Process for data communication between data processing systems

Claim 2

In a data processing system comprising a central computer interconnected with at least one satellite computer, a method of operating said central computer and satellite computer to enable communication therebetween comprising the steps of: a. said satellite computer signaling said central computer that at least one transaction needs processing, b. said central computer, in response to said signaling, communicating to said satellite computer the identity of one of a plurality of storage areas in said central computer''s memory, c. said satellite computer storing in said identified storage area an operation code word indicating that either transmission of data to the central computer or retrieval of data from the central computer is desired, d. said central computer, in response to said operation code, storing in an available one of said plurality of storage areas information indIcating either that data is to be transmitted to a particular location in said central computer''s memory or that data is to be retrieved from a particular location in said central computer''s memory, and e. said satellite computer either transmitting to or retrieving data from said central computer''s memory in accordance with said information.

Claim 3

A process as in claim 1 wherein step (a) further comprises the steps of: f. said satellite computer incrementing a special interrupt count stored in said central computer''s memory by an amount equal to the number of transactions needing processing, and g. said satellite computer sending an interrupt signal to said central computer.

Claim 4

adding one to an unanswered special interrupt count NUASI if no channel mailbox is available, otherwise going to step (4),

Claim 5

adding one to an unanswered special interrupt count NUASI if no channel mailbox is available, otherwise going to step (4),

Claim 6

returning to step (1),

Claim 7

returning to step (1),

Claim 8

A process as in claim 2 wherein step (b) further comprises the steps of: h. said central computer, in response to said interrupt signal, selecting an available one of said plurality of storage areas, i. said central computer sending an interrupt signal to said satellite computer with an indication of the identity of said selected storage area, and j. said central computer performing steps (h) and (i) for each count in said special interrupt count.

Claim 9

A process as in claim 3 further comprising the step of: k. said satellite computer, following the performance of step (c), sending an interrupt signal to said central computer with an indication of the identity of said selected storage area.

Claim 10

identifying an available channel mailbox,

Claim 11

identifying an available channel mailbox,

Claim 12

storing a first command word in said identified channel mailbox,

Claim 13

storing a first command word in said identified channel mailbox,

Claim 14

A process as in claim 4 wherein step (d) further comprises the steps of: l. said central computer, in response to the interrupt signal of step (k), selecting an available one of said plurality of storage areas, m. said central computer storing in the storage area selected in step (1) a command word indicating either that data is to be transmitted to or retrieved from said central computer''s memory and information identifying the address in said central computer''s memory to which such data is to be transmitted or from which such data is to be retrieved, and n. said central computer sending an interrupt signal to said satellite computer with an indication of the identity of the storage area selected in step (L).

Claim 15

A process as in claim 5 further comprising the step of: o. said satellite computer retrieving the contents of the storage area selected in step (l) prior to the performance of step (e).

Claim 16

storing the identity of said identified channel mailbox in MBXA,

Claim 17

storing the identity of said identified channel mailbox in MBXA,

Claim 18

sending an interrupt signal to said satellite computer together with the identity of said identified channel mailbox,

Claim 19

sending an interrupt signal to said satellite computer together with the identity of said identified channel mailbox,

