NACHOS (Appendix to "OPERATING SYSTEM CONCEPTS, FOURTH 
EDITION, ISBN 0-201-50480-4, Copyright Addison-Wesley 
Publishing Company, Inc., 1994)

by Thomas Anderson, University of California, Berkeley

Nachos is written in a very simplified subset of C++. The 
distribution of Nachos comes with a 10 page primer to help 
C programmers learn the C++ subset; we find normal C 
programmers can pick up our subset of C++ in a couple of 
days.


Obtaining a Copy of Nachos

Nachos can be obtained by anonymous ftp from the machine
"ftp.cs.berkeley.edu" by following these steps:

1. Use UNIX ftp to access ftp.cs.berkeley.edu:
      ftp ftp.cs.berkeley.edu

2. You will get a login prompt. Type the word "anonymous," 
   and then use your email address as the password.

      Name:   anonymous
      Password: [your e-mail address]

3. You are now in ftp. Move to the Nachos sub-directory.
   At the "ftp>" prompt, type:
      cd ucb/nachos

4. You must remember to turn on "binary" mode in ftp; 
   unfortunately, if you forget to do this, when you fetch 
   the Nachos file, it will be garbled without any kind of 
   warning message. This is one of the most common errors 
   in obtaining software using anonymous ftp.

   At the "ftp>" prompt, type
      set binary

5. You can now copy the compressed UNIX tar file containing 
   the Nachos distribution to your machine. The software 
   will automatically enroll you onto a mailing list for 
   announcements of new releases of Nachos. You can remove 
   yourself from this list by sending email to 
      nachos@cs.berkeley.edu.
   In the meantime, to actually get the file, at the "ftp>"
   prompt, type:
      get nachos.tar.Z

6. Exit the ftp program:
   Type:
      quit

7. Decompress and detar to obtain the Nachos distribution. 
   (If the decompress step fails, you probably forgot to 
   set binary mode in ftp in Step 4. You will need to start 
   over.)
      uncompress nachos.tar.Z
      tar -xf nachos.tar

8. The preceding steps will produce several files, 
   including the code for the baseline Nachos kernel, the 
   hardware simulator, documentation on the sample 
   assignments, and the C++ primer. There will also be a
   README file to get you started: it explains how to build 
   the baseline system, how to print out documentation, and 
   which machine architectures are currently supported.

Questions about Nachos and bug reports should be directed 
via email to:
   nachos@cs.berkeley.edu.

Questions can also be posted to the alt.os.nachos 
newsgroup.