GB1582381A

GB1582381A - Data entry apparatus

Info

Publication number: GB1582381A
Application number: GB2631477A
Authority: GB
Original assignee: Texas Instruments Ltd
Current assignee: Texas Instruments Ltd
Priority date: 1977-06-23
Filing date: 1977-06-23
Publication date: 1981-01-07
Also published as: DE2827714A1; JPS5412223A; FR2395551A1; FR2395551B1

Description

(54) IMPROVEMENTS RELATING TO DATA ENTRY APPARATUS (71) We, TEXAS INSTRUMENTS LIMITED, a British Company, of Manton Lane, Bedford; do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to data entry appa ratus and is particularly, but not exclusively, suited for use with teletext and viewdata type systems.

There have been many proposals for ex tending the uses to which domestic television recieving apparatus is put. In one of these, known as teletext, additional information is transmitted in binary coded form on one or more unused lines in each television field, the receiver including digital data storage means and a decoder for reproducing alphanumeric or graphical information on the television screen of the television picture. In viewdata systems the television receiver is used as a visual display unit of an elementary computer terminal, the receiver being connected via- the public telephone system to a computer at a remote point and the information derived from the computer is displayed in alphanumeric or graphical form on the screen of the receiver.

Domestic television receivers have also been used for games, teaching machine applications and for computing. All of these uses of a domestic television receiver require some kind of keyboard for entering information to indicate, for example, further information to be displayed or a response to a question'displayed on the screen. Where a simple numeric entry only is required a keyboard of the kind provided for a pocket electronic calculator could be used. However, if a fullalpha- numeric keyboard is required for entry of the information the keyboard would obviously be very much more expensive.

It is an object of the present invention to provide an inexpensive data entry apparatus for use in conjunction with a data display means.

According to the present invention there is provided data entry apparatus including means'for generating in sequence, cyclically, a plurality of signals respectively representing a plurality of data symbols to be entered; means for producing in sequence, cyclically and synchronously with the generation of signals, individual visible displays of the data symbols at a substantially fixed location on a display means, a single manually operable switch, and data storage means connected to receive and store selectively under the control of the switch only those signals representing a data symbol generated and displayed at the time of an operation of the switch, whereby an operator on seing a data symbol displayed can cause signals representative of that data symbols to be stored in the data storage means by operation of the switch.

The signals representing the data symbols may be numbers, e.g. n-bit binary coded numbers, and these may be generated in ascending or descending order or alternately in ascending order to a maximum and then in descending order to a minimum. The visible displays may be produced on a television -dis- play screen by video signals generated in res ponse tb the n-bit binary numbers representing the symbols by means of a read only memory (ROM). The n-bit binary numbers may itself be the video signal to be -applied tci the means for producing a visible display e.g: a cathode ray tube. Alternatively it could bè treated as coding that is translated by means of a character generator ROM into various display patterns e.g. 7-bit alphanumerid ASCII coding. A further alternative is that the n-bit binary number may be arbitrary but applied to another ROM can be converted to an ASCII or other coding which can then be interpreted in the normal manner by the character generator ROM to produce a display.

The rate at which the sequence of signals and visible displays are worked through may be variable. For example, an operator may bd provided with a key which when pressed causes the symbols to be stepped at i second intervals and when released allows the symbol bols to be stepped at one second intervals.

Alternatively, a continuously variable 'sequencing speed may be provided by à manually operated potentiometer or other suitable apparatus. A facility may be provided for reversing the direction of sequencing, for example, by a forward-reverse switch, or by an automatic change of sequencing direction every time the sequencing switch is operated or the signals may be stepped forward at i second intervals when the key is pressed and stepped backwards at one second intervals on its release.

A key may be provided having a one-shot action, that is to say the symbol displayed may be stepped on one at a time in response to each depression of the key.

In order that the invention may be fully understood and readily carried into effect it will now be described with reference to the accompanying drawing, of which: Figure 1 shows an example of data entry apparatus according to the invention; and Figure 2 shows a circuit diagram of the apparatus of Figure 1.

In Figure 1 there is shown a video display means such as, for example, a domestic television receiver indicated by the reference 1.

Switch means 2 is connected to the receiver 1 by means of a cable 3. The switch means 2 has a first key 4 and a second key 5, the functions of which will be described later. Apparatus within the receiver 1 causes the production of alphanumeric symbols one at a time at the top left-hand corner of the screen; the letter T is indicated by the reference 6 and represents the symbol being displayed at the time. The apparatus also includes storage means for recording selected symbols and may be arranged to display those selected at the time.

By way of example the letters CAT are shown at 7 displayed beneath the letter T in the top left-hand corner of the screen. As the symbols are displayed cyclically, when the operator sees one which he wishes to enter he presses the key 4 which causes that symbol to be entered in the next vacant position in the storage means provided. The key 5 enables variation of the rate at which the symbols are changed at the top left-hand corner of the screen; when the key 5 is pressed the rate is increased, for example, by factor of four.

