1. DA 106 Introduction to Microcomputers Components
Mr. Turton
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

2. DA106 Intro to MicroComputer Applications and Programming
What is a computer?
Computer
one that computes (Webster’s dictionary)
In other languages:
French: ordinateur (from “order”)
Italian: cervello elettronico (“electronic brain”)
Other?
Computer: a programmable device that can store, retrieve and process data.
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

3. DA106 Intro to MicroComputer Applications and Programming
What’s in a Computer?
Hardware:
The actual physical machine
Consists of several hardware devices
Software:
The programs that tell the machine what to do, i.e. give instructions to the machine
Different types of programs written in different languages
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

4. DA106 Intro to MicroComputer Applications and Programming
Hardware Devices
Input:
Keyboard
Mouse, Touchpad, Joystick
Pen & tablet, Perforated cards
Output:
Printer
Screen (monitor)
Teletype
Input & Output:
Auxiliary Devices:
disks (hard disk, floppies, DVDs/CDs, USB keys, Flash memories)
tape drives
Touch screen
Network cards (intranet, internet)
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

5. DA106 Intro to MicroComputer Applications and Programming
Hardware Devices (2)
Memory
Permanent: Disks & other I/O devices
Volatile: Main memory, Graphic memories
Virtual
Main memory is like a very large set of mailboxes, each with its own address.
It stores data encoded as binary numbers.
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

6. DA106 Intro to MicroComputer Applications and Programming
Hardware Devices (3)
Central Processing Unit(s)
One or more
A CPU contains
Arithmetic Logic Unit (ALU)
A Control Unit: controls the actions of other components
Special Floating Point processors
The CPU controls just about everything else by executing instructions
stores data in memory
retrieves data from memory
performs computations
sends and gets data from other devices
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

7. DA106 Intro to MicroComputer Applications and Programming
Hardware Devices (3)
Bus: A group of wires through which the other devices communicate.
I/O devices are controlled by drivers, which are very specialized kinds of programs
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

8. Computers through Time
Vacuum tubes
Mainframe computers (IBM)
Mini computers (DEC)
Micro computers (IBM, NEC, MacIntosh)
Desktops
Laptops
Blackberry
Supercomputers
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

9. DA106 Intro to MicroComputer Applications and Programming
Hardware Trends
Every year or two computer power approximately doubles
Memory size (RAM)
Memory used to execute programs
Secondary storage (permanent storage)
E.g. disk storage, used to to hold programs and data over time
Processor speeds
Speed at which computers execute their programs
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton

10. Hardware/Software Trends
Applications:
Rapidly increasing hardware power allows applications to get bigger and more complex
Costs
Hardware costs dropping
Software development costs rising
Software development complexity
Programmer salaries
Cost of slipping schedules
Unanticipated interactions in complex systems
Unpredictability of software development times
28-January-2008
DA106 Intro to MicroComputer Applications and Programming
Mr. Turton