Claim 20

In a data processing system comprising a central computer and at least one satellite computer interconnected by a communication channel, said central computer including a memory to which both the central computer and the satellite computer have direct access, said memory including a first area for storing control information and a plurality of other areas utilized for preparing for the transmission of data between said central computer and said satellite computer, said other areas each hereinafter referred to as a channel mailbox, a process of transmitting data between said central computer and said satellite computer comprising the steps of: a. said satellite computer incrementing a special interrupt count in said first memory area by an amount equal to the number of transmissions to be made and sending an interrupt signal to said central computer, b. said central computer, in response to said interrupt signal, selecting an available channel mailbox MBX(i), storing therein a first command word, and sending an interrupt signal to said satellite computer together with information identifying MBX(i), c. said satellite computer, in response to the interrupt signal of step (b), retrieving said first command word from MBX(i), storing in MBX(i) an operation code word in response to said first command word, said code word indicating either that data is to be stored in said central computer''s memory by said satellite computer or that data is to be retrieved by said satellite computer from said central computer''s memory, and sending an interrupt signal to said central computer together with informaTion identifying (MBX(i), d. said central computer, in response to the interrupt signal of step (c), selecting an available channel mailbox MBX(j), storing therein a second command word if said operation code word indicates that data is to be stored in said central computer''s memory by said satellite computer, storing therein a third command word if said operation code word indicates that data is to be retrieved by said satellite computer from said central computer''s memory, storing therein the address in the central computer''s memory where such data is to be stored or from where such data is to be retrieved, and sending an interrupt signal to said satellite computer together with information identifying MBX(j), and, e. said satellite computer storing data in the memory address specified in MBX(j) if said second command word is stored in MBX(j) or retrieving data from such memory address if said third command word is stored in MBX(j).

Claim 21

In a data processing system comprising a central computer and at least one satellite computer interconnected by a communication channel, said central computer including a memory to which both the central computer and the satellite computer have direct access, said memory including a first area for storing control information and a plurality of other areas utilized for preparing for the transmission of data between said central computer and said satellite computer, said other areas each hereinafter referred to as a channel mailbox, a process of transmitting data between said central computer and said satellite computer comprising the steps of: a. said satellite computer incrementing a special interrupt count in said first memory area by an amount equal to the number of transmissions to be made and sending an interrupt signal to said central computer, b. said central computer, in response to said interrupt signal, selecting an available channel mailbox MBX(i), storing therein a first command word, and sending an interrupt signal to said satellite computer together with information identifying MBX(i), c. said satellite computer, in response to the interrupt signal of step (b), retrieving said first command word from MBX(i), storing in MBX(i) an operation code word in response to said first command word, said code word indicating either that data is to be stored in said central computer''s memory by said satellite computer or that data is to be retrieved by said satellite computer from said central computer''s memory, and sending an interrupt signal to said central computer together with informaTion identifying (MBX(i), d. said central computer, in response to the interrupt signal of step (c), selecting an available channel mailbox MBX(j), storing therein a second command word if said operation code word indicates that data is to be stored in said central computer''s memory by said satellite computer, storing therein a third command word if said operation code word indicates that data is to be retrieved by said satellite computer from said central computer''s memory, storing therein the address in the central computer''s memory where such data is to be stored or from where such data is to be retrieved, and sending an interrupt signal to said satellite computer together with information identifying MBX(j), and, e. said satellite computer storing data in the memory address specified in MBX(j) if said second command word is stored in MBX(j) or retrieving data from such memory address if said third command word is stored in MBX(j).

Claim 22

returning to step (1),

Claim 23

returning to step (1),

Claim 24

A process as in claim 7 further comprising the steps of performing step (b) once for each count of said special interrupt count.

Claim 25

going to step (10) if a terminate interrupt signal and channel mailbox designation has been received from said satellite computer, otherwise going to step (22),

Claim 26

going to step (10) if a terminate interrupt signal and channel mailbox designation has been received from said satellite computer, otherwise going to step (22),

