Technique for Dynamic Allocation of Input/Output CONTROL Blocks to an Input/Output DEVICE
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
This article describes a method for use in the input/output (I/O) subsystem of a data processing system that provides for dynamic allocation of I/O control blocks always synchronized with the processor program. (Image Omitted) Fig. 1 illustrates a representative set of essential I/O command parameters for starting an I/O operation. The sizes of fields chosen for the illustration is arbitrary. The parameters are: e 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 specified device on the appropriate I/O bus by the processor program.