CA1195787A - Process for the representation of control symbols on a screen of a display device - Google Patents
Process for the representation of control symbols on a screen of a display deviceInfo
- Publication number
- CA1195787A CA1195787A CA000395750A CA395750A CA1195787A CA 1195787 A CA1195787 A CA 1195787A CA 000395750 A CA000395750 A CA 000395750A CA 395750 A CA395750 A CA 395750A CA 1195787 A CA1195787 A CA 1195787A
- Authority
- CA
- Canada
- Prior art keywords
- screen
- symbols
- control
- representation
- assigned
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G1/00—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F40/00—Handling natural language data
- G06F40/10—Text processing
- G06F40/103—Formatting, i.e. changing of presentation of documents
- G06F40/117—Tagging; Marking up; Designating a block; Setting of attributes
Abstract
ABSTRACT OF THE DISCLOSURE
A PROCESS FOR THE REPRESENTATION OF CONTROL SYMBOLS
ON A SCREEN OF A DISPLAY DEVICE
A process and an arrangement for the representation of control symbols which determine the properties of alpha-numeric and/or graphic characters which can be represented on a screen (BS) of a display unit (AE). Code words assigned to the control symbols are stored in a page store (SP) in addition to code words assigned to the characters to be represented. In order to be able to modify the control symbols, these are indicated by arranging that, following the actuation of a switch which is assigned to the control symbols and is arranged on a keyboard (TA), special symbols which characterise the control symbols in question are represented at all those positions of the screen (BS) which are assigned to a control symbol. A switching stage (S) supplies a signal (S1) by means of the keyboard (TA) during the represen-tation of those points on the screen (BS) assigned to the control symbols and which supplies during the read-out from the page store (SP) of a code word (CW) assigned to a control symbol a signal (S2) to an image control unit (BST) which triggers the representation of the special symbol on the screen (BS).
A PROCESS FOR THE REPRESENTATION OF CONTROL SYMBOLS
ON A SCREEN OF A DISPLAY DEVICE
A process and an arrangement for the representation of control symbols which determine the properties of alpha-numeric and/or graphic characters which can be represented on a screen (BS) of a display unit (AE). Code words assigned to the control symbols are stored in a page store (SP) in addition to code words assigned to the characters to be represented. In order to be able to modify the control symbols, these are indicated by arranging that, following the actuation of a switch which is assigned to the control symbols and is arranged on a keyboard (TA), special symbols which characterise the control symbols in question are represented at all those positions of the screen (BS) which are assigned to a control symbol. A switching stage (S) supplies a signal (S1) by means of the keyboard (TA) during the represen-tation of those points on the screen (BS) assigned to the control symbols and which supplies during the read-out from the page store (SP) of a code word (CW) assigned to a control symbol a signal (S2) to an image control unit (BST) which triggers the representation of the special symbol on the screen (BS).
Description
The invention relates to a process for the xepresent-ation of cont~ol symbols on a scxeen of a display device which contains a page store which can store code words assigned to alphanumeric and/or graphic characters to ~e displayed on the 5 screen and control symbols which determine properties of the characters, a keyboard being provided by which the code words assigned to the characters and the control symbols can be input into the page store, and an image control unit together with a character generator which controls the representation of the characters on the screen.
With the telecommunications service "tele-screen text"
(Video-tex-Interactive), it is possible to call up data stored in a central unit via a telephone line for display on a television set. The items of data are represented on the screen of the television set which serves as a display device. It is possible to represent alphanumeric characters and/or patterns composed of graphic characters.
Presenters of information have available to them editing devices by means of which the items of data are prepared in the form of screen contents. The screen contents are then transmitted to the central unit, whereupon they can be called up by subscribers.
One screen content is referred to as one page. For example, a page may contain 960 character arrays which are ~5 arranged in 24 rows each comprising 40 character arrays. In the case of the representation of alphanumeric characters, one character is represented in each character array. The character array ma~ consist, for example, of 8x10 or 8x12 image points, by
With the telecommunications service "tele-screen text"
(Video-tex-Interactive), it is possible to call up data stored in a central unit via a telephone line for display on a television set. The items of data are represented on the screen of the television set which serves as a display device. It is possible to represent alphanumeric characters and/or patterns composed of graphic characters.
