What parts of the book have changed since the 1st edition?
The book contains two kinds of material: principles of operating systems and a discussion about MINIX. The principles part has been brought up to date, but is quite recognizable from the first edition. The MINIX part is very different from what it was.
Why is the MINIX part so different?
In 1987, MINIX 1.0 came out as an operating system to demonstrate that you could run something approaching UNIX on a 4.77 MhZ PC with 256 KB RAM, one 360 KB floppy disk, and no hard disk. Since then it has grown into a full-fledged 32-bit operating system, although a 16-bit version can still be compiled and run on 8088s and 286s. All the changes in MINIX itself have necessitated a major rewrite of that part of the book discussing MINIX.
What are the major changes to MINIX 2.0 compared to MINIX 1.0?
There are many. A few of them are:
- It now runs well on machines ranging from the 8088 to Pentium Pro
- A wide range of peripheral devices are supported
- On 386s and above it runs in 32-bit protected mode
- The file system can now handle gigabyte disks
- TCP/IP networking has been added for Ethernets
- Every copy of the OSDI book contains a CD-ROM with all of MINIX
- Minix 2.0 is a modern POSIX-compliant system; Mini 1.0 resembled the 7th Edition UNIX of the early 1980s
Does MINIX run on other platforms than Intel?
Version 2.0, which is described in the book, currently runs native on only the Intel CPUs (but all of them from the 8088 up). An earlier version, MINIX 1.5, also ran on the Macintosh, Atari, Amiga, and SPARC, but the current version has not yet been ported.
If I don't have an Intel-based computer, am I out of luck?
No. We thought of that. The MINIX distribution comes with TWO simulators. One of them allows MINIX to run as a user program on a SPARC workstation. This version only works on SPARCS, but it runs MINIX at full speed. The other simulator is a 386 interpreter that can run MINIX on the bare (interpreted) hardware. Of course, running MINIX on an interpreted 386 is slower than running it on the bare metal, but it is still quite usable. This simulator works on any computer that supports X Windows. Both simulators are on the CD-ROM.
Is MINIX also available for free via the Internet?
Yes. Just click here to get it. The full CD-ROM image is available on the net, including both simulators.
How would you compare MINIX and Linux?
From the very beginning, MINIX has been designed as a system for teaching students and others about operating systems. An overriding concern has always been to keep it simple enough for people to understand. In particular, it is still simple enough that the complete core of the source code is listed in the book and can be understood by a student in a one semester course. Linux was designed as a production system and is correspondingly much less suited to learning about operating systems.
What is the structure of MINIX?
MINIX is still a microkernel, like modern systems such as Mach, Chorus, and Amoeba, and unlike older systems such as UNIX, Linux, and MS-DOS. It was, in fact, one of the first microkernel-based systems. The memory manager and file system run as user processes in MINIX, making the kernel much simple and easier to understand. As a byproduct of this simple design, MINIX is actually quite fast as well.
Getting back to the principles part of the book, what has changed there?
There is new material on interprocess communication and more examples, new scheduling algorithms are covered (e.g., real time), modern ideas about virtual memory are covered, new paging algorithms are described, and so on. New exercises have been added corresponding to the new material. All in all, the changes to the principles are relative modest.
Are there any new teaching aids?
Yes. In addition to the solution manual for instructors, all the figures in the book can be obtained by ftp over the Internet, in the form of PostScript files which can be used to produce transparencies.
In summary, what are the strengths of the Second Edition?
This book remains the only operating systems book that covers all the standard principles and shows how they are applied to a real system by discussing the actual source code file by file. The MINIX source code is still listed in an appendix in the book (minus some of the more exotic device drivers) so it can be consulted as you read the book. No other operating systems book describes a real system you can actually use in anything like this level of detail.
|© 1997 Prentice Hall
Prentice Hall, Inc.
A Simon & Schuster Company
Upper Saddle River, New Jersey 07458