If a single symbol only is to be entered, the display of the selected symbols can be omitted without risk of the operator losing track of his position. If several symbols are to be inserted at a time the operation of the key 4 providing selection rather than entry of the symbols, either a data entry symbol may be provided so that operation of the key 4 when this symbol is displayed results in the entry of the signals representing the symbols so far selected, or a further key, not shown in Figure 1, may be provided for effecting data entry of the signals selected.

Figure 2 shows in block diagrammatic form circuitry which may be included within the receiver 1 for enabling data entry by means of the switch means 2. Clock pulses from a clock 10 in Figure 2 are applied directly through a NAND gate 11 to the input of a counter 12 and after division in frequency by four in the frequency divider 13 via a NAND gate 14 to the input of the counter 12. The gates 11 and 14 are controlled by an input on a terminal 15, so that when the input is high the gate 14 passes signals and when the input is low the gate 11 passes signals because of the inversion in an inverter 16 of the signal on the terminal 15, which is applied to an input of the gate 11.

The number accumulated in the counter 12 is fed out in parallel over channel 17 via a gate 18 to inputs of a read only memory 19, and also via a gate 20 to the inputs of a buffer store 21. The store 21 has a capacity for storing several numbers which are stored and read out in sequence. The outputs of the memory 19 appear in parallel and are converted to serial form in a unit 22, for example a shifting register, and are applied as video signals via a conductor 23 to the control electrode of a cathode-ray tube 24. The electron beam of the CRT 24 is caused to scan a television type raster by means of scanning circuits 25 controlled by timing circuits 26 which also have other functions to be described later. The data stored in the buffer store 21 can be entered in a random access memory 28 via a multiple gate 27, the memory 28 having an address circuit 29. Output signals from the memory 28 are applied via a channel 30 to the inputs of the memory 19.

The gate 20 is controlled by signals applied to a terminal 31 which is also connected to select sequential locations in the store 21.

The signals in the store 21 are also applied to an output circuit 32, the details of which will depend on the particular application of the apparatus and will not be described further, from which output signals appear at a ter minal 33. Other data to be displayed on the cathode-ray tube screen can be applied via a terminal 36, which is connected to the memory 28 and from which stored signals can be applied to the memory 19 to produce the required display.

When data is to be transferred from the buffer store 21 into the random access store 28, a signal is applied to a terminal 34 for effecting the data entry; this signal could, for example, be produced by the operation of the key 4 (Figure 1) when a particular symbol is displayed and therefore the counter 12 stores a particular number. Since the address cir cuits 29 of the RAM 28 are controlled by the timing circuits 26, the operation of the gate 27 to effect entry to a particular address must also be controlled by the circuits 26, and for this reason a gate 35 is provided, controlled by the timing circuits 26, to connect the ter minal 34 to the gate 27.

The numbers stored in the buffer store 21 are also applied to the input of the ROM 19 via a gate 37, which is controlled by an output of a character counter 38 controlled by the timing circuits 26. The counter 38 follows the scanning of a line of the raster on the cathoderay tube 24 to control the store 21, the gate 37 and the ROM 19 so that the symbols represented by the numbers stored in the store 21 are displayed in a row on the screen of the CRT 24 in the same way as the letters CAT shown at 7 on Figure 1. A conductor 39 is connected to the counter 38 to apply it to a signal each time there is an input on the terminal 31, so that the counter 38 can record the number of symbols to be displayed, as each input on the terminal 31 indicates that another symbol has been selected.

A column counter 40 is provided for selecting the successive rows of signal elements from the ROM 19 as the symbols are described; it will be understood that each symbol consists of signal elements in a number of adjacent lines of the raster scanned on the screen of the CRT 24 so that the symbol is produced as a matrix of dots. The counter 40 is controlled by the timing circuits 26.

The buffer store 21 has a plurality of locations, each capable of storing a number, and the contents of the locations are applied successively via the gate 37 to the input of the ROM 19 under the control of the timing circuits 26, so that the symbols represented by the numbers appear as shown at 7 in Figure 1. The character counter 38 records how many numbers are stored in the buffer store 21 by counting the signals applied to the terminal 31 as a result of the actuation of the switch 4. The gate 37 is opened to pass the numbers one at a time from the buffer 21 to the ROM 19.

When the numbers representing the whole of a group of symbols are stored in the buffer store 21 and consequently the group of symbols is displayed on the screen of the CRT 24, entry of the numbers into the RAM 28 is effected by the application of a signal to the terminal 34 which causes the gate 27 to be opened at a time or a sequence of times determined by the timing circuits 26. The character counter 38 may be arranged to ensure that the number of entries from the buffer store 21 into the RAM 28 is equal to the number of locations of the store 21 which are storing a number, so that unnecessary transfers from empty locations are avoided.

