In this article Fu-Manchu discusses MINIX, a computer operating system that is a free download via the Internet unencumbered by restrictive licensing. MINIX is so called because it is a mini version of UNIX that will run on any Intel CPU¹ architecture, from the Intel 8088 onwards. Also, we discover why this might be of interest to a personal computer user, especially if that person has old equipment gathering dust in a cupboard, as most long-term computer users probably do.

A Brief History

English mathematician Charles Babbage (1792-1871) conceived the first computing machine, which he proposed to the Navy Board for automatic computation of the numerical tables used in the solution of navigation problems. He never delivered on his promise because of problems with the mechanical construction of the engine and with his own fertile imagination that kept finding improvements that required radical changes to the design. He describes his tribulations in his 1864 book Passages from the Life of a Philosopher.

Charles Babbage also discovered software whilst on a visit to France to see the workings of the power loom used by Joseph Marie Jacquard (1752-1834), controlled by punched cards. Immediately, Babbage saw the possibilities for his analytical engines when programmed by a similar system of punched cards.

Babbage’s was a failure to understand that success is achieved by quickly delivering a working machine to get the customer hooked on the convenience. Having done so, the next step is to sell a series of enhancements to the machinery. Babbage was a scientific engineer not a marketeer. Compare the difference between Charles Babbage and Bill Gates: Babbage had a mind that was a sparkling fount of innovative ideas whereas Gates is just the richest man in the world.

Electronic Computers

Computer operating systems have evolved from first generation electronic calculating engines that used valve technology (vacuum tubes). These computers were programmed by changing the arrangement of a plugboard, similar to those found on a very early telephone operator’s console. Systems such as these date from the decade beginning at the end of the second world war in 1945.

Second generation computers were constructed from the new invented transistor logic and programmed by batches of punched cards. Transistor technology enabled a reduction in size of computers, but still required special machine rooms to house the equipment.

In another decade discrete transistors were replaced by integrated circuits, which gave rise to third generation computers capable of multiprogramming. By this time IBM was the computing Goliath in the world. A key invention of the time was the MULTICS² operating system that allowed many users to share time on a single machine.

During the third computer generation minicomputers became popular, epitomized by the DEC³ PDP⁴ series that culminated in the PDP-11. Ken Thompson, who had worked on MULTICS, found a spare PDP-7 and wrote a single user version of MULTICS that later developed into the UNIX⁵ operating system. UNIX became very popular in the computing community, in many incompatible varieties. Because of these incompatibilities, the IEEE⁶ developed a standard for UNIX called POSIX⁷ to foster application code compatibility running on the different varieties of POSIX compliant UNIX operating systems.

Since 1980, large-scale integrated circuits have made possible the fourth generation of computers that we see on our desks and in our laps. High power workstations were dominated by the UNIX operating system. Microsoft Corporation’s MSDOS⁸ and WINDOWS grew to dominate the personal computer market.

MINIX

First six versions of UNIX were widely available and much studied in university departments of computer science. With version 7, AT&T⁹ imposed a license that drew a veil over the source code to protect its status as a trade secret, preventing study of UNIX. A professor of Computer Science, Andrew S. Tanenbaum, believes that operating system theory without practice is a bad thing. To remedy this defect, he decided to write a new operating system that would be compatible with UNIX from the user's point of view, but completely different on the inside. By avoiding use of AT&T code, this system avoids licensing restrictions.

Tanenbaum's new operating system is called Mini UNIX, more usually just MINIX, because it is small enough that even a beginner can understand how it works. In its original version, MINIX was designed to run on the Intel architecture found in IBM PCs, since then it has been ported to run on Atari, Amiga, Macintosh, and SPARC¹⁰ computers.

LINUX

MINIX became popular among the students of computer science and hobbyists of many types. Eager users directed to Andrew S Tanenbaum a steady stream of requests to expand the system; all of which Tanenbaum resisted because he wanted to keep the mini in MINIX so that it would continue to be easy to understand.

Finally, Linus Torvalds wrote his own operating system based on MINIX and released it to the computing community as LINUX. An enthusiastic reception of LINUX has turned it into the product it is today, freely available and wholly open to expansion. At time of this writing, it is also under attack by the dark forces of SCO¹¹ who claim that LINUX includes intellectual property that belongs to SCO¹².

Why Use MINIX

Software is now so bloated and packed with features, some rarely used, that the Microsoft Windows operating system cannot be installed on early machinery; neither can LINUX. Fu-Manchu attempted to install the Debian distribution of LINUX on and old Toshiba 386DX machine equipped with 8 Mbytes of memory and a 100 Mbyte HDD¹³ and failed because the most basic system requires 12 Mbytes of memory and 125 Mybtes of HDD.

Of course, it is possible to squeeze LINUX into a machine with these resources. Problem is you must be adept with the OS¹⁴ to do this. An easier option is to install MINIX, which only requires 30 Mbytes of HDD and and a paltry 4 Mbytes of main memory.

Question in the mind of the reader who has read this far is: ‘Why bother?’ MINIX is not for the casual user of computers, neither is UNIX, both of which are command-line systems that require the user to issue commands one line at a time; unlike MicroSoft WINDOWS that usually has a graphical user interface on which the user points and clicks with a mouse. MINIX is an excellent OS for learning about the workings of Operating Systems in general. Because MINIX is a learning tool, it is well documented and is supplied with the source code files for the entire system, source code that is well commented so that a persistent novice can learn the workings of the system. With MINIX there is the potential for a user to modify the workings of the system to suit some new requirement, something that cannot be done with a closed system like MicroSoft WINDOWS. MINIX enables resurrection of obsolete hardware to useful purpose. Old hardware can be redeployed in networked computing clusters. MINIX puts the hobbyist in closer control of the computer.

Getting MINIX

MINIX is available via the Internet. Start here at the MINIX Home Page.

Instructions necessary to install MINIX are available here in the Guide.