Demand access digital-communications system

Claim 2

In a data-communications system including a central signalutilizing station and a plurality of remote stations serially connected on a transmission line to the central station; delay means at each remote station for delaying data which may be present on the transmission line; first signal-generation means at each remote station; second signal-generation means at each remote station; means for transmitting a signal from said first signalgeneration means over said transmission line to the central signal utilizing station during the delay interval; and enabling means at the central signal-utilizing station responsive to said first generated signal for enabling the transmission of said second signal over the transmission line without overlap on other signals which may be on the transmission line.

Claim 3

A data-communications system in accordance with claim 1, wherein said enabling means includes storage means for storing data during transmission of said second signal from the remote station.

Claim 4

A data-communications system in accordance with claim 1, wherein said delay means comprises a shift register.

Claim 5

A data-communications system in accordance with claim 1, wherein said delay is of substantially equal time duration as said first generated signal.

Claim 6

A data-communications system in accordance with claim 1, wherein said delay is of greater time duration than said first generated signal.

Claim 7

A data-communications system in accordance with claim 3, wherein the bit length of said first generated signal is equal to the number of bits shifted by said shift register.

Claim 8

A data-communications system in accordance with claim 3, wherein the bit length of said first generated signal is less than the number of bits shifted by said shift register.

Claim 9

A data-communications system in accordance with claim 1, wherein said first signal is a coded access demand and said second signal is a message to be transmitted along the transmission line to the central signal-utilizing station.

Claim 10

In a communications loop containing a central computer and a plurality of remote stations, each remote location contAining a transmitter and a receiver, the improvement comprising: delay means at each remote location for delaying data on said communications loop for a delay equal to the message length of a message introduced during said delay at said remote location.

Claim 11

In a communications loop containing a central computer and a plurality of remote stations, each remote location contAining a transmitter and a receiver, the improvement comprising: delay means at each remote location for delaying data on said communications loop for a delay equal to the message length of a message introduced during said delay at said remote location.

Claim 14

A system in accordance with claim 10 whereby said message inserted into the communications loop at the remote source is of a length equal to or less than said delay and further including: means for sampling data on said transmission line; means for insertion of said remote station message ahead of said sample data; and control means responsive to said sample data for controlling said data insertion means to insert said additional message ahead of said sampled and delayed data. 12. A system for use with a remote source of calculated data in a communications loop comprising: at least one receiver; at least one transmitter; a delay in the communications loop between the transmitter and the remote source of calculated data; first data-insertion means for provision of a signal of predetermined duration ahead of delayed data in the communications loop for transmission to the remote source; and second data-insertion means responsive to the remote source for the insertion of additional data into the communications loop after the remote source has received the signal from the first data-insertion means.

Claim 15

A system in accordance with claim 12 wherein the duration of said signal of predetermined duration is equal to the delay in the communications loop.

Claim 16

In a data-processing system wherein data control words associated with each of a plurality of peripheral subsystems are employed to control information transfer between memory and the corresponding peripheral subsystem, the improvement comprising: a communications loop; delay means at at least one peripheral subsystem; data-generation means at at least one peripheral subsystem; and means associated with said delay means for controlling said data-combining means whereby data present on the line and peripherally generated data may be present simultaneously in said delay means without overlap.

Claim 17

In a data-processing system wherein data control words associated with each of a plurality of peripheral subsystems are employed to control information transfer between memory and the corresponding peripheral subsystem, the improvement comprising: a communications loop; delay means at at least one peripheral subsystem; data-generation means at at least one peripheral subsystem; and means associated with said delay means for controlling said data-combining means whereby data present on the line and peripherally generated data may be present simultaneously in said delay means without overlap.

Claim 18

A data-communications system comprising: a central computer containing a central source of data; a plurality of remote stations connected on a transmission line to the central computer, each remote station including a remote computer; a plurality of data sources at each remote station; means at each remote station for independently initiating transmittal of data at said central computer to the remote station; and means at each remote station for preventing message overlap on said transmission line among the plurality of remote stations.

Claim 19

A data-communications system comprising: a central computer containing a central source of data; a plurality of remote stations connected on a transmission line to the central computer, each remote station including a remote computer; a plurality of data sources at each remote station; means at each remote station for independently initiating transmittal of data at said central computer to the remote station; and means at each remote station for preventing message overlap on said transmission line among the plurality of remote stations.

