University of Rhode Island DigitalCommons@URI Open Access Master's Theses 1978 A Virtualizable MAchine for Multiprogrammed Operation Based on Non-Virtualizable Microprocessors William D. Armitage University of Rhode Island Follow this and additional works at: https://digitalcommons.uri.edu/theses Recommended Citation Armitage, William D., "A Virtualizable MAchine for Multiprogrammed Operation Based on Non-Virtualizable Microprocessors" (1978). Open Access Master's Theses. Paper 1390. https://digitalcommons.uri.edu/theses/1390 This Thesis is brought to you for free and open access by DigitalCommons@URI. It has been accepted for inclusion in Open Access Master's Theses by an authorized administrator of DigitalCommons@URI. For more information, please contact
[email protected]. A VIRTUALIZABLE MACHINE FOR MULTIPROGRAMMED OPERATION BASED ON NON-VIRTUALIZABLE MICROPROCESSORS BY WILLIAM D. ARMITAGE A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN COMPUTER SCIENCE UNIVERSITY OF RHODE ISLAND 1978 MASTER OF SCIENCE THESIS OF WILLIAM D. ARMITAGE Approved: Thesis Committee AI Maj or Professor J ~~~~~~~~~~~~~~~~~-v.tfsc'YI WeA·cfuul/l ev\,~ . ~cL a . L~ Ct-actc=<A.- Dean of the Graduate School UNIVERSITY OF RHODE ISLAND 1978 ABSTRACT Microcomputers are proliferating in d ed ic ated applications and as single-user general-purpose digital computers. Many common applications on larger machines are inherently multi-user and require a multiprogrammed mode of operation. Multiprogrammed operating systems, although desirable for this reason and to maximize utilization of expensive system components, have not yet been satisfactorily implemented on m ic rocom put er s. It is shown that a typical microprocessor -- the Intel 8080 is inherently incapable of supporting a multiprogrammed operating system due to a lack of any privileged instruction set whatsoever.