Input/Output Control Block Restart Command
Original Publication Date: 1987-Jan-01
Included in the Prior Art Database: 2005-Jan-31
This article describes a technique for use in the input/output (I/O) subsystem of a data processing system which eliminates the necessity for I/O devices to refetch control blocks for restarting an I/O operation. The command that normally initiates an I/O operation is a Start command. The drawing illustrates a representative set of essential I/O command parameters for starting an I/O operation. The size of fields chosen for the illustration is arbitrary. The parameters are: The command byte . The I/O address, specifying the address of the target device. . A storage address, pointing to an I/O control block (IOCB) in the main storage of the processor. These parameters are passed to the I/O device on the appropriate I/O bus by the processor program.