Hardware Outline 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

Hardware Outline What is a Computer?/Components of a Computer System Hardware That Computers Typically Have Hardware Components Central Processing Unit (CPU) Central Processing Unit Storage (Primary & Secondary) Main Memory Bits, Bytes, Words How Data Travel Between Memory & CPU Loading Data from Main Memory into the CPU Cache: Eliminating Speedbumps for the Bus Secondary Storage CDROM/DVDROM/Why Are Floppies So Expensive Per MB? Input & Output Devices Putting Bits Together Powers of 2 Kilo, Mega, Giga, Tera, Peta

What is a Computer? "... [A] programmable electronic device that can store, retrieve and process data."

compact disc

(N. Dale & D. Orshalick, Introduction to PASCAL and Structured Design, D.C. Heath & Co., Lexington, MA, 1983, p. 2)

ZIP

Hello ...

Components of a Computer System COMPUTER SYSTEM

HARDWARE

SOFTWARE

Physical devices

Sets of instructions

DON’T PANIC! This discussion may be confusing at the moment; it will make more sense after you’ve written a few programs. 1

2

Hardware That Computers Typically Have

Hardware Components HARDWARE

Central Processing Unit (CPU) Primary Storage

CENTRAL PROCESSING UNIT

Secondary Storage

Control Unit

Input Devices Output Devices

STORAGE

INPUT/OUTPUT

Primary Basic I/O

Multimedia

$1600/MB 80,214 MB/sec

Keyboard

Speakers

Cache

Arithmetic/ Logic Unit

Main Memory

Mouse

Amplifier

$0.83/MB 4,096 MB/sec

Monitor

CD/DVD

Registers

Secondary

Printer

Joystick

Hard Disk

etc

Note: storage costs and speeds are based on available PC systems, Jan 2003. Prices, specs courtesy of: bestbuy.com buy.com cendyne.com creativelabs.com pricewatch.com toshiba.com

etc

Networking

CD−RW $0.0005/MB 7.6 MB/sec

Modem

Zip Disk

Internet Port

$0.036/MB 2.4 MB/sec

etc

Floppy Disk $0.10/MB 0.03 MB/sec

etc

3

Scanner

$0.0017/MB 100 MB/sec

4

Central Processing Unit (CPU) The Central Processing Unit (CPU), also called the processor, is the “brain” of the computer. It has three main parts: the Control Unit, the Arithmetic/Logic Unit and Registers. The Control Unit decides what to do next; for example: – load data from main memory into the registers (see below); – perform an arithmetic or logical operation (see below); – store data from the registers into main memory; – choose among several possible courses of action (branch). The Arithmetic/Logic Unit (ALU) performs arithmetic & logical operations. – Arithmetic operations: add, subtract, multiply, divide, etc. – Logical operations: compare two numbers to see which is greater, check whether a true-false statement is true, etc. Registers are memory-like locations where data reside when they’re being used right now; for example, the operands being used by the current arithmetic or logical operation, or the result of the arithmetic or logical operation that was just performed.

Central Processing Unit Control Unit Load Next Instruction

Increment Instruction Pointer

Find Data Addresses in Memory

Load Data from Memory

Execute Instruction

Store Result in Memory

... Arithmetic/Logic Unit Add

Multiply

Divide

R03 = R03 + R63

R02 = R00 * R01

R02 = R00 / R01

Compare

Bit Shift

Bit Invert

R00 < R01?

R00