Presenters of information have available to them editing devices by means of which the items of data are prepared in the form of screen contents. The screen contents are then transmitted to the central unit, whereupon they can be called up by subscribers.
One screen content is referred to as one page. For example, a page may contain 960 character arrays which are ~5 arranged in 24 rows each comprising 40 character arrays. In the case of the representation of alphanumeric characters, one character is represented in each character array. The character array ma~ consist, for example, of 8x10 or 8x12 image points, by
-2- ~
~s~
which the individual characte~s are represented. Graphic patterns are represented hy ~es~ectiye characte~ ~rXays each containing one graphic character co~posed of 2x3 graphic Ple~ents. The graphic patterns are composed from the combinations of light and dark graphic elements in the various colours, and it is not possible to change the colours within one character array.
The display device contains an image control unit which controls the representation of the characters on the screen.
The image control unit contains a character gene.rator which stores a predetermined supply of alphanumeric and graphic characters. With the use of code words which are stored in a page store and which represent the addresses of the character generator, data words assigned to the image points of the characters or to the graphic elements are read out from the character generators and fed to a display unit which contains the screen.
The properties of the characters which can be represented are determined by control symbols, which are likewise stored in the form of code words in the page store. The control symbols indicate, for example, in which colour the characters are to be represented, whether the characters are to be represented in a flashing or non-flashing manner, and whether at normal height or at double height. In the case of serial coding of the characters and of the control symbols, each position on the screen is assigned one zone of the page store provided for a code word. If a storage zone contains a code word of a control symbol, generally no character is represented at the corresponding position on the screen. A manner of assignment of code words to ~3~
~35~
characters and to control symbols is described in respect o serial coding, for ex~mple, in the magazine 'IFunkschau'' (1977), Vol. 18l pages 78-82.
In the case of parallel coding, ~he number of the binary characters of the code words assigned to the characters which can be represented is increased, so that each character can be accompanied by a control symbol forming accompanying information. In this case the gaps provided for the control ~ symbols are omitted, and characters can be represented anywhere on the screen. It is also possible to combine parallel coding with serial coding.
As the control symbols are not displayed in the normal page content, and therefore in the case of serial coding are indistinguishable from an "interspace" symbol on the screen, if the screen content must be sat up or amended it is not readily possible to recognise the positions of any control symbols which have already been stored~
It would be conceivable, following the actuation of a corresponding key on a keyboard provided for the setting up or processing of the screen content, to display a special symbol, for example the write mark, at every position at which a control symbol is stored. If a plurality of control symbols are stored consecutively, again it is impossible to recognise the position of a specific control symbol, for example, so that only that control symbol is amended.
It is also already known to display a text which characterises a control symbol in an additional display row at the lower edge of the screen whenever the write mark is ~4-~9S~
positioned on the screen at a position to which a control symbol is assigned. In this way it is possible to recognise the position of a control symbol which is to be modified. However, if the control symbol is firstly operative at another position, 5 it is firstly necessary to find this control symbol by means of the write mark. Furthermore, a relatively high circuitry outlay is needed, since the additional display row must be represented on the screen.
One object of the present invention is to provide a process whereby it is possible to determine that point of the screen of a display device which is assigned to a speciiic control symbol in a simple and Very rapid fashion.
The invention consists in a process for the xepresentation of control symbols on a screen of a display device which contains a page s~ore which can store code words which are assigned to alphanumeric and/or graphic characters to be displayed on the screen and control symbols which determine properties of these characters, a keyboard being provided by means of which the code words assigned to the characters and control symbols can be input into the page store, and an image control unit being provided together with a character generatcr which controls the representation of the characters on the screen, said process being such that actuation of a keyboard switch assigned to control symbols causes special symbols which characterise the control symbols in question to be represenced at all relevant positions on the screen assigned to a control symbol in the page store.
The process proposed in accordance with the invention 1~9S~37 has the advantage that the setting up, correction and up-dating of a screen content can be carried out simply and Yexy rapidly, since it is possible to directly display those positions of the screen which are assigned to the individual control symbols.
In order to achieve a clearly defined assignment of any represented characters to the related control symbols, it is advantageous to represent the alphanumeric and/or graphic characters during the representation of the special symbols.
Under certain circumstances it can also be advantageous to block the representation of the alphanumeric and/or graphic characters during the representation of the special symbols.