In the operation of the circuit shown in Figure 2, the total in the counter 12 increases from zero to a maximum value and is then automatically reset to zero when the counting is resumed. The pulses from the clock 10 may, for example, occur at 4 hz so that the total in the counter 12 is stepped four times a seond whilst the clock pulses are fed to it through the gate 11. If, however, as a result of the signal on the terminal 15 the gate 14 is enabled to pass signals instead of the gate 11, the output of the clock 10 is slowed to 1 Hz so that the total in the counter 12 is incremented once per second. The timing circuits 26 transfer the total from the counter 12 to the inputs of the ROM 19 via the gate 18, so that a symbol corresponding to the number in the counter 12 is generated in the top left-hand corner of the screen of the cathode-ray tube 24, at 6 shown in Figure 1. As shown the counter 12 has seven output conductors and the memory 19 seven input conductors. This means that up to 27 different symbols can be displayed on the screen of the tube 24. These symbols may include the ten decimal digits, the 26 letters of the alphabet, punctuation marks, mathematical symbols and symbols having a special significance for the system chosen arbitrarily, for example. When an operator viewing the cathode-ray tube 24 sees a displayed symbol he wishes to enter into the RAM 28, he presses the key 4 (Figure 1) which causes a signal to be applied to the terminal 31 opening the gate 20. When the gate 20 is open the total in the counter 12 at the time is recorded in a first vacant location of the buffer store 21 and can, if desired, be applied directly to the output circuit 32.

The number in the counter 12 needs to be latched so that it can be applied to the character generator ROM 19 for continuous display until the chosen character is chosen.

In this method, two separate screen addresses are involved. The menu location occupied by 6 (Figure 1) and the final entry location represented by 7 (Figure 1). The menu location is fixed and hence can be hard-wired, but once the character for entry in location 7 has been selected then the binary number being generated by counter 12 (Figure 2) must be entered into the buffer store 21. The character counter 38 is used to control the reading of the numbers stored in the buffer store 21 and their application to the ROM 19 to cause the display at location 7 of the characters selected and the numerical representations of which are stored in the buffer store 21. The character counter 38 includes in addition to a counter the gating arrangements needed to produce the output signals as described above.

This same counter can be used to display a visible symbol or cursor to indicate the next character space location 7 where the next selected character will appear.

The counter 12 may be made reversible and, if desired, a separate control may be provided for reversing the direction of counting, so that if an operator wishes to enter a symbol which has just passed he can count backwards until he reaches it.

The entry of a multiple symbol group could be effected by means of a separate key as explained above. Alternatively, one of the symbols displayed on the cathode-ray tube screen may be used to enable data entry so that if the operator presses the key 4 when this particular data entry symbol is displayed, the corresponding number on being gated from the counter 12 would cause transfer of the numbers stored in the buffer store 21 to the RAM 28.

In a simple system selection and entry of a symbol could be effected at the same time by operation of the key 4, in which case the buffer store 21 could be used merely to enable the provision of a display of the selected and entered symbols.

If desired, the rate of the clock 10 may be made variable' over a range of, for example, 25 pulses'per second to 1 pulse per second, and the switch unit 2 may be provided with a joy-stick or other similar control for regulating the clock rate. Alternatively, a switch of which each actuation steps the counter 12 on one may be provided in which case the clock 10 and its associated components 11, 13, 14, 15 and 16 would not be'required.

WHAT WE CLAIM IS: 1. 1. Data entry apparatus including means for generating in sequence, cyclically, a plurality of signals respectively representing a plurality of data symbols to be entered, means for producing in sequence, cyclically and synchronously with the generation of signals, individual visible displays of the data symbols at a substantially fixed location on a display means, a single manually operable switch; and data storage means connected to receive and store selectively under the control df the switch only those signals- representing a data symbol generated and displayed at the time of an operation of the switch, whereby an operator on seeing a data symbol display ed can cause signals representative of that data symbols to be stored in the data storage means by operation of the switch.

2. Apparatus according to claim 1 wherein the means for producing visible displays is connected to he responsive to signals stored in the data storage means to produce a display of data symbols represented by the signals stored in the'data storage means at another location of the display means, means being provided for controllably enabling the entry into further data storage means of the signals stored in the first-mentioned data storage means.

3. Apparatus according to claim 2 wherein the means for controllably enabling the entry of the signals into the further data storage means includes a second manually operable switch in response to the operation of which the entry is effected.

4. Apparatus according to claim 2 wherein the means for controllably enabling the entry of the signals into the further data storage means includes means responsive to the operation of the manually operable switch when signals representing a particular data symbol are generated to produce a signal for effecting the entry of the signals into the further data storage means.