Claim 20

a data-communications system comprising: a first storage means; second storage means; third storage means; a data-transmission line serially connecting said first, second and third storage means; means at said second and said third storage means for transmitting a first and second signal of predetermined length respectively to said first storage means; means at said first storage means for receiving said first and second signals and for transmitting third and fourth signals of predetermined length in response thereto to said second and third storage means respectively; means at said second and third storage means for receiving said third and fourth signals respectively and for transmitting fifth and sixth signals of variable length respectively to said first storage means in response to said third and fourth signals; means at said storage means for receiving said fifth and sixth signals and fOr transmitting seventh and eighth signals of variable length respectively in response thereto; means at said second and third storage means for receiving said seventh and eighth signals respectively; and means at said second and third storage means for inhibiting the transmission of said first and second signals when other signals are present on said transmission line and for inhibiting said fifth and sixth signals until said third and fourth signals are received at said second and third storage means respectively.

Claim 21

a data-communications system comprising: a first storage means; second storage means; third storage means; a data-transmission line serially connecting said first, second and third storage means; means at said second and said third storage means for transmitting a first and second signal of predetermined length respectively to said first storage means; means at said first storage means for receiving said first and second signals and for transmitting third and fourth signals of predetermined length in response thereto to said second and third storage means respectively; means at said second and third storage means for receiving said third and fourth signals respectively and for transmitting fifth and sixth signals of variable length respectively to said first storage means in response to said third and fourth signals; means at said storage means for receiving said fifth and sixth signals and fOr transmitting seventh and eighth signals of variable length respectively in response thereto; means at said second and third storage means for receiving said seventh and eighth signals respectively; and means at said second and third storage means for inhibiting the transmission of said first and second signals when other signals are present on said transmission line and for inhibiting said fifth and sixth signals until said third and fourth signals are received at said second and third storage means respectively.

Claim 22

A data-communications system comprising: first storage means; second storage means; third storage means; a data-transmission line connecting said first, second and third storage means; means at said second and said third storage means for transmitting a first and second signal of predetermined length respectively to said first storage means; means at said first storage means for receiving said first and second signals and for transmitting third and fourth signals of predetermined length in response thereto to said second and third storage means respectively; means at said second and third storage means for receiving said third and fourth signals respectively and for transmitting fifth and sixth signals of variable length respectively to said first storage means in response to said third and fourth signals; means at said storage means for receiving said fifth and sixth signals and for transmitting seventh and eighth signals of variable length in response thereto; means at said second and third storage means for receiving said seventh and eighth signals respectively; and means at said second and third storage means for inhibiting the transmission of said first and second signals when other signals are present on said transmission line and for inhibiting said fifth and sixth signals until said third and fourth signals are received at said second and third storage means respectively.

Claim 23

A data-communications system comprising: first storage means; second storage means; third storage means; a data-transmission line connecting said first, second and third storage means; means at said second and said third storage means for transmitting a first and second signal of predetermined length respectively to said first storage means; means at said first storage means for receiving said first and second signals and for transmitting third and fourth signals of predetermined length in response thereto to said second and third storage means respectively; means at said second and third storage means for receiving said third and fourth signals respectively and for transmitting fifth and sixth signals of variable length respectively to said first storage means in response to said third and fourth signals; means at said storage means for receiving said fifth and sixth signals and for transmitting seventh and eighth signals of variable length in response thereto; means at said second and third storage means for receiving said seventh and eighth signals respectively; and means at said second and third storage means for inhibiting the transmission of said first and second signals when other signals are present on said transmission line and for inhibiting said fifth and sixth signals until said third and fourth signals are received at said second and third storage means respectively.

Claim 24

A data-communications system comprising: first storage means; second storage means; third storage means; a data-transmission line serially connecting said first, second and third storage means; means at said second and said third storage means for transmitting a first and second signal of predetermined length respectively to said first storage means; means at said first storage means for receiving said first and second signals and for transmitting third and fourth signals of predetermined length in response thereto to said second and third storage means respectively; means at said second and third storage means for receiving said third and fourth signals respectively and for transmitting fifth and sixth signals of variable length respectively to said first storage means in response to said third and fourth signals; means at said storage means for receiving said fifth and sixth signals; and means at said second and third storage means for inhibiting the transmission of said first and second signals when other signals are present on said transmission line and for inhibiting said fifth and sixth signals until said third and fourth signals are received at said second and third storage means respectively.

