Not Another Completely Heuristic Operating System
Encyclopedia
Not Another Completely Heuristic Operating System, or Nachos, is instructional software for teaching undergraduate, and potentially graduate level operating systems courses. It was developed at the University of California, Berkeley
, designed by Thomas Anderson, and is used by numerous schools.
Originally written in C++
for MIPS
, Nachos runs as a user-process on a host operating system. A MIPS simulator executes the code for any user programs running on top of the Nachos operating system. Ports of the Nachos code exist for a variety of architectures.
In addition to the Nachos code, a number of assignments are provided with the Nachos system. The goal of Nachos is to introduce students to concepts in operating system design and implementation by requiring them to implement significant pieces of functionality within the Nachos system.
Nachos version 3.4 has been the stable, commonly used version of Nachos for many years. Nachos version 4.0 has existed as a beta since approximately 1996.
created Pintos
, a Nachos-inspired system written in C
and designed to run on actual x86 hardware. In 2000, Dan Hettena at UC Berkeley ported Nachos to Java
as Nachos 5.0j, in an effort to make Nachos more portable, more accessible to undergraduates, and less susceptible to subtle bugs in student code that had in earlier versions often dominated student project development time. Another Java-based version was created by Professor Peter Druschel at Rice University
. It was later adapted by Professor Eugene Stark at Stony Brook University in 2003 and applied in the Operating System
course. At Graz University of Technology
(Austria), a system called SWEB ("Schon wieder ein Betriebssystem") has been implemented and is used to teach operating system principles.
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
, designed by Thomas Anderson, and is used by numerous schools.
Originally written in C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...
for MIPS
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...
, Nachos runs as a user-process on a host operating system. A MIPS simulator executes the code for any user programs running on top of the Nachos operating system. Ports of the Nachos code exist for a variety of architectures.
In addition to the Nachos code, a number of assignments are provided with the Nachos system. The goal of Nachos is to introduce students to concepts in operating system design and implementation by requiring them to implement significant pieces of functionality within the Nachos system.
Nachos version 3.4 has been the stable, commonly used version of Nachos for many years. Nachos version 4.0 has existed as a beta since approximately 1996.
Successors
As Nachos has not been in active development for a number of years, and possesses a number of recognized flaws (particularly with regards to portability: Nachos relies on MIPS assembly code, and requires porting to run on x86 architecture), successor projects have been initiated. In 2004, Stanford UniversityStanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
created Pintos
Pintos
Pintos is a simple instructional operating system framework for the 80x86 architecture. The software supports kernel threads, loading and running user programs, and a file system, but it implements all of these in a very simple way. Pin created at Stanford University by Ben Pfaff in 2004...
, a Nachos-inspired system written in C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
and designed to run on actual x86 hardware. In 2000, Dan Hettena at UC Berkeley ported Nachos to Java
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
as Nachos 5.0j, in an effort to make Nachos more portable, more accessible to undergraduates, and less susceptible to subtle bugs in student code that had in earlier versions often dominated student project development time. Another Java-based version was created by Professor Peter Druschel at Rice University
Rice University
William Marsh Rice University, commonly referred to as Rice University or Rice, is a private research university located on a heavily wooded campus in Houston, Texas, United States...
. It was later adapted by Professor Eugene Stark at Stony Brook University in 2003 and applied in the Operating System
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
course. At Graz University of Technology
Graz University of Technology
The Graz University of Technology is the second largest university in Styria, Austria, after the University of Graz. Austria has three universities of technology – in Graz, in Leoben, and in Vienna. The Graz University of Technology was founded in 1811 by Archduke John of Austria. TUG, as the...
(Austria), a system called SWEB ("Schon wieder ein Betriebssystem") has been implemented and is used to teach operating system principles.