公开(公告)号：DE1282335B

公开(公告)日：1968-11-07

申请号：DEJ0030052

申请日：1966-02-12

Applicant: IBM

Inventor： BEAUSOLEIL WILLIAM FRANCIS ,  D ANTIBES LE CAP ,  HOSKINSON WILLIAM CLIFFORD ,  KING LEWIS EDARD ,  O HERBERT GERHARD WELBER

IPC: G06F13/10 ,  G06F13/12 ,  G06F15/16 ,  G06F15/17 ,  G06F15/177

Abstract: 1,119,421. Data processors. INTERNATIONAL BUSINESS MACHINES CORP. 18 Jan., 1966 [16 Feb., 1965], No. 2228/66. Heading G4A. Data is transmitted between two data processing devices via a buffer adapter linked to both devices by data and control channels, which also link the data processing devices to respective groups of input/output devices. Two or more computers are linked together and to input-output (I-O) control units (each controlling one or more input-output devices) by one or more adapters. The channels linking a computer to an adapter comprise a 9-wire data channel (8 bits plus 1 parity bit) from the computer (" bus out "), a similar channel to the computer (" bus in "), tag lines in and out indicating the type of information on the associated bus (e.g. data, address, command, status), various interlock lines, a loop enabling the I-O control units to be scanned in turn, and a suppress out line for preventing presentation of status information or data to the computer. When a first computer (any one) requires to send data to a second computer (any other) it sends the address of the appropriate adapter (priority between adapters is also mentioned) which responds by raising an interlock line to the first computer. The latter drops the address signals whereupon the adapter returns the address to the computer which then sends a write command to the adapter. The adapter attempts to interrupt the second computer. The latter, when ready, issues a sense command to the adapter which in response supplies to the second computer, the (write) command from the first (which was stored in the adapter). The second computer generates a read command and the adapter supplies status information to the first. A comparison is made in the adapter to assure that both computers are not executing the same command. Provided they are not, the adapter signals for successive bytes of data from the first computer and transfers them via a buffer to the second computer. When all the data has been transferred, the first computer issues a stop command to the adapter which generates a status signal and then disconnects from both computers whereupon the latter proceed to scan their respective I-O control units independently. If the comparison (see above) had indicated the same command was being executed, an appropriate status signal would be provided to the initiating computer and the adapter would disconnect. A test I/O command can be used to determine the status of the adapter.