Software Communication of Device Command Attributes
Original Publication Date: 1980-Nov-01
Included in the Prior Art Database: 2005-Feb-14
In existing system control programs, there is no way for the program to determine whether a device will accept certain channel command words (CCWs), or to determine certain device characteristics of those CCWs which are accepted. This causes programmers to write device-dependent software to support new devices. It also causes a potential for software bugs as functions are added or changed in devices or device-dependent software. Thus, device-dependent programs often will include a command attribute table for each device in every program that does translation or analysis of CCW sequences. A typical example of this support is the manner in which CCWs are translated by operating systems. There are many attributes of devices and their control units not apparent to the software.