 Chapter 1
Gates and the logical operations they perform
Powers of two
and
2
0
1
21
2
2
2
4
23
8
24
16
2
5
32
26
64
27
128
2
8
256
29
512
Powers of ten
210 1024 = 1K = 1 kilo approximately 103 1 thousand 1,000
Memory cells arranged by address
Decoding the binary representation 100101
Decoding the binary representation 101.101
An algorithm for finding the binary representation of a positive integer
Binary
Addition
+
0
0
0
+
1
0
1
+
0
1
1
+
1
1
10 Note: if the
result can only
hold one bit then
this would cause
an overflow
error
 Chapter 2
- Von Neumann Architecture Model
-
Roles of memory, CPU(control unit, ALU, Registers), Bus, I/O (Page 80)
-
Decoding of instructions
-
Translation of instructions
-
Machine cycle (Control unit performs its job)
Homework, quiz2 and slides are also a good review.
 Chapter 3
Some functions of an operating system
• Oversee operation of computer
• Store and retrieve files
• Schedule programs for execution
• Execute programs
Types of software
• Application software
– perform specific tasks for users
• System software
– perform tasks needed by all computer systems
– Operating system
– Utility software
Components of an operating system
•Shell: portion that communicates with users
–Graphical user interface (GUI)
•Window manager
•Kernel: contains components performing basic required functions
–File manager
–Device drivers
–Memory manager
–Scheduler and dispatcher
File Manager
• Directory or folder: user-created group or bundle of files
• Path: position of a file in directory hierarchy
• File descriptor: information needed to access an open file
Startup the machine (bootstrapping)
• Bootstrap: program in read only memory (ROM)
– Run by the CPU when power is turned on
– Transfers operating system from mass storage to main memory
– Executes jump to operating system
Processes
• Program = a static set of directions
• Process = the dynamic activity of executing a program
• Process state = current status of the activity
– Snapshot of relevant parts of the machine state
– Program counter, other registers, associated main memory
Process administration
• Scheduler
– Keeps state of all processes in an process table
• Ready or waiting
• Priority
• Non-scheduling information: memory pages, etc.
•Dispatcher
– Gives one time slice or quantum to a process that is ready
– Executes a process switch (or context switch) when the running process’s time
slice is over
• Interrupt indicates that time slice is over
• Interrupt handler: part of dispatcher
 Chapter 4
Network classification
• Local area network (LAN)
• Wide area network (WAN)
• Closed, or proprietary
• Open
Network topology
• Bus
• Ring
• Star
Distributed system
• Client-server
• Peer-to-peer
Internet
• Domain = network or internet controlled by one organization. Their owners must
register the domain.
cloud = the rest of the internet
Internet Corporation for Assigned Names & Numbers (ICANN) serves as registrar
Domain name = part assigned by a registrar
• Internet Protocol (IP) address
32 bit identifier for a machine
Network identifier = part assigned by ICANN
Host address = part assigned by domain owner
Dotted decimal notation = standard for displaying IP addresses
Example: 216.239.59.147
 TERMS
Chapter 1
Term
Descriptive Phrase
bit
Binary digit
Binary notation
Uses bits to represent a number in base two
Boolean operation
AND, OR, XOR, NOT
address
A numeric value used to identify a memory cell
hexadecimal notation An efficient way of representing bit patterns a shorthand notation
for streams of bits
file
The unit of data stored on a mass storage system
Logical record and Field
Natural groups of data within a file
Physical record
A block of data conforming to the physical characteristics of the
storage device
sector
A segment of a track in a mass storage system
buffer
A storage area used to hold data on a temporary basis, often as a
step in transferring the data from one device to another
ISO
An international organization for establishing standards
ANSI
A major standardization organization within the United States
ASCII
A system developed by the American Standards Institute for
encoding text
flip-flop
A digital circuit capable of holding a single digit
two’s complement notation
A means of encoding signed integers where the left
most bit = 1 when the integer is negative
floating-point notation
A means of encoding numeric values that may involve
fractions
truncation
An error that may occur when using floating-point notation
Gates
Devices that produce the outputs of Boolean operations when
given the operations’ input values
Dynamic memory
Must be replenished periodically – Example: capacitors
Volatile memory
Holds its value until the power is turned off – Example: flipflops
Non-volatile memory
Holds its value after the power is off – Example: magnetic
storage
Read-only memory (ROM)
Never changes – Examples: flash memory, compact
disks
Cells
Manageable units (typically 8 bits) into which a computer’s
main memory is arranged.
