EP0162736A1 - Graphic terminal oriented for multiwriting - Google Patents

Abstract

This graphics terminal comprises a display screen (30), a display management means (32), an input/output circuit (38) and a processing means (44). The processing means (44) comprises a storage means (46) and a control means (48) consisting of a processor (50) and of a means (49) for storing instructions for managing the graphics terminal. This control means (48) is able to: - load into the storage means (46) one or more write generators received from the remote equipment, - receive character codes to be displayed and control codes from the remote equipment, - activate a write generator in order to control the display as a function of the said received codes. <IMAGE>

Description

The present invention relates to a graphic terminal allowing the display of texts in all the natural, alphabetical, sylLabic and ideographic or coded scripts type "international phonetic transcription code" with the possibility of mixing Languages and their scripts on the same Lines for automatic processing.

Graphic terminals can be divided into two categories which form two generations of terminals: passive terminals and intelligent terminals. In both cases, the graphic display terminal is connected to a remote computer equipment which transmits the characters to be displayed and command codes.

The passive graphic terminals, which historically constitute the first generation, are often reduced to a low definition video monitor. The management of the screen is then ensured by the remote computer equipment. This is inconvenient because a non-negligible part of the processing time of the processor of this remote device is devoted to managing the screen, to the detriment of the "useful" processing time devoted to executing the programs. Under these conditions, the management of the screen is reduced to a minimum and the alphanumeric characters, from matrices frozen in read only memories (ROM), are often the only characters available.

To unload the remote equipment from the management of the screen, processing means comprising in particular an image memory, means for displaying on the screen the content of the image memory and a means for exchanging data codes with equipment remote to manage the display.

These data codes are either character codes to be displayed or command codes.

The command codes can be codes modifying the state of the screen, such as carriage return, line feed, rewind or cursor movement; The control codes can also be codes interrogating the graphic display terminal on the state of the screen, state defined by The value of each of the image points of the screen, the position of the cursor and the display state Cal-Lumé cursor, off, flashing).

The graphic terminal of the invention is a second generation graphic terminal.

The most common graphic terminals of this generation are alphanumeric terminals. The processing means in this case comprises a matrix of characters. And means for associating with a character code to be displayed received a character from the matrix and for displaying said character. The character matrix can simply be contained in a read-only memory. The processing means also comprises a means which defines the writing rules, that is to say the manner of associating the characters of the alphabet to form words and sentences. These writing rules are also contained in a read-only memory in the form of a series of instructions.

The character matrix is often unique. IT can however be replaced quite easily by another matrix of characters. It suffices to change the ROM containing the character matrix. This is possible because this read only memory contains the data defining the set of characters, and this is relatively easy to realize if said read-only memory is contained in a plug-in cartridge.

On the other hand, it is generally not possible to modify the writing rules in a simple manner. In fact, these appear in the form of instructions in a read-only memory which also contains other instructions executable by the processing means, such as instructions for managing the input-output circuits.

The current graphic screens are therefore intended for graphic and alphanumeric representations with fixed scripts, but are not intended for the generation of new characters governed by specific writing rules, which excludes their display in word processing.

However, the writing rules are not completely frozen; some can be configured. For example, it is often possible to choose between two character sizes, one corresponding to a character entered in a 5x7 point matrix, the other in a 10x14 point matrix. It is nonetheless true that these displayable scripts are scripts fixed in predefined and invariable matrices.

These modifications to the writing rules are however limited and do not allow simultaneous processing of simple characters such as Latin characters and complex characters such as ideograms.

Figures 1a to 1e, which show. texts in different languages and scripts, allow a better understanding of the importance of the possibility of modifying the writing rules for the display, by a single graphic terminal, of several different languages.

Figure 1a is a text in Latin characters. All the characters are contained in the same matrix of points generally comprising 5 × 7 points. This method enables regular tiling of the display screen and therefore simplifies the management of this screen. From a visual point of view, this method is not the best because the characters of small width such as "I" and characters such as "M" occupy the same volume, which gives an impression of enlargement of the text to some places and compaction in other places. The visual quality of the text remains acceptable, however.

Regular screen tiling cannot be achieved when the dimensions of two characters in a character set can be very different. For example, the text represented in FIG. 1b written in Ugaritic characters contains a character 4 of small width and a character 6 much wider. It is clear that the visual aspect of the text would be very bad if we allocated to each of these characters the same matrix of points. The writing rules cannot therefore be the same for the texts of FIGS. 1a and 1b. These rules being fixed for known graphic-alphanumeric terminals, The display of these two texts cannot be carried out by the same graphic-alphanumeric terminal.

