US3781856A - Terminal communication control system and method - Google Patents

Terminal communication control system and method Download PDF

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Publication number
US3781856A
US3781856A US00210640A US3781856DA US3781856A US 3781856 A US3781856 A US 3781856A US 00210640 A US00210640 A US 00210640A US 3781856D A US3781856D A US 3781856DA US 3781856 A US3781856 A US 3781856A
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US
United States
Prior art keywords
code
codes
control
terminal equipment
idle
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Expired - Lifetime
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US00210640A
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English (en)
Inventor
T Aizawa
T Sawada
Y Tauchi
T Kawamata
H Saya
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Fujitsu Ltd
Nippon Telegraph and Telephone Corp
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Fujitsu Ltd
Nippon Telegraph and Telephone Corp
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Assigned to NIPPON TELEGRAPH & TELEPHONE CORPORATION reassignment NIPPON TELEGRAPH & TELEPHONE CORPORATION CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). EFFECTIVE ON 07/12/1985 Assignors: NIPPON TELEGRAPH AND TELEPHONE PUBLIC CORPORATION
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L13/00—Details of the apparatus or circuits covered by groups H04L15/00 or H04L17/00
    • H04L13/02—Details not particular to receiver or transmitter
    • H04L13/08—Intermediate storage means
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/09—Digital output to typewriters

