DE2549893C2 - Circuit arrangement for the automatic repetition of data characters entered via a keyboard - Google Patents

Description

The invention relates to a circuit arrangement for the automatic repetition of a keyboard entered data characters encoded in binary code using a matrix field on whose Crossing points are arranged and bridged by keys on the keyboard and a counting device which periodically records the contact paths via a coding circuit and a multiplexing circuit and a keyboard evaluation circuit that takes over when the contact path is closed triggers a code character corresponding to the counter reading into a multi-level output memory.

For teleprinters with an electronic keyboard, it is known to have a separate permanent release key to arrange, when actuated the last keyed character is repeated. In general when the button is pressed, a fixed voltage level is switched through, which is a separate circuit arrangement activated to repeat the characters. This circuit arrangement is separate from the actual, keypad used for data entry.

The object of the invention is to provide a permanent release key for a teleprinter with an electronic keyboard to be arranged in the keypad in such a way that there is no special to control this key from the Keyboard control requires significantly different additional circuit. While pressing the continuous release button should the last typed character be automatically repeated continuously.

This object is achieved according to the invention in that in the matrix field for the input keys for

ίο a data character that triggers the repeat process Key is arranged and that a logical contact path associated with this key is closed Arrangement the transfer of the code character assigned to the key in the multi-level output memory blocks and that the logic arrangement generates a repeat signal, which is stored in the memory repetitive characters is assigned and that the character identified in this way via the logical Arrangement until the triggering button is opened

is repeatedly output from memory.

In a particularly advantageous embodiment According to the invention, the output memory has memory locations corresponding to the number of stages of the output memory for the repeat signal.

D'.e invention has the great advantage that there is no special feature for switching on the character repetition Button, which is controlled via a special circuit arrangement, requires. The permanent release button how the keys for the telex characters are routed on the keyboard circuit board, the different functions is recognized within the keyboard control. This reduces the costs for the Keyboard control considerably, in particular due to the saving of otherwise required, separate connection cables.

Because storage locations for the repeat signal are arranged in the output memory, in advantageously characters already stored in the memory that are not to be repeated before to repeating characters sent out. This means that when you press the continuous release button, the actual Send process at the keyboard output is not interrupted.

Embodiments of the invention are illustrated in the drawings and will be described below for example described in more detail. It shows

F i g. 1 shows a block diagram of the circuit arrangement according to the invention and
F i g. FIG. 2 is a block diagram of the keyboard evaluation circuit of FIG. 1.

A generator 1 oscillates at 66 kHz and supplies the control clock for a six-digit ring counter 2. To the Outputs of this ring counter 2, the respective counter readings can be tapped, which the code characters from correspond to a character set of 64 characters. Via a key matrix field 3 in connection with a Decoder circuit 4 and a multiplex circuit 5, the ring counter reading is continuously queried. 1st one Button pressed, d. H. If a contact is closed at a crossing point of the keyboard matrix 3, then one downstream keyboard evaluation circuit 6 is fed a so-called data signal. The following Known keyboard evaluation scheme 6 described in detail on the one hand has the task of providing a Unintentional multiple transmission of code characters, which is triggered by long pressing a data key could be to prevent, but on the other hand a clear statement about the contact state of the

Make keys taking into account key bouncing of the key contacts.

For this purpose, as shown in FIG. 2, the keyboard evaluation circuit 6 has two shift registers 7 and 8 arranged, which have 64 levels corresponding to the number of code characters, and which have a Clock line 9 are connected to the generator clock 1 and circulate "ur. The same clocks.

If there is now a data signal at input 10, i. H. if a key is pressed, this character is converted into the Shift register entered and is after a counter cycle 2 again at the output of the shift register 7 at. In connection with the recurring data signal, an AND element 11 sends an acceptance signal generated, which is fed to a gate circuit 12 and thus the transfer of the code character into the first stage of a 12-stage output memory 13 caused. The code character is then via a Sequence register 14, which is connected in parallel to the output memory, is pushed through the output memory 13 and then sent out.

In the keyboard evaluation circuit 6 itself, the data signal via an AND element 15 and a this AND-gate downstream OR gate 16 written in the shift register 8, at its Output it is present after another counter cycle. At this point in time is the one that triggers the data signal If the key is still pressed, the resulting takeover signal is suppressed, namely through the negated input of the AND element 11. At the same time, the data signal is sent via an AND element 17 and a downstream OR element 18 again into the shift register 7 and via the AND elements 19, 20,

21 is again written into the shift register 8.

In order to make a clear statement about the state of fasting, taking into account bouncing processes to get to the key contact is a cycle counter

22 in FIG. 1 arranged, the individual rounds of the ring counter 2 counts and after every 32nd cycle the AND gates 17 and 19, i.e. the inputs of the locks both shift registers for the duration of one cycle. The time between these two closings of the AND gates 17 and 18 corresponds approximately to the greatest length of the bouncing processes to be expected. Because of this Block the feedback of the outputs of the shift register to their inputs is blocked, so that so that when the key is opened, the missing data signal clears the shift registers. Simplified the shift register 7 is used d <_r repeat lock, to prevent the character from being repeated when a key is pressed for a longer period of time, whereas at the output of the shift register 8 a signal can be picked up which is a unique '; Statement below Consideration of the bouncing on the state of the button there.

According to the invention is now within the matrix field 3 a repeat button is arranged with which it is possible to repeat individual code characters as long as desired. Is z. B. pressed the repeat button, and damii at the output of the multiplexer 5 an associated data signal triggered, the subsequent keyboard evaluation circuit causes 6 an acceptance signal which is fed to an AND gate 23. Its second negated The input is connected to a decoding circuit 24 which, if one of the repetition tests assigned code character emits a signal. Through this link 23 is the takeover of this the code character assigned to the repeat key in the output memory 13 is prevented.

At the same time, the AND link 25 between the decoder circuit 24 and the output for the takeover pulse of the keyboard evaluation circuit 6 generates a repeat signal which is stored in a memory 26 and in the output memory 13 is entered. In the output memory 13 are corresponding to the number of stages of this output memory Storage locations for the repeat signal arranged. These memory locations run parallel to the Storage locations of the coding characters, so that the stored in the first level of the output memory A repeat signal is assigned to the coding character that is to be repeated when the repeat key is pressed can be. By allocating such additional memory space within the output memory 13 for the repeat signal ensures that the code characters stored in the memory, the should not be repeated, i.e. characters that are stored in memory spaces 2 to 12, undisturbed the output memory 13 can run out before the character to be repeated at the output of the output memory is applied and by the coupling of the last stage of the output memory 16 via an OR element 27 to the last level of the sequence register 14 assigned to the output memory 13 is repeated for so long until the repeat button opens again.

By opening the repeat key, an AND gate 28 generates a clear signal that the Memory 26 and the sequence register 14 is supplied and thus directly the repetition of the character stops. The link 28 then forms a cancellation signal when it is reported via the decoder 24 that the Repeat signal is present in the cycle of the circulation counter 2, the keyboard evaluation 6 reports that the key for the Repeat signal is no longer pressed, and if at the output of the output memory 13 a repeat signal plant.

For this purpose 2 sheets of drawings

Claims (3)

Patent claims: 1. Circuit arrangement for the automatic repetition of input via a keyboard Data characters encoded in binary code using a matrix field at its intersection points Contact paths to be bridged by keys on the keyboard are arranged and one Counting device that periodically determines the contact paths via a decoder circuit and a multiplex circuit scans and a keyboard evaluation circuit which, when the contact path is closed, the Acceptance of a code character corresponding to the counter in a multi-level output memory triggers, characterized in that in the Mairix field for the input keys for Data characters a key that triggers the repeat operation is arranged and that when the this key associated contact path a logical arrangement the takeover of the key assigned code character in the multi-level output memory (13) and that the logical Arrangement generates a repeat signal, which is stored in the memory (13) to be repeated Character is assigned and that the character identified in this way via the logical arrangement is output repeatedly from the memory (13) until the triggering button is opened. 2. Arrangement according spoke 1, characterized in that according to the number of stages of the Output memory (13) the output memory has storage locations for the repeat sign. 3. Arrangement according to one of claims 1 or 2, characterized in that the output stage in the output memory (13) allocated storage space for the repeat signal via an OR gate (27) in parallel with the register stage assigned to the output stage of one of the output memories switched sequence register (14) is in connection.