Claim 25

A data-communications system comprising: first storage means; second storage means; third storage means; a data-transmission line serially connecting said first, second and third storage means; means at said second and said third storage means for transmitting a first and second signal of predetermined length respectively to said first storage means; means at said first storage means for receiving said first and second signals and for transmitting third and fourth signals of predetermined length in response thereto to said second and third storage means respectively; means at said second and third storage means for receiving said third and fourth signals respectively and for transmitting fifth and sixth signals of variable length respectively to said first storage means in response to said third and fourth signals; means at said storage means for receiving said fifth and sixth signals; and means at said second and third storage means for inhibiting the transmission of said first and second signals when other signals are present on said transmission line and for inhibiting said fifth and sixth signals until said third and fourth signals are received at said second and third storage means respectively.

Claim 26

A data-communications system comprising: a central data-storage means; a plurality of remote locations each connected to said central data-storage means in a communications loop and each remote location including a local data-storage means; means at each remote location for independently transmitting a message of a predetermined number of data bits to said central data-storage means; and control means at each remote location for controlling said last-mentioned means to inhibit transmission of said message when overlapping of other data on said transmission line would occur by the transmission of said message.

Claim 27

A data-communications system comprising: a central data-storage means; a plurality of remote locations each connected to said central data-storage means in a communications loop and each remote location including a local data-storage means; means at each remote location for independently transmitting a message of a predetermined number of data bits to said central data-storage means; and control means at each remote location for controlling said last-mentioned means to inhibit transmission of said message when overlapping of other data on said transmission line would occur by the transmission of said message.

Claim 28

A data-communications system in accordance with claim 19, further comprising: a plurality of cathode-ray tube display terminals aT each remote location, each of said terminals being capable of generating and receiving digital information independently of the other terminals at said remote location; multiplexing means at each remote location for polling each of said display terminals; and control means at each remote location for receiving a multiplexed input from said multiplexer of said digital information from said display terminals, said control means further comprising means for enabling the transmission of said message upon the receipt of said multiplexed digital information.

Claim 29

A Data-communications system in accordance with claim 20, wherein said control means is a digital computer and said means for inhibiting transmission of messages includes a priority interrupt of the program of said computer.

Claim 30

A data-communications system in accordance with claim 21, further including: means at said central data-storage means including a programmed digital computer for controlling the transmission of data from said central data-storage means to each remote location; means controlled by said last-mentioned digital computer for transmitting an additional message of a predetermined number of data bits in response to said first-mentioned message of a predetermined number of data bits to said control means at each remote location; and means at each remote location for generating an additional program interrupt in response to said additional message of a predetermined number of data bits whereby said digital information generated at said display terminals is transmitted to said central data storage means and the transmission of other data from other remote locations is inhibited until the end of said last-mentioned transmission.

Claim 31

A data-communications system in accordance with claim 22, further comprising: means at said central data-storage means for a block of data in response to the receipt at said central data-storage means of the data transmission from each remote location containing the multiplexed digital information from said display terminals associated with each remote location and means at each remote location for receiving said block of data and for decoding said block of data in accordance with the particular display terminal to which it is addressed.

Claim 32

A data-communications system comprising: a central computer containing a central source of data; a plurality of remote stations connected on a transmission line to the central computer, each remote station including a remote computer; a plurality of data sources at each remote station; means at each remote station for independently transmitting data to and receiving data from central computer; and means at each remote station for preventing message overlap on said transmission line among the plurality of remote stations.

Claim 33

A data-communications system comprising: a central computer containing a central source of data; a plurality of remote stations connected on a transmission line to the central computer, each remote station including a remote computer; a plurality of data sources at each remote station; means at each remote station for independently transmitting data to and receiving data from central computer; and means at each remote station for preventing message overlap on said transmission line among the plurality of remote stations.

Claim 34

A data-communications system in accordance with claim 24, wherein said means at each remote station for independently transmitting data to and receiving data from said central computer includes a plurality of display terminals.

Claim 35

A data-communications system in accordance with claim 25, wherein said display terminals are cathode-ray tube display terminals.

Claim 36

A data-communications system in accordance with claim 25, further comprising multiplexing means associated with said plurality of display terminals for preventing message overlap among said plurality of display terminals.

Claim 37

A data-communications system comprising: a central computer containing a central source of data; a plurality of remote stations connected on a transmission line to the central computer, each remote station including a remote computer; a plurality of data sources at each remote station; means at each remote station for independently transmitting data to and receiving data from other remote stations; and means at each remote station for preventing message overlap on said transmission line among the plurality of remote stations.

Claim 38

A data-communications system comprising: a central computer containing a central source of data; a plurality of remote stations connected on a transmission line to the central computer, each remote station including a remote computer; a plurality of data sources at each remote station; means at each remote station for independently transmitting data to and receiving data from other remote stations; and means at each remote station for preventing message overlap on said transmission line among the plurality of remote stations.