Definitions

  • ABSTRACT In a data processing system, a communication control system for terminal equipment, such as a typewriter, receives and processes control codes for that terminal equipment for controlling the operation thereof and, particularly, automatically inserts idle codes immediately after certain control codes such as for controlling line feed, tabulation, and carriage return operations. Control codes received by the control system from a central processing unit are collated with char- [30] Foreign Application Priority Data I Y f d f acter c asst lcation in ormation store in a memory 0 Dec,26, 1970 Japan 45/118994 the c nt ol yst fo detecting and identifying the [52] U S Cl 340/172 5 Gosh/13,02 predetermined control codes.
  • a signal-inserting circuit is actuated for inserting an idle code of prescribed length immedi- [56] Reierences Cited ately thereafter and thus prior to the next successive control code, to afford sufficient time for proper oper- UNITED STATES PATENTS ation of the terminal equipment.
  • This invention relates to data processing systems and, more particularly, to a communication control system for use therein, for receiving and processing data for control of terminal units such as typewriters or other equipment.
  • a terminal unit, such as a typewriter, of a data processing system performs a number of different functions or operations in response to various, different control codes applied thereto. These include the functions of typing individual letters or characters, as well as various non-typing functions, such as return, line feed, tabulation, and back space operations. In general, each of these non-typing functions requires a longer operating time than that for the operation of typing an individual letter or character. For simplicity, all of the non-typing functional codes are referred to hereinafter by the general term, typewriter control code.
  • each of these functions is identified by a corresponding, specific code consisting of one character presented in a suitable code. Accordingly, if the typewriter control codes are supplied successively at the normal character transmitting time intervals, the typewriter cannot perform its function satisfactorily. In conventional data processing systems, this problem is overcome by an operation performed within the central processing unit of the basic data processing system. More specifically, the central processing unit, when transmiting typewriter control codes together with letter or character codes, operates to insert one or more idle codes immediately after each typewriter control code. The idle codes are selected such that they do not interfere with the typewriter operation and thus have no control effect thereon.
  • the idle codes are selected to provide a sufficient operating time to enable the specific typewriter control function required to be performed by a given control code.
  • the insertion of such idle codes by the central processing unit increases the amount, or length, of the data required to be transmitted and presents an additional burden in the development of the associated software for the central processing unit.
  • the present invention overcomes these and other de' fects of prior art systems and particularly is directed to obviating the requirement, in conventional data processing systems, of providing the idle codes as aforedescribed; more specifically, the present invention comprises an improved communication control system which controls the terminal unit and automatically inserts idle codes to assure proper operation of the terminal unit.
  • FIG. 1 comprises a block diagram of a data processing system with which the communication control system of the invention may be utilized;
  • FIG. 2 comprises a more detailed block diagram of the communication control system of the invention, as incorporated in the data processing system of FIG. I.
  • the communication control system is utilized in a data processing system for receiving control codes from a central processing unit and presenting them to a terminal unit for control of the operation thereof.
  • the communication control system includes a permanent memory for storing a character classification table. Character request circuits generate a character request signal for requesting transmission of a character code from the central processing unit. When received, the code is stored in a character buffer in the control system.
  • That character is decoded and collated with the prestored characters of the classification table of the permanent memory to identify whether the code represents the operation of typing an individual character or letter, requiring what may be termed a standard time interval, or whether it comprises a typewriter control code representing a non-typing function of the terminal unit, and thus requiring a greater operating time than that for typing a character or letter.
  • timing means are enabled for inserting an appropriate number of idle codes subsequent to the typewriter control code in an assembly buffer, thereby to afford sufficient time for the control function to be performed.
  • the character request circuitry then requests a further character code from the central processing unit in timed relationship to the control code currently being processed, whereby the further control code is received in proper timed relationship with respect to the control function required by the previously received control code.
  • a control code as received, is recognized by the collation function as not comprising a typewriter control code, and thus only requiring the operation of typing an individual letter or character, the control code is processed without the insertion of idle codes and a character request signal is transmitted immediately to the central processing unit.
  • the control system of the invention therefore provides for the automatic insertion ofidle codes by recognition of each character code, as received, and thus the corresponding function to be performed. Accordingly, the insertion of idle codes by the central processing unit as in conventional prior art systems is obviated, greatly simplifying the necessary software employed in th central processing unit and reducing the length of the data required to be transmitted.
  • FIG. 1 there is shown a block diagram of a data processing system incorporating a communication control system in accordance with the invention.
  • a central processing unit CPU which transmits data through a multiplexing channel MXC to the communication control system CCU and, particularly, to an interface circuit [PC of the latter.
  • This data comprises various control codes requiring respectively corresponding functions to be performed by the terminal equipment, for example a typewriter, such as the function of typing specified, individual letters or characters as well as non-typing functions such as return, line feed, tabulation, and back space.
  • each of the circuit blocks CPU, MXC, IFC, TC, LC and LUT as shown in FIG. 1, may take the form of the corresponding circuits as disclosed in U.S. Pat. Nos. 3,337855 and 3,34l,8l 8.
  • the control system CCU furthermore includes a permanent memory PM storing a character classification table affording, in a collation-type operation, identification of each received typewriter control code.
  • a timer TM then operates to provide the necessary timing interval to permit proper operation ofthe terminal unit in response thereto, as is more fully described in relation to FIG. 2.
  • the timing control may be performed by a character counter provided in a temporary memory CM. In such an embodiment, the number of idle codes subsequent to each typewriter control code are counted thereby to establish the required duration of the timing interval.
  • a line character requesting circuit LCR activates a character requesting circuit LR to produce a character request signal.
  • This signal is supplied through the normally enabled gate 102 to an interface circuit lFC for transmission through the multiplexing channel MXC to the central processing unit CPU.
  • the unit CPU transmits a character code through the multiplexer channel MXC to the interface circuit lFC of the communication control system CCU.
  • the character code transmitted from the unit CPU to the character buffer CB may be either a typewriter control code or a code for the operation of typing an individual letter or character.