FIG. 1c illustrates an alphabetical writing whose character association rules are different from the writing of FIGS. 1a and 1b. This figure represents a text in biblical Hebrew with related components whose direction of writing goes from right to left. All the characters are written in the same dot matrix as in FIG. 1a, but each dot matrix can contain, in addition to a character 8, 12, a punctuation mark 10, 14. The sign contained in The dot matrix 16 is not a single character extracted from The character matrix but consists of two characters: an alphabetic character 8 and a punctuation character 10. This writing rule which consists of adding punctuation marks below, in the middle or above the alphabetic characters is not found in The two previous writings.

In Figure 1d, there is shown another example of alphabetic writing. It is a text in the Arabic alphabet whose direction of writing goes from right to left. We notice a particular writing rule, typically cursive, which consists in Linking consecutive characters. Insofar as these characters can be linked, in initial, middle, final position or appear in isolated position, they take another form which is determined by the particular algorithm of the Arabic script which also knows related components. The most remarkable are those which cause the transformation of alit into hdmza or lam-alif.

FIGS. 1a to 1d therefore show that the alphabetic writings differ on the one hand by the set of characters used and on the other hand by writing rules which define the manner of associating these characters to compose a text. If on certain known graphic terminals several character sets are available, the writing rules are fixed. A single graphic terminal cannot therefore process texts as different as those represented in FIGS. 1a to 1d.

In FIG. 1e, a text has been represented in Chinese, that is to say in a non-Alphabetical writing. The complexity of each ideographic character forces them to be represented in a matrix of important points, for example 25x25 points. The writing rules are here close to the text of Figure 1a. Each character is defined in an identical dot matrix, but the size of this dot matrix is not the same in both cases. The writing rules are therefore not identical in the two cases.

Alphabetic scripts and non-Alphabetical scripts constitute the two classes of scripts. Note that the term writing should not be taken in a restrictive sense of writing a language. Musical notes, for example, form a character set of a writing that can be called alphabetical in that it presents The concatenation of a finite number of different signs governed by rules of succession forced and constrained, which can be processed by a graphic terminal.

Hieroglyphs and Ideograms are non-alphabetic writing characters. The character matrix is too large in this case (3000 characters for Ancient Egyptian, 57000 for Chinese, 45000 for Assyro-Babylonian cuneiforms) to be integrated into a memory of the graphic terminal. These characters are therefore stored on a mass memory such as a floppy disk or a hard disk addressable by the remote computer equipment to which the graphic terminal is connected. Instead of transmitting a simple code associated with the characters to be displayed, as in the case of alphabetic writing, the IT equipment must here transmit the value of each of the points in the matrix of points corresponding to the character to be displayed.

The code of a character to be displayed is therefore totally different depending on whether it is an alphabetical writing or a non-alphabetical writing. The Known graphic terminals cannot therefore process these two writes simultaneously, since the transmission protocol between the terminal and the remote computer equipment is fixed.

The objective of the invention is to remedy these drawbacks. To this end, the graphic terminal of the invention comprises means for loading from the remote terminal one or more write generators. It comprises in particular a storage means and a control means. The latter is capable of loading into said storage means sets of instructions and data received from the remote equipment to which the graphic terminal is connected, each of these sets defining a write, that is to say the whole displayable characters and Rules for associating these characters to form words and sentences.

The graphic terminal of the invention can thus treat any language in its original writing or several different languages typologically in their original scriptures with the possibility of mixing words of the various languages in their different scriptures on one or on several lines. screen according to their own rules and whatever the meaning of each of these scripts. To change the language, it suffices that the control means has loaded into memory one or more writing generators received from the remote terminal.

The graphic terminal of the invention is not subject to the file management system defined by the remote equipment equipped with a standard interface, for example of type RS 232 C, it is compatible with all existing computer systems thanks to à The flexibility of downloading the generators tureset to the universality of this interface. It can also be connected to any remote device by keeping its own graphic faculties whatever the file management system used.

According to a characteristic of the graphic terminal according to the invention, for each alphabetic writing generator, the storage means comprises an instruction zone defining the writing rules and a data zone defining a series of characters.

According to another characteristic of the graphic terminal according to the invention, for each non-alphabetic writing generator, the storage means comprises an instruction zone defining the writing rules.