Claim 27

In a data processing system comprising a central computer and at least one satellite computer interconnected by a communication channel, and a plurality of input and output terminals connected to said satellite computer, said central computer including a memory in which both the central computer and the satellite computer may store data and from which both the central computer and satellite computer may retrieve data, said memory including a first area, MBXA, for storing control information and a plurality of other areas, each hereinafter referred to as a channel mailbox, utilized for communication between said central computer and said satellite computer, and said satellite computer including a memory, a method of operating said satellite computer to enable it to communicate with said central computer comprising the steps of: a. storing in a first rotating queue in said satellite memory a signal representing the identity of a terminal requesting service and incrementing by one a special interrupt count ICCSPC in said satellite memory, in response to a request for service from the terminal, b. storing in a second rotating queue in said satellite memory the identity of the channel mailbox specified in MBXA and incrementing by one a central computer interrupt count ICC6CT in said satellite memory, in response to an interrupt signal from said central computer, c. going to step (d) if ICC6CT 0, otherwise going to step (i), d. going to step (e) if ICCSPC not = 0, otherwise going to step (n), e. increasing a special interrupt count IC in MBXA by the number of counts in ICCSPC, f. setting ICCSPC 0, g. sending an interrupt signal to said central computer, h. returning to step (c), i. decrementing ICC6CT by one, j. retrieving the next entry from said second retating queue, k. retrieving the contents of the channel mailbox identified by said next entry, l. performing certain subroutines in response to the presence of various command words in said channel mailbox contents, m. returning to step (c), and n. terminating the operation.

Claim 28

In a data processing system comprising a central computer and at least one satellite computer interconnected by a communication channel, and a plurality of input and output terminals connected to said satellite computer, said central computer including a memory in which both the central computer and the satellite computer may store data and from which both the central computer and satellite computer may retrieve data, said memory including a first area, MBXA, for storing control information and a plurality of other areas, each hereinafter referred to as a channel mailbox, utilized for communication between said central computer and said satellite computer, and said satellite computer including a memory, a method of operating said satellite computer to enable it to communicate with said central computer comprising the steps of: a. storing in a first rotating queue in said satellite memory a signal representing the identity of a terminal requesting service and incrementing by one a special interrupt count ICCSPC in said satellite memory, in response to a request for service from the terminal, b. storing in a second rotating queue in said satellite memory the identity of the channel mailbox specified in MBXA and incrementing by one a central computer interrupt count ICC6CT in said satellite memory, in response to an interrupt signal from said central computer, c. going to step (d) if ICC6CT 0, otherwise going to step (i), d. going to step (e) if ICCSPC not = 0, otherwise going to step (n), e. increasing a special interrupt count IC in MBXA by the number of counts in ICCSPC, f. setting ICCSPC 0, g. sending an interrupt signal to said central computer, h. returning to step (c), i. decrementing ICC6CT by one, j. retrieving the next entry from said second retating queue, k. retrieving the contents of the channel mailbox identified by said next entry, l. performing certain subroutines in response to the presence of various command words in said channel mailbox contents, m. returning to step (c), and n. terminating the operation.

Claim 29

going to step (11) if said first command word is present in the channel mailbox designated in step (9), otherwise going to step (18),

Claim 30

going to step (11) if said first command word is present in the channel mailbox designated in step (9), otherwise going to step (18),

Claim 31

A method as in claim 9 wherein step (l) comprises the following steps if a first command word is present in said channel mailbox contents: o. fetching one of a plurality of operation codes from the terminal identified by the next entry of said first rotating queue, p. storing in a portion SMBX of said satellite computer''s memory said fetched operation code and the identity of the terminal identified by said next entry of said first rotating queue, q. transferring the contents of SMBX to the channel mailbox identified by said next entry of said second rotating queue, r. sending a terminate interrupt signal to said central computer identifying the channel mAilbox in which the contents of SMBX were stored in step (q), s. returning to step (c).

Claim 32

A method as in claim 10 wherein step (l) comprises the following steps if a second command word is present in said channel mailbox contents: t. storing data at that address in the central computer''s memory specified by said channel mailbox contents, u. storing information in SMBX indicating that data has been stored in the central computer''s memory, v. returning to step (q).

Claim 33

going to step (12) if a first operation code is present in said designated channel mailbox, otherwise going to step (17),

Claim 34

going to step (12) if a first operation code is present in said designated channel mailbox, otherwise going to step (17),

Claim 35

A method as in claim 11 wherein step (l) comprises the following steps if a third command word is present in said channel mailbox contents: w. retrieving data from that address in the central computer''s memory specified by said channel mailbox contents, x. storing information in SMBX indicating that data has been retrieved from the central computer''s memory, and y. returning to step (q).