In order to be able to indicate on the screen the function of the control symbol to the user, it is advantageous for the representation of the special symbols on the screen to be accompanied simultaneously by a representation of texts characterising the corresponding control symbols, in an additional display row. For example, simult~neously to the representation of the special symbol "Bl", by way of text the word "flashing"
; is displayed in the additional display row.
A further character generator~ or an elaboration of the character generator already provided, is unnecessary if the special symbols consist of characters which are stored in the character gen~rator and which are represented in a special manner. It is expedient to use as special SymbO15 those alphanumeric characters whose code words are largely identical to the code words of the control symbols The representation can be effected by interchanginy the colour of the chaxacter with that of the background, for example. It is also possible to ~ 3 S~
provide the character with an underline in order to distinguish it from the noFmal alphanumerical characters which can be displayed.
The function of the control symbol can also be indicated to the user on the screen by the use of special symbols consisting of ~urther characters which indicate the ~unction of the corre~ponding control symbol mnemo-technically in abbreviated form.
An advantageous embodiment of a circuit arrangement `-10 for carrying out the proposed process comprises a switching stage which is supplied by the keyboard with a signal during the representation of the points of the screen assigned to the control symbols, and is effective during the read-out from the page stors of a code woxd ass~gned to a control symbol to supply the image control unit with a signal which triggers the representation of the special symbol on the screen.
If the special symbols consist of characters which indicate the function of the control symbols mnemo-technically in abbreviated form, it is advantageous to provide a further character generator, which stores data words assigned to the special symbols, and which emits the data words to the image control unit when code words assigned to the control symbols are read out from the page store.
The invention will now be described with reference to ihe drawings, in which:-Figure 1 is a set of diagrams illustrating a portionof a display row on a screen and corresponding zones in a page store;
~7--357~
Figure 2 is a set of diagralns illustrating a portion of a further display xow: ~n the screen and the related storage zones in the page storei Figure 3 is a set of diagrams illustrating portions of another display row on the screen; and Figure 4 is a block schematic circuit diagram of one exemplary circuit arrangement for the implementakion of the proposed process.
In the display ~ow represented by row a in Figure 1, it has been assumed that alphanumeric characters "A", "B" and "C" are represented in red, and to be in flashing form, whilst a graphic character G is repres~nted in green and flashing form.
The corresponding code words for the alphanumeric characters "A", "B" and "C" and for the graphic character G, together with their assigned control symbols, are all represented in the portion of the page store represented by row b. The code words are stored in binary coded ashion, but for reasons of clarity in the drawing they have been reproduced in the form of mnemo-technical abbreviations and gxaphic representations, which may be utilised in practical displays. Following a code word for the symbol "interspace" there is stored in the page store one code word for the control symbol "cCred" (alphanumeric character, red) and one code word for the control symbol "Bl on" (flashing).
Following two further code words for the symbol "interspace", there then follows the code words for the alphanumeric characters "A", "B" and "C", followed by the code words for the symbol "interspace", the control symbols "Gr gn" (graphic character, green) and "sep Gr" (punctiform graphic character, separated graphics), and for the graphic character G. The control symbols ~5~
" ~ red" and "Bl on" result in a ~lashin~ representation of the alphanumeric charactexs '~BC'I in xed~ ~imil~rl~ the control symbols "Gr gn" and "sep Gr" result in the repxe~entation o~
the graphic character G in green with punctiform elements.
S The same representation on the screen is also achieved if, as illustrated at row c, the control symbol "sep Gr" is arranged preceding the alphanumeric characters "AB~". In any particular case it is only operative at the point a~ which a graphic character such as G is represented. In the case of `10 representation on the screen in accordance with the display row represented in Figure 1 row a, it cannot be recognised where and in which sequence the individ~al control symbols are arranged, so that it is not readily possible to correct or to bring up to date the display row.
In the alternative case represented in Figure 2 it has been assumed that the alphanumeric characters "ABC" are not to be represented in flashing form, and that the graphic character G is to be still flashing, but composed of contiguous surface ( , elements, as shown in Figure 2, row a. The change can be made by inserting the control symbol "Bl off" (stop flashing) prior to the alphanumeric characters "ABC", and two control symbols, "con Gr" (surface~form graphic character, continuous graphics) and "Bl on", both of which are inserted prior to the graphic character G, as illustrated in Figure 2, row bD However, if the positions of the individual control s~mbols are known, it is possible to reach the same result by erasing the control symbols "Bl on" and "sep Gr" from the array shown in Figure 1 row c and inserting the control symbol "Bl on" prior to the graphic ~9_ ~S~7 charactex 5, to obtain the content sho~m in Figure 2 row c.
