Homework 1
                          Chapter 1

1.  What are the two main functions of an operating system?

2.  What is multiprogramming?

3.  What is spooling?  Do you think that advanced personal
computers will have spooling a standard feature in the
future?

4.  On early computers, every byte of data read or written
was directly handled by the CPU (i.e., there was no DMA--
Direct memory Access).  What implications does this organization
have for multiprogramming?

5.  Why was timesharing not widesread on second-generation 
computers?

6.  Which of the following instructions should be allowed
only in kernel mode?

    (a)  Disable all interrupts.
    (b)  Read the time -of-day clock.
    (c)  Set the time-of-day clock.
    (d)  Change the memory map.

7.  List some differences between personal computer operating
systems and mainframe operating systems.

8.  A MINIX (or UNIX) file whose owner has uid = 12 and
gid = 1 has mode rwxr-x---.  Another user with uid = 6
and gid = 1 tries to execute the file.  What will happen?

9.  In view of the fact that the mere existence of a super-user
can lead to all kinds of security problems, why does such
a concept exist?

10.  The client-server model is popular in distributed systems.
Can it also be used in a single-computer system?

11.  Why is the process table needed in a time-sharing system?
Is it also needed in a personal computer system in which
only one process exists, that process taking over the entire
machine until it is finished?

12.  What is the essential difference between a block special
file and a character special file?

Due:  25 Feb 98

email to:  yxie1@umbc.edu