Claim 36

storing in a table of line descriptions in said central computer''s memory the identity of the terminal specified in said designated channel mailbox,

Claim 37

storing in a table of line descriptions in said central computer''s memory the identity of the terminal specified in said designated channel mailbox,

Claim 38

storing a second operation code and a second command word in said designated channel mailbox,

Claim 39

storing a second operation code and a second command word in said designated channel mailbox,

Claim 40

In a data processing system comprising a central computer and at least one satellite computer interconnected by a communication channel, and a plurality of input and output terminals connected to said satellite computer, said central computer including a memory having a first area, MBXA, for storing control information and a plurality of other areas, each hereinafter referred to as a channel mailbox, utilized for communication between said central computer and said satellite computer, a method of operating said central computer to enable it to communicate with said satellite computer comprising the steps of: 1 adding one to a count NSIP in said central computer''s memory if a special interrupt count IC in MBXA does not equal NSIP, otherwise going to step (9),

Claim 41

In a data processing system comprising a central computer and at least one satellite computer interconnected by a communication channel, and a plurality of input and output terminals connected to said satellite computer, said central computer including a memory having a first area, MBXA, for storing control information and a plurality of other areas, each hereinafter referred to as a channel mailbox, utilized for communication between said central computer and said satellite computer, a method of operating said central computer to enable it to communicate with said satellite computer comprising the steps of: 1 adding one to a count NSIP in said central computer''s memory if a special interrupt count IC in MBXA does not equal NSIP, otherwise going to step (9),

Claim 42

storing the identity of said designated channel mailbox in MBXA,

Claim 43

storing the identity of said designated channel mailbox in MBXA,

Claim 44

A method as in claim 13 wherein step (17) comprises the steps of:

Claim 45

A method as in claim 14 wherein step (17) further comprises the steps of:

Claim 46

sending an interrupt signal to said satellite computer together with the identity of said designated channel mailbox,

Claim 47

sending an interrupt signal to said satellite computer together with the identity of said designated channel mailbox,

Claim 48

returning to step (1),

Claim 49

returning to step (1),

Claim 50

A method as in claim 15 wherein step (17) further comprises the steps of:

Claim 51

A method as in claim 16 further comprising the following steps in response to the presence of an entry in said first queue of an indication that a specified terminal is ready to send data:

Claim 52

performing certain operations in response to the presence of various operation codes in said designated channel mailbox,

Claim 53

performing certain operations in response to the presence of various operation codes in said designated channel mailbox,

Claim 54

clearing said designated channel mailbox of its contents,

Claim 55

clearing said designated channel mailbox of its contents,

Claim 56

A method as in claim 16 further comprising the following steps in response to the presence of an entry in said second queue of an indication that a specified terminal is ready to receive data:

Claim 57

A method as in claim 16 further comprising the following steps in response to a search request by a specified program:

Claim 58

returning to step (1) if NUASI 0, otherwise going to step (20),

Claim 59

returning to step (1) if NUASI 0, otherwise going to step (20),

Claim 60

subtracting one from NUASI,

Claim 61

subtracting one from NUASI,

Claim 62

returning to step (5), and

Claim 63

returning to step (5), and

Claim 64

terminating the operation.

Claim 65

terminating the operation.

Claim 66

storing an entry in a first queue indicating that the terminal specified in said designated channel mailbox is ready to send the data, in response to the presence of a third operation code in said designated channel mailbox,

Claim 67

storing an entry in a first queue indicating that the terminal specified in said designated channel mailbox is ready to send the data, in response to the presence of a third operation code in said designated channel mailbox,

Claim 68

going to step (18).

Claim 69

going to step (18).

Claim 70

storing an entry in a second queue indicating that the terminal specified in said designated channel mailbox is ready to receive data, in response to the presence of a fourth operation code in said designated channel mailbox,

Claim 71

storing an entry in a second queue indicating that the terminal specified in said designated channel mailbox is ready to receive data, in response to the presence of a fourth operation code in said designated channel mailbox,

Claim 72

going to step (18).