In order to be able to change the store content represented at row c of Figure 1 into the store content represented in row c of Figure 2, it is necessary to determine the positions of the control symbols. In accordance with the process, a key on the keyboard is operated which results in the representation of positions of the scxeen assigned to the control symbols by means of special symbols. During the representation , of the special symbols it i~ possible to block the representation of the other characters.
As illustrated in Figure 3 at a, the control symbols are represented by special symbols which contain alphanumeric characters. In order to be able to distinguish these selected alphanumeric characters from the basic alphanumeric characters normally to be represented on the screen, they may be represented inversely, that is to say with the background and foreground colours interchanged, or with an underlining. No further character generator is needed for the display device if the ( special symbols consist for example of those alphanumeric characters whose code words differ as little as possible from the code words of the corresponding control symbols. For example the code word for the control symbol "Bl on" differs from the alphanumeric character "H" only in the highest value binary character. In order to simplify the assignment of the special symbols to the control symbols for the user it is possible to display an explanatory text relating to the called up control symbols in known manner in an additional display xow on the screen.
Another possibility as regards the formation of the ~S'~7 special symbols consists in that, as shown in Figure 3, row _, mnemo-technical abbreviations of the control symbol are represented at the appropriate position. For this purpose, however, it is necessary to provide an additional character generator, or to extend the existing character generator, as two alphanumeric characters are arranged in each o~ these character positions.
Following the actuation of the corresponding key on the keyboard, all the control symbols are displayed simultaneously on the screen when employing the proposed process. In the event of a change in the screen content the user can now position the write mark at the appropriake position on the screen and modify the control symbol in question in a simple manner.
The display device which is illustrated schematically in Figure 4 is provided for the "tele-screen text" telecommunications service, and is connected via a modem M to a telephone line F. The modem M is Gonnected in known manner to a telephone handset FA.
Using the display device, on the one hand it is possible to call ( up items of data via the telephone line F from a central unit and to represent these items on a screen BS of a display unit AE, and on the other hand it is possible to construct or correct the screen contents by means of a keyboard TA~ and then to transfer these revised contents via the telephone line F to the central unit. Further screen contents can be stored in a peripheral store PS.
The display device contains a control unit ST which controls the time sequence, and normally contains a micro-processor. The control unit ST is connected to the keyboard TA. In addition the display device contains a page s~ore SP
~ ~ ~S'7~7 which stores code word~ CW of at least one screen content, i.e.
of one page. The page store SP is followed by an image control unit BST which emits video-signals to the display unit AE in dependence upon the content of the page s~ore. The image control unit BST contains a character generator Z which is addressed by code words CW and which contains data words assigned to the forms of the characters which are to be represented. Furthermore the display device contains a switching stage shown enclosed in a chain-dashed rectangle, which makes it possihle to display all the control symbols of a page stored in the page store SP.
This switching stage S contains a further character generator Zl which stores special symbols which contain mnemo-technical abbreviations~ as illustrated in row b of Figure 3.
Following the actuation of an appropriate switch on the keyboard TA, this character generator emits a signal Sl to the switching stage S.
The signal Sl is fed to A first input of an AND gate whose second input is supplied with the code words CW and whose output is connected to the address input of the character generator Zl. If, during the representation of the screen content, the code words CW of the characters and of the control symbols are read out from the page store SP, by means of the character generator Z in the image control unit BST the characters are displayed on the screen BS. ~hen the code words CW assigned to a control symbol are read out irom the page store SP, the character generator Z contains no corresponding data words so that it does not emit any video-signals. Since the data words CW are fed via the AND gate U to ~he character generator Zl and the latter contains special symbols which represen~ the control ~S7~t~
symbols, at the tLme ~f the read-out of the corresponding code words CW from the page stoxe SP, the data words assigned to the special symbols are read out from the character generator Zl and fed, by way of signals S2, to the image control unit BST. This produces corresponding video-signals which it emits to the display unit AE in order to represent the special symbols on the screen.