• - un champ contenant Le nom de La commande,
• - un champ contenant Le nombre de points d'image concernés par La commande,
• - un champ contenant La valeur d'une suite de points d'image.

According to another characteristic of the graphic terminal according to the invention, the code for writing or reading a sequence of image points comprises:

• - a field containing the name of the order,
• - a field containing the number of image points concerned by the order,
• - a field containing the value of a series of image points.

Writing begins at the point designated by Cursor position. The cursor can be moved or not according to the command.

In the case of a monochrome graphic terminal, and according to a characteristic of the invention, the field containing the value of a series of image points contains one bit per image point and possibly padding bits.

• - les figures 1a à 1e, déjà décrites, illustrent différents systèmes d'écriture alphabétique et non-alphabétique,
• - La figure 2 est un synoptique du terminaL graphique selon l'invention,
• - Les figures 3a et 3b illustrent le format d'un code de caractère à afficher et un caractère affiché dans le cas d'un système d'écriture alphabétique,
• - Les figures 4a et 4b illustrent respectivement le format d'un code d'affichage d'une série de points de L'écran et L'affichage correspondant.

The characteristics of the invention will appear better after the following description of an embodiment given by way of illustration but not limitation, with reference to the drawings appended to which:

• FIGS. 1a to 1e, already described, illustrate different alphabetic and non-alphabetic writing systems,
• FIG. 2 is a block diagram of the graphic terminaL according to the invention,
• FIGS. 3a and 3b illustrate the format of a character code to be displayed and a character displayed in the case of an alphabetic writing system,
• - Figures 4a and 4b respectively illustrate the format of a display code of a series of points on the screen and the corresponding display.

FIG. 2 shows a synoptic table of the graphic terminal according to the invention. It includes a display screen 30, a display management means 32 consisting of a graphics processor 34 and an image memory 36, an input-output circuit 38 for exchanging data with L ' remote equipment 40 via a bidirectional link or bus 42, and a processing means 44.

This processing means 44 comprises a processor 50 and a storage means 49, which together form the control means 48; the processing means 44 also comprises a storage means 46 which comprises the series or series of character matrices as well as the writing rules thus forming one or more writing generators. The control means 48 manages the reception of the codes received from the remote system and, as a function of these codes, activates one of the write generators.

This control means 48 also includes a direct access unit to the memory 47 making it possible to accelerate the exchanges with the graphics processor 34.

The input-output circuit 38, The graphics processor 34 and The storage means 46, 47 and 49 are connected to the processor 50 by a bus 52. Likewise, the image memory 36 is connected to the graphics processor 34 by a bus 54. Finally, the screen 30 is connected to the graphics processor 34 by a channel 56.

The graphics processor 34 performs a copy of the content of the image memory 36 on the screen 30. It also receives orders from the processor 50 executing the instructions contained in the storage means 49 to modify the content of the memory of picture 36.

• - Les fonctions classiques de gestion de L'écran : retour chariot, saut à La ligne, remise à zéro de L'affichage, retour en arrière, déplacement du curseur, etc...
• - La recopie de toute zone rectangulaire de L'écran vers une autre zone de même dimension,
• - Le zoom temporaire de toute zone rectangulaire de L'écran,
• - La mémorisation dans Le moyen de mémorisation 46 des données et instructions reçues de L'équipement distant par L'intermédiaire du circuit d'entrée-sortie 38,
• - L'émission vers L'équipement distant de codes indiquant L'état de L'écran (position du curseur, état d'affichage d'un point d'image,...).

The instructions contained in the storage means 49 constitute the basic functions for managing the graphic terminal. Without being exhaustive, one can cite among these functions:

• - Classic screen management functions: carriage return, line feed, display reset, backspace, cursor movement, etc.
• - The copy of any rectangular area of the screen to another area of the same dimension,
• - The temporary zoom of any rectangular area of the screen,
• - The storage in the storage means 46 of the data and instructions received from the remote equipment via the input-output circuit 38,
• - The transmission to remote equipment of codes indicating the state of the screen (position of the cursor, display state of an image point, ...).

The storage means 49 generally contains a write generator used by default, that is to say in the absence of a write generator loaded in the storage means 46.

- The instructions contained in the storage means 46 in particular control the size of the matrix of points in which is inscribed a character to be displayed -this size is not necessarily The same for all the characters-, The possible connections between, consecutive characters, etc ... These instructions also make it possible to fix the parameters of the functions of screen management contained in the storage means 46, such as for example the number of lines of image points corresponding to the "line feed" function, this number being linked to the size of the matrix of points in which they are characters are inscribed.