Claim 73

going to step (18).

Claim 74

searching an inquiry table for an indication that some program has made an inquiry, in response to the presence of a fourth operation code in said designated channel mailbox,

Claim 75

searching an inquiry table for an indication that some program has made an inquiry, in response to the presence of a fourth operation code in said designated channel mailbox,

Claim 76

storing in a location X of a certain program the identity of the terminal specified in said designated channel mailbox in response to an indication in said inquiry table that said certain program has made an inquiry,

Claim 77

storing in a location X of a certain program the identity of the terminal specified in said designated channel mailbox in response to an indication in said inquiry table that said certain program has made an inquiry,

Claim 78

storing in a table of line descriptions an indication that the terminal specified in said designated channel mailbox wishes to connect to a certain named program, in response to an indication in said inquiry table that no program has made an inquiry, and

Claim 79

storing in a table of line descriptions an indication that the terminal specified in said designated channel mailbox wishes to connect to a certain named program, in response to an indication in said inquiry table that no program has made an inquiry, and

Claim 80

going to step (18).

Claim 81

going to step (18).

Claim 82

selecting an available channel mailbox,

Claim 83

selecting an available channel mailbox,

Claim 84

storing in said selected channel mailbox a third command word, the identity of said specified terminal, and the address of the central computer''s memory where data is to be stored,

Claim 85

storing in said selected channel mailbox a third command word, the identity of said specified terminal, and the address of the central computer''s memory where data is to be stored,

Claim 86

storing the identity of said selected channel mailbox in MBXA, and

Claim 87

storing the identity of said selected channel mailbox in MBXA, and

Claim 88

sending an interrupt signal to said satellite computer together with the identity of said selected channel mailbox.

Claim 89

sending an interrupt signal to said satellite computer together with the identity of said selected channel mailbox.

Claim 90

selecting an available channel mailbox,

Claim 91

selecting an available channel mailbox,

Claim 92

storing in said selected channel mailbox a fourth command word, the identity of said specified terminal, and the address of said central computer''s memory from which data is to be retrieved,

Claim 93

storing in said selected channel mailbox a fourth command word, the identity of said specified terminal, and the address of said central computer''s memory from which data is to be retrieved,

Claim 94

storing the identity of said selected channel mailbox in MBXA, and

Claim 95

storing the identity of said selected channel mailbox in MBXA, and

Claim 96

sending an interrupt signal to said satellite computer together with the identity of said selected channel mailbox.

Claim 97

sending an interrupt signal to said satellite computer together with the identity of said selected channel mailbox.

Claim 98

searching said table of line descriptions for an indication of a terminal wishing to connect to said specified program,

Claim 99

searching said table of line descriptions for an indication of a terminal wishing to connect to said specified program,

Claim 100

storing in location X of said specified program the identity of a terminal specified in said table of line descriptions, if said searched for indication is obtained, otherwise going to step (42),

Claim 101

storing in location X of said specified program the identity of a terminal specified in said table of line descriptions, if said searched for indication is obtained, otherwise going to step (42),

Claim 102

going to step (45),

Claim 103

going to step (45),

Claim 104

storing an indication in said inquiry table that said specified program has made an inquiry,

Claim 105

storing an indication in said inquiry table that said specified program has made an inquiry,

Claim 106

delaying a certain predetermined period of time,

Claim 107

delaying a certain predetermined period of time,

Claim 108

going to step (45) if a terminal identity has been stored in location X of said specified program, otherwise returning to step (43),

Claim 109

going to step (45) if a terminal identity has been stored in location X of said specified program, otherwise returning to step (43),

Claim 110

transmitting data to or retrieving data from the terminal identified in location X of said specified program as the program desires.

Claim 111

transmitting data to or retrieving data from the terminal identified in location X of said specified program as the program desires.