5. Apparatus according to any preceding claim wherein the means for generating signals includes an n-bit binary counter to which in operation pulses are applied to increment progressively the total in the counter, the signals representing the binary digits of the total.

6; Apparatus according to claim 5 including manually operable means for applying a pulse to the counter in response to each operation of the means.

7. Apparatus according to claim 5 including clock pulse generating means connected to apply pulses to the counter.

8. Apparatus according to claim 7 including controllable means for adjusting the repetition frequency of the (clock) pulses generated by the clock pulse generating means.

9. Apparatus according to any of claims 5 to 8 including means for converting the signals derived from the counter into ASCII alphanumeric codings for the corresponding data symbols, which codings form the signals which - are applied to and stored in the data storage means.

10. Apparatus according to anypreceding claim wherein the means for producing visible displays of the items of data includes a read only memory in which addresses are selected by the signals generated by the signal generating means and produces output pulses representing in dot matrix form the data symbols corresponding to the signals applied as addresses to the memory.

11. Apparatus according to claim 10 wherein the means for producing visible -dis- plays includes as the display means a cathoderay tube and means for producing a raster scan on the screen of the tube, the tube being connected to receive the output pulses from the read only memory to produce the visible displays of the data symbols.

12. Data entry apparatus substantially as herein described with reference to the accompanying drawings. ~~ ~~

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

data entry symbol is displayed, the corresponding number on being gated from the counter 12 would cause transfer of the numbers stored in the buffer store 21 to the RAM 28.

In a simple system selection and entry of a symbol could be effected at the same time by operation of the key 4, in which case the buffer store 21 could be used merely to enable the provision of a display of the selected and entered symbols.

If desired, the rate of the clock 10 may be made variable' over a range of, for example, 25 pulses'per second to 1 pulse per second, and the switch unit 2 may be provided with a joy-stick or other similar control for regulating the clock rate. Alternatively, a switch of which each actuation steps the counter 12 on one may be provided in which case the clock 10 and its associated components 11, 13, 14, 15 and 16 would not be'required.

WHAT WE CLAIM IS: 1. 1. Data entry apparatus including means for generating in sequence, cyclically, a plurality of signals respectively representing a plurality of data symbols to be entered, means for producing in sequence, cyclically and synchronously with the generation of signals, individual visible displays of the data symbols at a substantially fixed location on a display means, a single manually operable switch; and data storage means connected to receive and store selectively under the control df the switch only those signals- representing a data symbol generated and displayed at the time of an operation of the switch, whereby an operator on seeing a data symbol display ed can cause signals representative of that data symbols to be stored in the data storage means by operation of the switch.
2. Apparatus according to claim 1 wherein the means for producing visible displays is connected to he responsive to signals stored in the data storage means to produce a display of data symbols represented by the signals stored in the'data storage means at another location of the display means, means being provided for controllably enabling the entry into further data storage means of the signals stored in the first-mentioned data storage means.
3. Apparatus according to claim 2 wherein the means for controllably enabling the entry of the signals into the further data storage means includes a second manually operable switch in response to the operation of which the entry is effected.
4. Apparatus according to claim 2 wherein the means for controllably enabling the entry of the signals into the further data storage means includes means responsive to the operation of the manually operable switch when signals representing a particular data symbol are generated to produce a signal for effecting the entry of the signals into the further data storage means.
5. Apparatus according to any preceding claim wherein the means for generating signals includes an n-bit binary counter to which in operation pulses are applied to increment progressively the total in the counter, the signals representing the binary digits of the total.
6; Apparatus according to claim 5 including manually operable means for applying a pulse to the counter in response to each operation of the means.
7. Apparatus according to claim 5 including clock pulse generating means connected to apply pulses to the counter.
8. Apparatus according to claim 7 including controllable means for adjusting the repetition frequency of the (clock) pulses generated by the clock pulse generating means.
9. Apparatus according to any of claims 5 to 8 including means for converting the signals derived from the counter into ASCII alphanumeric codings for the corresponding data symbols, which codings form the signals which - are applied to and stored in the data storage means.
10. Apparatus according to anypreceding claim wherein the means for producing visible displays of the items of data includes a read only memory in which addresses are selected by the signals generated by the signal generating means and produces output pulses representing in dot matrix form the data symbols corresponding to the signals applied as addresses to the memory.
11. Apparatus according to claim 10 wherein the means for producing visible -dis- plays includes as the display means a cathoderay tube and means for producing a raster scan on the screen of the tube, the tube being connected to receive the output pulses from the read only memory to produce the visible displays of the data symbols.
12. Data entry apparatus substantially as herein described with reference to the accompanying drawings. ~~ ~~