Alessandro Forin, David Golub, Brian Bershad. An I/O System for Mach. [postscript]. Proceedings of the Usenix Mach Symposium, November 1991.

The Mach 3.0 I/O system represents a radical departure from its predecessor-Mach 2.5, which relied on the BSD Unix model of device management. The I/O interface in Mach 3.0 supports device drivers that are largely device-independent, implemented at user-level, and location-independent. Our approach to device management significantly reduces the size of the kernel's machine-dependent code, enables us to reduce the length of the I/O path, and permits us transparently manage remote devices on non-shared memory multiprocessor architectures such as the Hypercube. This paper describes the structure and performance of Mach's I/O system.