Byte
A string of 8 bits
High-order end
The left end of the conceptual row in which the contents of a
cell are laid out
Low-order end
The right end of the conceptual row in which the contents of a
cell are laid out
Least significant bit
The last bit at the low-order end
NOR operation
An OR followed by a NOT
Chapter 2
Term
Descriptive Phrase
op-code
The part of a machine instruction that identifies the basic
operation to be performed
machine instruction
An instruction coded as a bit pattern directly recognizable by
the CPU
machine language
A means of encoding instructions
machine cycle
The process of fetching and executing instructions that is
repeated over and over by the CPU
register
A location within a CPU for temporary data storage
masking
A means of isolating particular bits within a bit pattern
bus
The communication path between a CPU and main memory
memory-mapped I/O
The technique of communicating with peripheral devices as
though they were memory cells
pipeling
A means of processing more than one instruction at a time
stored-program concept
A technique of recording programs in main memory from
where they can be accessed and executed
program counter
Used by the CPU to keep its place in the program being
executed main memory from where they can be retrieved and executed
controller
The interface between “a computer” and a peripheral device
modem
Modulator-demodulator
port
The collection of “addresses” by which a CPU
communicates with a peripheral device
clock
Used to synchronize the operations within a computer
status word
A means by which a peripheral device reports its condition
bps
A means of measuring the rate of data transfer
CISC
A computer whose machine language contains many
complex instructions
handshaking
Refers to the two-way communication that takes place
between a computer an a peripheral device
bandwidth
Refers to a communication path’s maximum capacity for
transferring data
DMA
The ability of a peripheral device to communicate directly
with a computer’s main memory
Data communication path types:
Serial: one line transfers one bit at a time
Parallel: several lines transfer different bits simultaneously
Modem: converts between digital bits and analog tones
Technologies to increase throughput
Pipelining: overlap steps of the machine cycle
Parallel processing: use multiple processors simultaneously
Chapter 3
Term
Descriptive Phrase
shell
The part of an operating system that communicates with the user
time sharing
A technique that allows multiprocessing on a computer with a
single CPU
process
The activity of executing a program
queue
A storage system in which the first entry in is the first entry out
virtual memory
Extended storage space created by the memory manager
ROM
Memory area whose contents cannot be altered
multitasking
The act of performing more than one activity at the same time
interactive processing
Allows the user to communicate with the computer system
while the user’s application is being performed
deadlock
A situation in which activities find themselves waiting on each
other
worm
An software infection that spreads itself from one machine to
another
GUI
A means of communicating with a computer user by means of
images rather than words
mutual exclusion
Requiring that a process complete a block of instructions before
another process is allowed to start the block
bootstrap
The program first executed when a computer is turned on
directory path
A sequence of folders each containing the next
kernel
The heart of an operating system
interrupt
A signal that suspends the CPU’s current activities
Chapter 4
Term
internet
domain
protocol
cloud
IP address
HTML
Descriptive Phrase
A network of networks
A portion of the Internet
A governing set of rules
The portion of the Internet lying outside one’s domain
Identifies a machine on the Internet
A notational system for indicating how a Web document is to be
displayed by a browser
ISP
A means of obtaining access to the Internet
firewall
A means of blocking undesired messages
packet
A message segment that is transmitted over the Internet independently
FTP
A protocol for transferring files
router
A means of connecting networks to form an internet
dotted decimal
A notational system for representing bit patterns
URL
A means of identifying a document on the Web
search engine
A means of finding relevant information on the Web
Ethernet
A means of implementing a network with the bus topology
UDP
A protocol for the transport layer
IP
A protocol for the network layer