Comp1004 Winter 2016
Carleton University
By Andrew Runka
With notes from Dr. Irwin Reichstein

Memory Aids
 Finger Counting
 Counting stones, Tally sticks, Counting rods, etc
 Abaci

Fixed Program Devices
 Antikythera Mechanism (c. 205-100 BCE)
 Various clockwork mechanisms
 Slide rules (c. 1600s) to modern calculators
 Difference Engine (c. 1800s)

General purpose computers
 Analytical Engine (c. 1837)
▪ Punch cards, read/write, assembly language
▪ Integrated memory
 Turing Machine (c. 1931)
▪ “Turing-Complete”
 Modern Computers
▪ Store, retrieve, and process data
▪ Programmable

Von Neumann Architecture
 CPU: Processes data and programs
 Memory: Stores data and programs in circuits
 Input/Output: Data to/from user or auxiliary
storage

Fetch-Decode-Execute Cycle
 Control Unit gets the next instruction from
memory
 Determine what actions it requires
 Do those actions

Supercomputer
 Used for massive calculations (e.g.
Weather forecasting)

Mainframe computer
 Deal with large volumes of input/output
(e.g. Google)

Minicomputer (between mainframe
and personal)
 Multi-user, declined in use in mid-90’s due
to cheap microprocessors

Microcomputer (personal computers)
 Ubiquitous nowadays
 From desktops to mobile devices

Servers
 Dedicated to a single service
 E.g., Web servers, File servers

Personal Computers
 Standard desktop/laptop

Mobile Devices
 Smart phones, Tablets, Smart
cards

Embedded Computers
 E.g., In a car or washing machine

Types of parts
 Input devices
 Output devices
 Auxiliary Storage
 Main System

Keyboard
 Primary input device
 Input of alphanumeric characters

Mouse
 Pointing and clicking (Graphical interaction)
 Used in conjunction with display screen
 Selection, positioning (cursor), drawing, moving

Microphones
 Convert sound waves to data
 Sampling rate measured in Hz
(samples per second)

Scanners
 Convert light into data
 Like coloured photocopiers
 Picture quality measured in Pixels Per Inch (PPI)

Controllers/Joysticks
 Specialized inputs for game interactions

Many more...
 Cameras/Webcams
 Stylus/light pen
 Fingerprint/Bar code readers
 Motion capture
 Magnetic Resonance Imaging (MRI)
 Positron Emission Tomography (PET)

Display monitors
 Cathode Ray Tube (CRT)
 Liquid Crystal Display (LCD)
 Organic Light Emitting Diode (OLED)
 Augmented Reality
 Virtual Reality

Display monitors
 Pixels
▪ Short for “picture elements”
▪ Smallest electronic display elements
▪ Grid of pixels composes a digital image
 Resolution is the number of pixels (rows x cols)
 Dot pitch is the distance between pixels
 Size is diagonal length of the monitor
 Refresh rate is the display frames per second (Hz)

Speakers
 Convert data to sound
 Vary in sound quality
▪ Wattage, Frequency Response,
Signal-to-noise ratio, etc

Printers
 Dot-Matrix printers
 Ink/Bubble Jet printers
 Laser printers

‘Permanent’ storage of information
 Read/write data from/to storage
 Many forms over time
▪ Floppy Disk (8”, 5.25”, 3.5”)
▪ Hard Disk
▪ CDs, DVDs
▪ Flash memory

Central Processing Unit (CPU)
 Brain of the computer
 Different brands (Intel, AMD, others)
 Different speeds (166MHz – 4.7GHz)

Multi-core processors
 Multiple independent CPUs
 ‘Hyper-threading’

Main Memory
 Short term, working memory of the computer
 Random Access Memory (RAM)
 Volatile (erased when power goes out)
 Much faster than auxiliary storage
 Various sizes and speeds

Motherboard
 Holds everything
together
 Busses connecting the
components
 Vary in terms of
support for parts

Power Supply
 Must supply enough
wattage for all the parts

Case
 Various form factors
a)
b)
c)
d)
USB 2.0
PS/2
VGA
DVI
e)
f)
g)
h)
HDMI
LAN (Ethernet)
USB 3.0
Audio jacks

Hardware
 The physical components of the machine
 Processor, motherboard, memory, drives, etc..

Software
 A program (set of instructions)
 Downloaded, installed, executed

Firmware
 A program built into a microchip
 Bios (configuration), system settings, boot up

System software
 Operating system (DOS, Windows, OSx, Linux)
 Hardware drivers

Applications
 Utility applications (virus scans, etc)
 Personal (email, games, web browser)
 Business (word processors, spreadsheets,
databases, communication)
 The list goes on....

Copyright
 Piracy
▪ Illegal copying of software and media
 Sampling & Sharing
 Open source software
 Copyleft

Bugs
 1945 Harvard: A moth found inside a huge
computer
 Imperfect software, can cause crashes or worse!
 Patches are updates that fix known bugs
 Many bugs are unknown
▪ Testing (alpha/beta) & debugging
 E.g. Y2K bug
▪ (did not cause milk cartons to leak)

Viruses
 Malicious programs
▪ Can erase data, upload bad data, replicate
▪ Must be run on your system to infect
▪ Trojan viruses can open the door to others
 Anti-virus scans files for known patterns

Security
 Theft of data can be very costly/dangerous
 Keyloggers (a type of virus)
 Hackers
▪ Crack passwords
▪ Dumpster diving for info
▪ Social Engineering

Encryption is a major field of Computer
Science

Privacy
 Individuals expect communications to be private
 Tracking cookies, user profiles
 Security vs. Privacy
▪ NSA surveillance
▪ Canadian Bill C-51

Ergonomics
 Comfortable Human-Computer interaction
 Chronic repetitive stress injuries
 Proper design of keyboards, mice, chairs, desks,
etc.