If si~ultaneous representation of the aphanumeric characters and the gxaphic characters is undesired, the signal Sl can also be fed to the image control unit BST where it will block the character generator Z.
With the aid o~ the proposed process, the described arxangement makes it possible to characterise not only the control symbols but also those points of the screen BS at which graphic patterns are to be represented in punctiform fashion, by the same arrangeme~t as that for the alphanumeric characters.
These graphic patterns are usually stored in a write/read s~ore from where they are called up under predetermined addresses (DRCS, dynamically redefinable character set). The addresses of these patterns are then stored at the corresponding positions in the page store. If these addresses are called up by means of the keyboard, the positions on the screen BS at which the corresponding graphic patterns are represented are displayed.
~s~
which the individual characte~s are represented. Graphic patterns are represented hy ~es~ectiye characte~ ~rXays each containing one graphic character co~posed of 2x3 graphic Ple~ents. The graphic patterns are composed from the combinations of light and dark graphic elements in the various colours, and it is not possible to change the colours within one character array.
The display device contains an image control unit which controls the representation of the characters on the screen.
The image control unit contains a character gene.rator which stores a predetermined supply of alphanumeric and graphic characters. With the use of code words which are stored in a page store and which represent the addresses of the character generator, data words assigned to the image points of the characters or to the graphic elements are read out from the character generators and fed to a display unit which contains the screen.
The properties of the characters which can be represented are determined by control symbols, which are likewise stored in the form of code words in the page store. The control symbols indicate, for example, in which colour the characters are to be represented, whether the characters are to be represented in a flashing or non-flashing manner, and whether at normal height or at double height. In the case of serial coding of the characters and of the control symbols, each position on the screen is assigned one zone of the page store provided for a code word. If a storage zone contains a code word of a control symbol, generally no character is represented at the corresponding position on the screen. A manner of assignment of code words to ~3~
~35~
characters and to control symbols is described in respect o serial coding, for ex~mple, in the magazine 'IFunkschau'' (1977), Vol. 18l pages 78-82.
In the case of parallel coding, ~he number of the binary characters of the code words assigned to the characters which can be represented is increased, so that each character can be accompanied by a control symbol forming accompanying information. In this case the gaps provided for the control ~ symbols are omitted, and characters can be represented anywhere on the screen. It is also possible to combine parallel coding with serial coding.
As the control symbols are not displayed in the normal page content, and therefore in the case of serial coding are indistinguishable from an "interspace" symbol on the screen, if the screen content must be sat up or amended it is not readily possible to recognise the positions of any control symbols which have already been stored~
It would be conceivable, following the actuation of a corresponding key on a keyboard provided for the setting up or processing of the screen content, to display a special symbol, for example the write mark, at every position at which a control symbol is stored. If a plurality of control symbols are stored consecutively, again it is impossible to recognise the position of a specific control symbol, for example, so that only that control symbol is amended.
It is also already known to display a text which characterises a control symbol in an additional display row at the lower edge of the screen whenever the write mark is ~4-~9S~
positioned on the screen at a position to which a control symbol is assigned. In this way it is possible to recognise the position of a control symbol which is to be modified. However, if the control symbol is firstly operative at another position, 5 it is firstly necessary to find this control symbol by means of the write mark. Furthermore, a relatively high circuitry outlay is needed, since the additional display row must be represented on the screen.
One object of the present invention is to provide a process whereby it is possible to determine that point of the screen of a display device which is assigned to a speciiic control symbol in a simple and Very rapid fashion.
The invention consists in a process for the xepresentation of control symbols on a screen of a display device which contains a page s~ore which can store code words which are assigned to alphanumeric and/or graphic characters to be displayed on the screen and control symbols which determine properties of these characters, a keyboard being provided by means of which the code words assigned to the characters and control symbols can be input into the page store, and an image control unit being provided together with a character generatcr which controls the representation of the characters on the screen, said process being such that actuation of a keyboard switch assigned to control symbols causes special symbols which characterise the control symbols in question to be represenced at all relevant positions on the screen assigned to a control symbol in the page store.
The process proposed in accordance with the invention 1~9S~37 has the advantage that the setting up, correction and up-dating of a screen content can be carried out simply and Yexy rapidly, since it is possible to directly display those positions of the screen which are assigned to the individual control symbols.
