2. Input/Output
Input is whatever is put into a computer.
Input can be data, letters, numbers, symbols, shapes,
sounds, pressure, light beams or whatever material
needs processing.
Output hardware consists of devices that translate
information processed by the computer into a form
humans can understand - print, sound, graphics, or
video, for example.
3. The Binary System
The base of all programs is the binary system, a
number system of two - 1 and 0.
These represent On and Off - the position for an
electrical signal to pass through (or not) a transistor.
All data and program instructions that go into the
computer to be processed and stored, are
represented by these binary numbers.
4. Decimal System
To understand the binary system, we need to review
our Base 10, decimal system.
The prefix “dec-” means 10
Our decimal system is based on 10 numbers
(0,1,2,3,4,5,6,7,8,9)
When counting, using place value, we fill the ones
place and then move to the tens place.
5. For example:
When you count in the
decimal system (base 10)
you fill the one’s place, then
move to the ten’s place.
Only the numbers 0 - 9 are
used.
As each place value is filled
with the numbers, we
continue to the next place
value. Each place value is
10x the previous place.
10’s 1’s
9
1 0
1 1
1 2
1 3
100’s 10’s 1’s
9 9
1 0 0
1 0 1
6. Counting in Binary (Base 2)
The prefix “bi-” means two.
The binary system uses only two numbers - 0 and 1.
We count in the binary system the same as in the
decimal system by filling in the place values and
moving up the place value chart.
If the decimal system, base 10 has place values 10x
the previous place - How do you think the place
values for the binary system are determined?
13. Bits and Bytes
Bit - In the binary system, each 0 or 1 is called a bit -
short for binary digit.
Byte - A group of eight bits. The letter “G” is a
representation of 1 byte (eight bits).
There are 256 combinations of bits available 28=256
14. The alphabet in binary
Binary Alphabet
O11OOOO1 a
O11OOO1O b
O11OOO11 c
O11OO1OO d
O11OO1O1 e
O11OO11O f
O11OO111 g
O11O1OOO h
O11O1OO1 i
15. Can you read this?
O11O1OOO_O11O1OO1
Binary code is the base code of computer
language.
Once you understand the patterns and the
rules, you can learn other programming
languages.
Have fun coding!
17. Additional Teaching Links
Text to Binary and Back Again
http://www.roubaixinteractive.com/PlayGround/Binary_Conversion/Binary_To_Text.a
sp
The Alphabet in Binary
http://www.tekmom.com/buzzwords/binaryalphabet.html
Cisco Binary Game
http://forums.cisco.com/CertCom/game/binary_game_page.htm
http://www.networkclue.com/hardware/computer/binary.aspx
http://en.wikipedia.org/wiki/Binary_numeral_system