Original Publication Date: 1978-May-01
Included in the Prior Art Database: 2005-Feb-20
An improved input/output (I/O) controller provides an optimized link between I/O devices and a computer system channel. In Fig. 1, I/O controllers (IOC) 20 are connected to system channel 15, which in turn connects to central processing unit (CPU) 10. Central processing unit 10 interfaces with main storage 5. I/O controllers 20 are physically identical, but can control different 1/0 devices, depending upon the I/O adapter connected and microcode executed by the particular IOC. Although it is not necessary for the IOC's to be so configured, the control storage for the microcode is implemented in read-only storage (ROS), and to facilitate commonality of the IOC's, the ROS is preferably part of the I/O adapters 70, which are connected between the IOC's 20 and I/O devices 80.