word. Similarly, button 42 resets the second and third words. When a push-button 40 is pressed, an Or gate 74-1, 74-64 gives an output signifying that a button has been pressed in that column. These signals are applied to gates 75-1, 75-64 enabled in sequence by the address signals and sent out on lead 60 to control the transmission of the change signal to the appropriate flip-flop. Other gating arrangements are described for the address signals (Figs. 10 and 11, not shown).