That portion of a unit control block that contains a drive ' s context while the driver is waiting for a resource 单元控制块的那一部分,该部分包括驱动程序上下文,而驱动程序正在等待资源。
An area of main storage that holds the addresses of the unit control blocks and system control blocks for each symbolic unit 主存储器中存放每个符号设备的设备控制块和系统控制块的地址的一种区域。
In IBM mainframe operating systems from the OS/360 and successors line, a Unit Control Block (UCB) is a memory structure, or a control block, that describes any single input/output peripheral device (unit), or an exposure (alias), to the operating system. Certain data within the UCB also instructs the Input/Output Supervisor (IOS) to use certain closed subroutines in addition to normal IOS processing for additional physical device control.