The operation of the graphic terminal is as follows. On power-up, the processor 50 executes a series of instructions from the storage means 49 to initialize the graphics terminal. It then waits for commands from the remote equipment 40 which can command it to load into the storage means 46 one or more write generators received from the remote equipment 40 by the input-output circuit 38. In this case , processor control is then given to the instructions of a write generator, chosen as a function of the codes received, loaded into the storage means 46 which controls the execution of the write functions.

We will now detail the format of the codes received and issued by the graphic display terminal.

FIG. 3a shows the format of the code of a character to be displayed in the case of an alphabetical writing with a small number of characters. This code is very simple. One can use for example the ASCII code in which a byte is associated with each character. This code can be preceded or followed by a control code to indicate in particular The writing generator to be activated, if several writing generators are loaded in the storage means 46.

Order codes can also be transmitted in a known manner by a byte in the ASCII code.

FIG. 4a shows the format of the code for writing a series of image points. This format is used for point-to-point transmission of characters in the case of a non-alphabetic writing system. But it can also be used if the writing system is of the alphabetical type for processing other than the display of characters.

• - le nom de la commande,
• - le nombre de points d'image concernés,
• - la valeur de chacun de ces points d'image. L'écriture commence au point désigné par le curseur, le curseur peut être ou ne pas être déplacé suivant la commande.

The code represented in FIG. 4a has 3 fields which respectively contain:

• - the name of the order,
• - the number of image points concerned,
• - the value of each of these image points. The writing begins at the point designated by the cursor, the cursor may or may not be moved depending on the command.

In the case of a monochrome graphic terminal, the value of each point is reduced to a single bit.

The sizes of the different fields can be in order: two bytes, for the name of the command, one or two bytes for the number of image points and (N + 6) / 7 bytes for the value of the dots. image, where N is the number of image points. If the number N is not a multiple of 7, only the least significant bits of the last byte will be used, the most significant bits remaining are ignored.

FIG. 4b shows the state of the screen after reception of the writing code for a series of image points in which N = 5 and S = '11001011'. Only the 5 least significant bits of S are significant. They indicate in ascending order the on or off state of the image points of coordinates (I, J), (I, J + 1), (I, J + 2), (I, J + 3) and (I, J + 4), I and J being the coordinates of the cursor.

It is noted that the format of the writing code of FIG. 4a can also be used to indicate to the remote terminal the state of N picture points. These two codes will be distinguished by Their name, that is to say a value different from the first field.

This format can be simplified in the case of Reading or Writing a single image point. In writing, the name of the code can be different depending on whether you want to turn the picture point on or off. In this case, the writing or reading of an image point is represented by a code comprising only the first field of the code of FIG. 4a.

The format of FIG. 4a makes it possible, compared with the prior state of the art, to reduce the data rate between the remote equipment and the graphic terminal for displaying texts in a non-alphabetic writing system.

Claims (7)

1. Multi-writing oriented graphic terminal comprising a display screen (30), a display management means (32) provided with an image memory (36), an input-output circuit (38) for receiving from remote computer equipment (40) character codes to be displayed and control codes and processing means (44), said graphic terwinal being characterized in that said processing means (44) comprises a storage means (46) and a control means (48), said control means being able to: - load into the storage means (46) one or more write generators received from the remote equipment, - receive character codes to display and control codes from the remote equipment, - activate a writing generator to control the display as a function of said codes received. 2. graphic termininaL according to claim 1, characterized in that the control means (48) comprises a processor (50) and a memory (49) containing instructions for managing the terminal, said processor being able to execute said instructions. 3. Graphic terminal according to claim 2, characterized in that it further comprises a direct memory access unit (47). 4. graphic terminal seion The one that claims 1 to 3, characterized in that for each alphabetic writing generator, the storage means (46) comprises an instruction zone defining the writing rules and a data area defining a character matrix. 5. Graphic terminal according to any one of claims 1 to 3, characterized in that for each non-alphabetic writing generator, the storage means (46) comprises an instruction zone defining the writing rules. 6. Graphic terminal according to any one of claims 4 and 5, characterized in that the code for writing a series of image points comprises: - a field containing the name of the command, - a field containing the number of image points concerned by the command, - a field containing the value of a series of image points. 7. Graphic terminal according to claim 6 in LequeL The display screen (30) is monochrome, characterized in that the field containing the value of a series of image points contains one bit per image point and possibly padding bits.

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