General Computer Stuff

Hardware: physical parts of a computer: CPU, drives, etc.

Software: Programs and Data

A computer needs both to be useful.

General Computer Stuff

Central Processing Unit (CPU)

Main memory

Output devicesMonitor, disks

Input devicesKeybard, Disks, mouse, etc

Note that some devices (disks, network card, touchscreen) can be used for both input and output.

General Computer Stuff

CPU Fetch-Decode-Execute Cycle:

CPU Fetches the code from main memoryCPU Determines what the instruction isCPU Executes InstructionRepeat

General Computer Stuff

Operating System:Controls input/output and resource management.Examples: Windows, MAC, Unix, Linux, Android

Application program:General term for software that is geared toward a single or a set of closely related tasks.Examples: Office Applications

General Computer Stuff

Digital: Discrete, numeric representation.Example: New HDTV signalsCD’s, DVD’s

Analog: Continuous, wave/pulse representation.Example: Old TV signals (and some cable)Vinyl records, VCR tape

General Computer Stuff

Other number systems:

We use base 10 (decimal) : uses 10 digits0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19…

Base 2 (binary): uses 2 digits0 1 10 11 100 101 110 111 1000 The numbers above correspond to 0-8 decimal

Base 16 (Hexidecimal): uses 16 digits0 1 2 3 4 5 6 7 8 9 A B C D E F GThe numbers above correspond to 0-15 decimal. 11H 16 DEC

General Computer Stuff

Digital Storage: All computers store information digitally.

This is achieved using the binary number system:

Bin 2^n dec

0000 0

0001 20 1

0010 21 2

0011 20+21 3

0100 22 4

0101 20+22 5

0110 21+22 6

0111 20+21+22 7

1000 23 8

N binary digits can represent 2n

bits (individual 0 or 1).

Computers

There are 8 bits in a byte.

0 1 0 0 1 0 1 0

1 1 0 0 0 0 1 0

0 1 0 0 1 1 1 1

0 1 1 0 1 0 1 0

0 1 0 0 1 0 1 0

Memory cells are usually 1 byte

Large values are stored in multiple(preferably) adjacent cells

General Computer Stuff

KB 210 = 1024

MB 220 (over 1 million)

GB 230 (over 1 billion)

TB 240 (over 1 trillion)

Unit Symbol Number of Bytes

kilobyte

megabyte

gigabyte

terabyte

Storage Capacities:

General Computer Stuff

1) Convert decimal to binary:a) 3 = 2 + 1 = 11 b) 12 = 8 + 4 = 1001

c) 64 = _____ d) 65 = _____

2) Convert binary to decimal: 5) Convert 50 GB to MB a) 100 = 4 6) Convert 50 GB to KBb) 101 = 4 + 1 = 5 7) Convert 1 GB to KBc) 10010011 = _____d) 00000010 = _____