In order to achieve a clearly defined assignment of any represented characters to the related control symbols, it is advantageous to represent the alphanumeric and/or graphic characters during the representation of the special symbols.
Under certain circumstances it can also be advantageous to block the representation of the alphanumeric and/or graphic characters during the representation of the special symbols.
In order to be able to indicate on the screen the function of the control symbol to the user, it is advantageous for the representation of the special symbols on the screen to be accompanied simultaneously by a representation of texts characterising the corresponding control symbols, in an additional display row. For example, simult~neously to the representation of the special symbol "Bl", by way of text the word "flashing"
; is displayed in the additional display row.
A further character generator~ or an elaboration of the character generator already provided, is unnecessary if the special symbols consist of characters which are stored in the character gen~rator and which are represented in a special manner. It is expedient to use as special SymbO15 those alphanumeric characters whose code words are largely identical to the code words of the control symbols The representation can be effected by interchanginy the colour of the chaxacter with that of the background, for example. It is also possible to ~ 3 S~
provide the character with an underline in order to distinguish it from the noFmal alphanumerical characters which can be displayed.
The function of the control symbol can also be indicated to the user on the screen by the use of special symbols consisting of ~urther characters which indicate the ~unction of the corre~ponding control symbol mnemo-technically in abbreviated form.
An advantageous embodiment of a circuit arrangement `-10 for carrying out the proposed process comprises a switching stage which is supplied by the keyboard with a signal during the representation of the points of the screen assigned to the control symbols, and is effective during the read-out from the page stors of a code woxd ass~gned to a control symbol to supply the image control unit with a signal which triggers the representation of the special symbol on the screen.
If the special symbols consist of characters which indicate the function of the control symbols mnemo-technically in abbreviated form, it is advantageous to provide a further character generator, which stores data words assigned to the special symbols, and which emits the data words to the image control unit when code words assigned to the control symbols are read out from the page store.
The invention will now be described with reference to ihe drawings, in which:-Figure 1 is a set of diagrams illustrating a portionof a display row on a screen and corresponding zones in a page store;
~7--357~
Figure 2 is a set of diagralns illustrating a portion of a further display xow: ~n the screen and the related storage zones in the page storei Figure 3 is a set of diagrams illustrating portions of another display row on the screen; and Figure 4 is a block schematic circuit diagram of one exemplary circuit arrangement for the implementakion of the proposed process.
In the display ~ow represented by row a in Figure 1, it has been assumed that alphanumeric characters "A", "B" and "C" are represented in red, and to be in flashing form, whilst a graphic character G is repres~nted in green and flashing form.
The corresponding code words for the alphanumeric characters "A", "B" and "C" and for the graphic character G, together with their assigned control symbols, are all represented in the portion of the page store represented by row b. The code words are stored in binary coded ashion, but for reasons of clarity in the drawing they have been reproduced in the form of mnemo-technical abbreviations and gxaphic representations, which may be utilised in practical displays. Following a code word for the symbol "interspace" there is stored in the page store one code word for the control symbol "cCred" (alphanumeric character, red) and one code word for the control symbol "Bl on" (flashing).
Following two further code words for the symbol "interspace", there then follows the code words for the alphanumeric characters "A", "B" and "C", followed by the code words for the symbol "interspace", the control symbols "Gr gn" (graphic character, green) and "sep Gr" (punctiform graphic character, separated graphics), and for the graphic character G. The control symbols ~5~
" ~ red" and "Bl on" result in a ~lashin~ representation of the alphanumeric charactexs '~BC'I in xed~ ~imil~rl~ the control symbols "Gr gn" and "sep Gr" result in the repxe~entation o~
the graphic character G in green with punctiform elements.
S The same representation on the screen is also achieved if, as illustrated at row c, the control symbol "sep Gr" is arranged preceding the alphanumeric characters "AB~". In any particular case it is only operative at the point a~ which a graphic character such as G is represented. In the case of `10 representation on the screen in accordance with the display row represented in Figure 1 row a, it cannot be recognised where and in which sequence the individ~al control symbols are arranged, so that it is not readily possible to correct or to bring up to date the display row.
