Midterm Exam,
Preliminary Terms and Concepts
Chapters 4, & 5 are very important, you should also be
familiar with concepts introduced in chapter 2 such as
multiprogramming, timesharing, batch.. etc. Select OS’s
from chapter 2 are listed because they introduce important
concepts still valid for today’s OS’s.
Your instructor’s lecture notes, and power point
presentations, are intended to augment your textbook,
not replace it.
Chapter 1: entire chapter: all sections.



What is an operating system.
What are the primary responsibilities of an OS.: supporting convenient use and
controlling sharing of resources,
Primary functions of an OS: User interface, process management, job and session
management, device management, time management, memory management, file
management, error handling, reliability and security, monitoring and accounting,
system management.
Review Questions to consider:
1 – 5, Assignment #3
Chapter 2: History of Operating systems:
Terms:
Process management
Process scheduling
Punched cards
Batch processing systems
interactive computing
Multi-tasking (timesharing)
Atlas OS
Input/Output System
CTSS
CP/M
interleaved execution multiprogramming
device management
interrupts
resident monitor/loader
JCL
batch serial operation
batch multiprogramming
time quantum/time slicing
device driver
command line interface
OS 360
Unix
Share OS
MCP
RT11
RSTS
Concepts:
all sections. You should understand the major types of operating systems, how operating
systems evolved, why they evolved, features of the different CATAGORIES of operating
systems. How did punched cards, magnetic tapes, JCL, magnetic disks, and
professional operators revolutionize computing, and how did they help lead to the
evolution of operating systems. Know the importance of the “resident loader” (resident
monitor). Understand the concepts of multiprogramming, spooling, and multitasking.
What is meant by BATCH computing? What is a batch operating system.
Questions to consider:
1-7, Assignment questions: 3,
Instructors Notes:
Lecture notes & power point slides from instructor with information from additional
sources.
Chapter 4: process management:
Terms:
Sequential process
Thread
Context
Batch processes
Preemption
Job
concurrent sequential processes
process control block (PCB)
processor state
context switching
interactive processes
real-time processes
fork
ready queue
SCHEDULING
scheduler
Concepts:
entire chapter!!! - very important chapter-- You must understand what is a process,
and what are the different types of processes and what are their characteristics. It is
important to understand what it means to execute processes in an interleaved fashion.
What is the role of the PCB? What is the context of a process? Understand what is a
process state. What are the different process states? What causes a transition from one
state to another.. focus on diagram 4-4. Be able to draw a state chart and explain it!!! Be
able to discuss the various operations that can be performed on processes, and what they
involve (especially creation and termination).
Questions to consider:
1 - 10
Instructors Notes:
Lecture notes & power point slides from instructor with information from additional
sources.
Chapter 5 – process scheduling
Terms
Long term scheduling short term scheduling medium term scheduling
Active set
swapping
dispatcher
Process states
waiting time
response time
Preemption
FIFO scheduling
Dynamic priority scheduling
Preemptive scheduling
shortest remaining time next
Time quantum
processor time quantum
storage time quantum
Round robin scheduling
aging
feedback queues
CPU bound processes
I/O bound processes
selfish scheduling
Active set
dispatcher
priorities
Static priority algorithms
dynamic priority algorithms starvation
Concepts:
Process scheduling: !!!! entire chapter, very important!!!!! --- Know the 3 types of
scheduling that can be performed and what each type of scheduling accomplishes. (longterm, short-term, medium-term), know the types of scheduling which must occur in the 3
major types of operating systems (real-time, batch, and interactive). Know the scheduling
objectives that are often used in the evaluation of scheduling algorithms. Why is
calculating the average waiting time important in assessing an algorithm. Understand
the concept of aging!!! Understand what it means for a process to be CPU bound .vs.
I/O bound. BE ABLE TO EXPLAIN, EACH OF THE FOLLOWING
SCHEDULING ALGORITHMS. Also be able to estimate the average waiting time for
a set of processes.. FIFO, shortest job next, shortest time remaining next, round
robin (fifo), priority round robin, feed back queues, static priority
Questions to review in your text book:
1,2, 3, 4, 7, 8 & 9
Instructors Notes:
1. Notes on Process scheduling: Additional information and terms have been added
from other sources . This source adds additional information on I/o vs cpu bound
processes, as well as additional objectives of scheduling algorithms
2. Notes on scheduling algorithms: Additional information and terms have been
added from other sources This contains additional details about the various
scheduling algorithms, and gives examples of calculating the average waiting time of
processes.
see you instructors lecture notes & power point presentation
Chapter 6 – Interrupts
Terms:
Interrupt
Interrupt handler
Interrupt Vector
Concepts:
1. KNOW THE ISSUES INVOLVED IN HANDLING INTERRUPTS:
1. SAVING THE STATE
2. LINKING TO THE INTERRUPT
3. HANDLING PARAMETERS
4. RESOURCE USE AND PROCEDURE CALLS
5. HANDLING OTHER INTERRUPTS
2. Understand how interrupts affect the flow of control within a program
3. Know the different categories of interrupts: i/O, alert, timer, machine faults,
system request interrupts, program fault interrupts.
Questions to review:
Review: 1- 3 Assignment #5
Instructors notes / slides:
Power point slides on Interrupts.