Open I/O Architecture for a High-Level Computer System
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
The IBM System/38 high-level machine architecture provides a machine interface which is largely independent of hardware details. Hardware dependencies are absorbed by internal microcode functions that handle many machine dependencies including channel and I/O interface details. The advantages of high-level machine architecture include integrity, security and ease-of-use. The cost of providing such an architecture is, with respect to I/O, that the manufacturer must provide special microcode to include each I/O device in the machine interface. The effect is to close the machine interface to all but the I/O devices selected by the manufacturer; usually those popular devices most likely to be selected by many customers.