In the alternative case represented in Figure 2 it has been assumed that the alphanumeric characters "ABC" are not to be represented in flashing form, and that the graphic character G is to be still flashing, but composed of contiguous surface ( , elements, as shown in Figure 2, row a. The change can be made by inserting the control symbol "Bl off" (stop flashing) prior to the alphanumeric characters "ABC", and two control symbols, "con Gr" (surface~form graphic character, continuous graphics) and "Bl on", both of which are inserted prior to the graphic character G, as illustrated in Figure 2, row bD However, if the positions of the individual control s~mbols are known, it is possible to reach the same result by erasing the control symbols "Bl on" and "sep Gr" from the array shown in Figure 1 row c and inserting the control symbol "Bl on" prior to the graphic ~9_ ~S~7 charactex 5, to obtain the content sho~m in Figure 2 row c.
In order to be able to change the store content represented at row c of Figure 1 into the store content represented in row c of Figure 2, it is necessary to determine the positions of the control symbols. In accordance with the process, a key on the keyboard is operated which results in the representation of positions of the scxeen assigned to the control symbols by means of special symbols. During the representation , of the special symbols it i~ possible to block the representation of the other characters.
As illustrated in Figure 3 at a, the control symbols are represented by special symbols which contain alphanumeric characters. In order to be able to distinguish these selected alphanumeric characters from the basic alphanumeric characters normally to be represented on the screen, they may be represented inversely, that is to say with the background and foreground colours interchanged, or with an underlining. No further character generator is needed for the display device if the ( special symbols consist for example of those alphanumeric characters whose code words differ as little as possible from the code words of the corresponding control symbols. For example the code word for the control symbol "Bl on" differs from the alphanumeric character "H" only in the highest value binary character. In order to simplify the assignment of the special symbols to the control symbols for the user it is possible to display an explanatory text relating to the called up control symbols in known manner in an additional display xow on the screen.
Another possibility as regards the formation of the ~S'~7 special symbols consists in that, as shown in Figure 3, row _, mnemo-technical abbreviations of the control symbol are represented at the appropriate position. For this purpose, however, it is necessary to provide an additional character generator, or to extend the existing character generator, as two alphanumeric characters are arranged in each o~ these character positions.
Following the actuation of the corresponding key on the keyboard, all the control symbols are displayed simultaneously on the screen when employing the proposed process. In the event of a change in the screen content the user can now position the write mark at the appropriake position on the screen and modify the control symbol in question in a simple manner.
The display device which is illustrated schematically in Figure 4 is provided for the "tele-screen text" telecommunications service, and is connected via a modem M to a telephone line F. The modem M is Gonnected in known manner to a telephone handset FA.
Using the display device, on the one hand it is possible to call ( up items of data via the telephone line F from a central unit and to represent these items on a screen BS of a display unit AE, and on the other hand it is possible to construct or correct the screen contents by means of a keyboard TA~ and then to transfer these revised contents via the telephone line F to the central unit. Further screen contents can be stored in a peripheral store PS.
The display device contains a control unit ST which controls the time sequence, and normally contains a micro-processor. The control unit ST is connected to the keyboard TA. In addition the display device contains a page s~ore SP
~ ~ ~S'7~7 which stores code word~ CW of at least one screen content, i.e.
of one page. The page store SP is followed by an image control unit BST which emits video-signals to the display unit AE in dependence upon the content of the page s~ore. The image control unit BST contains a character generator Z which is addressed by code words CW and which contains data words assigned to the forms of the characters which are to be represented. Furthermore the display device contains a switching stage shown enclosed in a chain-dashed rectangle, which makes it possihle to display all the control symbols of a page stored in the page store SP.
This switching stage S contains a further character generator Zl which stores special symbols which contain mnemo-technical abbreviations~ as illustrated in row b of Figure 3.
Following the actuation of an appropriate switch on the keyboard TA, this character generator emits a signal Sl to the switching stage S.
