Classifications

• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/14—Digital output to display device ; Cooperation and interconnection of the display device with other functional units
  • G06F3/153—Digital output to display device ; Cooperation and interconnection of the display device with other functional units using cathode-ray tubes
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G2360/00—Aspects of the architecture of display systems
  • G09G2360/04—Display device controller operating with a plurality of display units

Definitions

• This invention relates to data processing arrangements, and is particularly concerned with control units therefor.
• VDU Visual Display Unit
• VDU station In normal operation and for obvious reasons only one VDU station is written to at a time by the operator using a keyboard; the other VDU stations are most possibly being used as a reference for information input. Under these conditions and where, for example, the operator is controlling four VDU stations, the keyboards will spend 75% of their life unused.
• the invention also comprises a data processing arrangement provided with the control unit. ADVANTAGES OF THE INVENTION
• Figure 3 is a key to the complete diagram.
• a data processing arrangement 10 comprises four standard VDU stations 13, each provided with its own identification means 15, a single keyboard 11 dedicated to the stations 13, and a control unit 17 connectable to the VDU stations 13 by port connecting cables 18 and to the keyboard 11 by a port connecting cable 20.
• Each of the VDU stations 13 is provided with a data input (not shown) connected to the back of each station.
• the said circuitry which is in the form of a printed circuit board, is manually switchable, by operation of a standard scroll switch 19.
• the switch 19 is connectable to the control unit 17 by a cable 21 and is mounted on the keyboard 11, so as to be readily accessible to the keyboard operator. Depression of the VDU station selection switch 19 is, as explained below, confirmed by an audible signal and highlighted by functioning of the identification means 15 of the selected station 13 as well as by one of a group of four light emitting diodes (LED) 22 mounted on a control panel 17a. of the control unit 17.
• the panel 17a forms one end of the unit 17 and so is not fully visible in Figure 1.
• the panel 17a. also incorporates a key-operated security switch 24 for locking the keyboard 11 to a selected VDU station 13 for disabling keyboard data flow.
• the key of the switch 24 is removable.
• the group of four LEDs 22 is shown in Figure 2E.
• the group is provided with supply and return connections 26, 27 respectively. ( Figure 2F).
• the panel 17a carries two further LED's, namely 28, 29, also shovm in the right-hand side of Figure 2A.
• LED 28 is used to indicate when active sensing override (ASO) described below is in operation.
• LED 29 is used to indicate when power is being supplied to the control unit 17.
• the VDU station identification means 15 of this example comprise LED's connected to the control unit 17 by branches 18a. of the cables 1
• the control unit 17 is provided with an electrical power input cable 23 connectable to a ⁇ 8 volt supply.
• each of the VDU stations is for the presentation of different data.
• money exchang rates for example, money exchang rates, commodity values, company share values etc.
• IC 10 and IC 13 are connected to form a XOR/AND set-reset latch (shown in detail on the right-hand side of Figure 2Cr). This is set assuming that IC 11 remains in the 'up' mode.
• Pin 4 of IC 13 also goes high taking with it, pins 4 and 12 on IC 9, pin 6 on ICs 5 and 6. (A low frequency oscillator line marked 'LFO' is also taken high but will be described later). The action of pin 6 on ICs 5 and 6 going high inhibits the flow of data through the circuit.
• IC 11 is held low until the pulse ends. IC 11 switches on the rising edge of a pulse so that its counter is incremented (up) by one only when the logic on pin 15 goes high.
• the output address on pins 6 and 11 of IC 11 can now change.
• These two pins now contain in the form of a binary code the newly selected port address. This code is used to directly switch the routing within ICs 5 and 6 via pins 10 and 9 of the same.
• IC 7 takes this binary code on pins 2 and 3 and converts it into a sequential code. That is, one of the putput pins on IC 7 (pins 4, 5, 6, 7) are taken high.
• each of the terminals connected and switched on supplies power to the keyboard 11. They do this through individual line fuses, and diodes being combined on a common bus connected to the keyboard 11. This bus is also fused.
• each power bus is monitored by a combination of 1 mA current limiters and high sensitivity opto- isolators. Output from the isolators (IC 1, 2, 3, 4) is inverted by IC 8. The resulting logic levels are passed to IC 16 where a comparison is made with the newly selected address. If a terminal is connected, no change in the output state (high) of IC 16 occurs. However, if no terminal is connected at the selected address then the appropriate output pin (3, 4, 10 or 11) of IC 16 goes low.
• Additional circuitry around switch 30 causes first an audible signal 'beep' and secondly a light to come on if it is open circuit.
• the audible signal 'beep ' is provided by the tone generator 34 referred to above.
• Dedicated keycodes generated from the keyboard 11 may be used to initiate switching. This modification utilizes a keyboard keypress combination instead of a separate switch to change keyboard data routing, and could generate screen-displayed graphics to indicate screen selectio instead of the LED's 15.

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• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Human Computer Interaction (AREA)
• Physics & Mathematics (AREA)
• General Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Input From Keyboards Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10619912

Family Applications (1)

Country Status (3)

Family Cites Families (3)

• 1987
  • 1987-07-01 GB GB878715498A patent/GB8715498D0/en active Pending
• 1988
  • 1988-07-01 EP EP19880905934 patent/EP0338029A1/de not_active Withdrawn
  • 1988-07-01 WO PCT/GB1988/000513 patent/WO1989000314A1/en not_active Ceased

Non-Patent Citations (1)

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