  • the character code thus received is transferred to the character buffer CE for temporary storage, the output of the buffer CB supplying the character code both to a second normally enabled gate IG! and a decoder DC.
  • the decoder DC operates in conjunction with the permanent memory PM, the latter having stored therein a character classification table identifying each of the typewriter control codes, as distinguished from the codes relating to typing of characters or numerals. Decoder DC operates to decode the character code received thereby for addressing the permanent memory PM; thus, the decoded signal from the decoder DC accesses the address of the permanent memory PM. In the event that the decoded character is not a typewriter control code, i.e. the decoded character represents a typing function code, no output is produced from the permanent memory PM because no corresponding information in said address to the typewriter control code has been stored beforehand.
  • the assembly buffer AB which receives the code from the gate lGl supplies the code to a serial to parallel converter SPC and then to the line unit LUT for activation of the terminal unit.
  • the character code is a typewriter control code, such as line feed, return, tabulation or back space of a typewriter
  • the information corresponding to the specific typewriter control code such as the signal 1", 2" and 3", indicating the idle code insertion interval
  • the information corresponding to the specific typewriter control code has been stored at the address of the memory which was addressed by the decoded character code.
  • An idle code insertion judging circuit IDJ responds to the information stored in register R6 to determine the additional time required for the thus identified function to be performed by the typewriter.
  • the circuit [01 controls timer TM in accordance with that function.
  • the idle code insertion judging circuit [D] decodes the information stored in the register BC by an inner decoder IDJ-DC to control a timer TM.
  • the timer TM has a number of timing circuits TMI, TMZ and TM3 and a selected one of the said circuits is activated in response to the output of the circuit ID].
  • the actuation time of the timer TM as established by the circuit lDJ may be for any of a plurality of periods of different lengths of time in excess of the standard time interval, and depending upon the specific typewriter control code as identified by the output from the permanent memory PM.
  • the actuating period for the return operation of the typewriter can be set to be longer than the actuating period for a back space operation.
  • the character classification table may produce an appropriate output representing a comparatively longer timer actuation period for a return code while producing an output representing a comparatively shorter timer actuation period for a back space code.
  • timer TM The output of timer TM is supplied to the disable inputs of the normally enabled gates I01 and I62 and thus for the duration of its actuation, disables those gates. Accordingly, the character requesting signal from the circuit LR is inhibited from being applied to the interface circuit lFC for the duration ofthat timing period. Similarly, transfer of any further character code from the character buffer CB to the assembly buffer AB is inhibited by disabling of the gate lGl.
  • the output of the timer TM is, as well, applied to AND gate AN. Therefore, when both the output of the timer TM and the transmit timing signal applied periodically from a transmit timing controller XTC appear, an idle code from the idle code generating circuit IDL is applied to the assembly buffer AB through the AND gate AN.
  • the idle code generating circuit lDL selectively controls the output levels on the eight output lines thereof, in accordance with an eight bit idle code. Specifically, each output line is connected with input lines labelled 0 or 1 through a patchboard P. Therefore, the output 0 or 1 appears at each of the output lines thereby establishing the idle code output signal.
  • the inhibit gates 1G1 and lG2 again are enabled to permit the aforedescribed transfer of the character request signal from the circuit LR through interface circuit IFC and, as well the transfer of the character from the character buffer CB to the assembly buffer AB.
  • the communication control CCU of the invention operates to insert automatically a suitable idle code or codes immediately after each typewriter control code without necessitating any operation at the central processing unit CPU. As a result, accurate data transmission and efficient data processing are assured.
  • a character counter or an output code counter may be utilized to establish the desired time interval for operation of the typewriter in response to each control code.
  • a character counter to perform this counting operation may be provided in the temporary memory CM(FIG. l) which may be incorporated in the line circuit LC (HO. 1).
  • a long mark signal, or other suitable signal may be employed in lieu of the idle code or idle codes to afford the necessary timing function.
  • the operating period allowed for each typewriter control code can be determined by selectively regulating the number of the idle codes which are inserted immediately after the typewriter control code as a function of the specific control operation.
  • the length of a mark signal may be regulated in accordance with the required control operation specified by the typewriter control code.
  • a timing interval of selectively controlled duration may be provided to assure proper operation of the typewriter.
  • the communication control system of the invention upon detection of a specific control code for operation of terminal equipment automatically inserts thereafter one or more additional codes having no control effect on the operation of the terminal equipment. Accordingly, the modification of the data to incorporate such idle codes subsequent to each control code, and which has heretofore been accomplished at a central processing unit, now is effected automatically by the communications control system. Accordingly, the software for the central processing unit is considerably simplified. Furthermore, interference to the terminal equipment by codes produced by the central processing unit is eliminated and accurate data transmission is assured.
  • a communication control system for receiving and processing the codes from the central processing unit comprising:
  • a communications control system as recited in claim 1 wherein there is further provided:
  • said gate is normally disabled and is enabled by said inserting means for the time interval established thereby.
  • timing code generating means generates a succession of idle codes
  • said applying means includes means for counting the number of idle codes inserted subsequent to the control code to establish a timing code of the required time interval.
  • said idle code generating means generates an idle code of relatively long duration
  • said applying means responsive to the identification of the control code for inserting the long duration idle code subsequent to each control code for the required time interval corresponding to the identified control code.
  • first gating means normally enabled to pass the character request signal for transmission and disabled by said inserting means for the duration of each timing code
  • second gating means normally enabled to transmit the received code from said temporary storage means to said output means, and disabled by said applying means for the duration of the idle code produced thereby.
  • a method of operation for receiving and processing the codes from the central processing unit comprising:
  • the step of generating includes providing a succession of idle codes as the timing code
  • the step of selectively inserting includes the insertion of a number of idle codes subsequent to each said control code to establish a timing code of the required time interval.
  • the step of generating includes providing a long duration signal as the timing code
  • the step of selectively inserting includes the insertion of a single long duration signal subsequent to the insertion of each control code for the required time interval of operation corresponding to the identified idle code.
  • a method of operation as recited in claim 10 further comprising:

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  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Human Computer Interaction (AREA)
  • Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Communication Control (AREA)
US00210640A 1970-12-26 1971-12-22 Terminal communication control system and method Expired - Lifetime US3781856A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45118994A JPS5040932B1 (enrdf_load_stackoverflow) 1970-12-26 1970-12-26

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US3781856A true US3781856A (en) 1973-12-25

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US (1) US3781856A (enrdf_load_stackoverflow)
JP (1) JPS5040932B1 (enrdf_load_stackoverflow)
DE (1) DE2163414B2 (enrdf_load_stackoverflow)
FR (1) FR2119744A5 (enrdf_load_stackoverflow)
GB (1) GB1368620A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4202040A (en) * 1976-04-27 1980-05-06 The United States Of America As Represented By The Secretary Of The Navy Data processing system
US4894798A (en) * 1986-06-20 1990-01-16 International Business Machines Corporation Automatic stop code insertion feature for a word processing apparatus

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3434117A (en) * 1967-04-24 1969-03-18 Ibm Automatic transmission speed selection control for a data transmission system
US3569943A (en) * 1969-04-02 1971-03-09 Ibm Variable speed line adapter
US3618031A (en) * 1970-06-29 1971-11-02 Honeywell Inf Systems Data communication system
US3636524A (en) * 1969-12-08 1972-01-18 Tel Tech Corp Multiplex communication system
US3639913A (en) * 1969-10-30 1972-02-01 North American Rockwell Method and apparatus for addressing a memory at selectively controlled rates
US3680051A (en) * 1970-07-29 1972-07-25 Honeywell Inf Systems Apparatus for maintaining character synchronization in a data communication system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3434117A (en) * 1967-04-24 1969-03-18 Ibm Automatic transmission speed selection control for a data transmission system
US3569943A (en) * 1969-04-02 1971-03-09 Ibm Variable speed line adapter
US3639913A (en) * 1969-10-30 1972-02-01 North American Rockwell Method and apparatus for addressing a memory at selectively controlled rates
US3636524A (en) * 1969-12-08 1972-01-18 Tel Tech Corp Multiplex communication system
US3618031A (en) * 1970-06-29 1971-11-02 Honeywell Inf Systems Data communication system
US3680051A (en) * 1970-07-29 1972-07-25 Honeywell Inf Systems Apparatus for maintaining character synchronization in a data communication system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4202040A (en) * 1976-04-27 1980-05-06 The United States Of America As Represented By The Secretary Of The Navy Data processing system
US4894798A (en) * 1986-06-20 1990-01-16 International Business Machines Corporation Automatic stop code insertion feature for a word processing apparatus

Also Published As

Publication number Publication date
DE2163414A1 (de) 1972-07-13
JPS5040932B1 (enrdf_load_stackoverflow) 1975-12-27
DE2163414B2 (de) 1974-09-12
GB1368620A (en) 1974-10-02
FR2119744A5 (enrdf_load_stackoverflow) 1972-08-04

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