The signal Sl is fed to A first input of an AND gate whose second input is supplied with the code words CW and whose output is connected to the address input of the character generator Zl. If, during the representation of the screen content, the code words CW of the characters and of the control symbols are read out from the page store SP, by means of the character generator Z in the image control unit BST the characters are displayed on the screen BS. ~hen the code words CW assigned to a control symbol are read out irom the page store SP, the character generator Z contains no corresponding data words so that it does not emit any video-signals. Since the data words CW are fed via the AND gate U to ~he character generator Zl and the latter contains special symbols which represen~ the control ~S7~t~
symbols, at the tLme ~f the read-out of the corresponding code words CW from the page stoxe SP, the data words assigned to the special symbols are read out from the character generator Zl and fed, by way of signals S2, to the image control unit BST. This produces corresponding video-signals which it emits to the display unit AE in order to represent the special symbols on the screen.
If si~ultaneous representation of the aphanumeric characters and the gxaphic characters is undesired, the signal Sl can also be fed to the image control unit BST where it will block the character generator Z.
With the aid o~ the proposed process, the described arxangement makes it possible to characterise not only the control symbols but also those points of the screen BS at which graphic patterns are to be represented in punctiform fashion, by the same arrangeme~t as that for the alphanumeric characters.
These graphic patterns are usually stored in a write/read s~ore from where they are called up under predetermined addresses (DRCS, dynamically redefinable character set). The addresses of these patterns are then stored at the corresponding positions in the page store. If these addresses are called up by means of the keyboard, the positions on the screen BS at which the corresponding graphic patterns are represented are displayed.
Claims (8)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:-
1. A process for the representation of control symbols on a screen of a display device which contains a page store which can store code words which are assigned to alphanumeric and/or graphic characters to be displayed on the screen and control symbols which determine properties of these characters, a keyboard being provided by means of which the code words assigned to the characters and control symbols can be input into the page store, and an image control unit being provided together with a character generator which controls the representation of the characters on the screen, said process being such that actuation of a keyboard switch assigned to control symbols causes special symbols which characterise the control symbols in question to be represented at all relevant positions on the screen assigned to a control symbol in the page store.
2. A process as claimed in claim 1, in which any alphanumeric and/or graphic characters are also represented during the representation of the special symbols.
3. A process as claimed in claim 1, in which representation of any alphanumeric and/or graphic characters is blocked during the representation of the special symbols.
4. A process as claimed in any one of claims 1 to 3, in which a text characterising the corresponding control symbols is represented in an additional display row simultaneously to the representation of the special symbols on the screen.
5. A process as claimed in claim 1, the special symbols consist of characters which are stored in the character generator and which are represented in known manner.
6. A process as claimed in claim 1, in which the special symbols consist of further characters which indicate the function of the correspond-ing control symbol mnemotechnically in abbreviated form.
7. A circuit arrangement for carrying out the process claimed in claim 1, in which a switching stage is provided which is supplied by a keyboard with a signal during the representation of those points on the screen assigned to the control symbols, and which is effective during the read-out from the page store of a code word assigned to a control symbol to supply an image control unit with a signal which triggers the representation of the special symbol on the screen.
8. A circuit arrangement as claimed in claim 7, in which a further character generator is provided which stores data words assigned to the special symbols, and which emits data words to the image control unit when code words assigned to the control symbols are read out from the page store.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3104675.4 | 1981-02-10 | ||
| DE19813104675 DE3104675A1 (en) | 1981-02-10 | 1981-02-10 | METHOD AND ARRANGEMENT FOR PRESENTING CONTROL CHARACTERS ON A SCREEN OF A DISPLAY DEVICE |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1195787A true CA1195787A (en) | 1985-10-22 |
Family
ID=6124483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000395750A Expired CA1195787A (en) | 1981-02-10 | 1982-02-08 | Process for the representation of control symbols on a screen of a display device |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0057754A3 (en) |
| CA (1) | CA1195787A (en) |
| DE (1) | DE3104675A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3244115A1 (en) * | 1982-11-29 | 1984-05-30 | Siemens AG, 1000 Berlin und 8000 München | Process and arrangement for the representation of control signs on a display unit |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5027332B1 (en) * | 1969-10-08 | 1975-09-06 |
-
1981
- 1981-02-10 DE DE19813104675 patent/DE3104675A1/en not_active Withdrawn
- 1981-10-22 EP EP81108728A patent/EP0057754A3/en not_active Ceased
-
1982
- 1982-02-08 CA CA000395750A patent/CA1195787A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3104675A1 (en) | 1982-08-26 |
| EP0057754A2 (en) | 1982-08-18 |
| EP0057754A3 (en) | 1982-09-15 |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |