I/O device Emulation in The Stanford Emulation Laboratory

Abstract

This report describes the implementation of an I/O device emulation system for a universal host machine, the Emmy. The actual system I/O devices are part of a PDP-11/05 system supporting the UNIX operating system. To support device emulation a process is established within this system to act as a simple I/O channel responding to host I/O requests. This channel process is able to provide three basic device structures: serial, linear and variable, which correspond roughly to character, disk-like and tape-like devices respectively. These structures have been found to be adequate for a wide range of system emulations. Examples of such systems and their performance are given.