Binary Review

LET’S REVIEW THE BINARY SYSTEM

Binary symbols (O / I) represent electrical impulses.

Sends Electricity Receives

BITS & BYTES

The symbols O and I are considered a “bit”.

8 bits = 1 byte

LOOK AT THE KEYBOARD

• Notice the different keys.

• How many keys are there?

• What about function keys?

• Upper case/ lower case.

HOW MANY BITS?

Using only O & I how many are needed to represent ever key?

Let’s try a combination of 2:

OO

OI

II

IO

OK, four keys can be represented.

Let’s try a combination of 3:

OOO

OOI

OIO

IOO

III

IIO

IOI

OIIOK, not enough with three.

How many bits are needed?

How many bits are needed?

We need a total of eight (8) symbols or bits to represent every key on the keyboard.

8 Bits = 1 Byte

ASCii Code

The ASCii code assigns a numerical code to each letter. Here is an example:

A = 65 B = 66C = 67

Binary Code

How do the numbers from the ASCii code translate to Binary?

Let’s go back to kindergarten……

Let’s analyze the number …

5281What does this number mean?

The 1 has a place value.The 8 has a place value.The 2 has a place value.The 5 has a place value.

1000 100 10 1

5 2 8 1

Calculate:

5 x 1000 = 5000

2 x 100 = 200

8 x 10 = 80

1 x 1 = 1

Binary

This technique is also used in binary system.

In the decimal system we use 10 symbols to represent each number.

The binary system is based on 2 (O / I).

Any number can be represented by a series of O/I.

Convert Binary to Alpha/Numeric –

STEP 1: Set up place values.

STEP 2: Add up all place values containing I.

STEP 3: Look up translator (ASCii) number on table to identify key value pressed.

Binary Math Steps

Convert to Binary to Alpha/Numeric

0 0 1 0 1 0 0 1

2 symbol eight place value.Add all the 1s: 32

8 141

128 64 32 16 8 4 2 1 STEP 1

STEP 2

Convert to Binary to Alpha/Numeric

STEP 3

Translator (ASCii) # 41 = )

Decimal to Binary

Let’s translate the #50 to binary code:

128 64 32 16 8 4 2 1

0 0 1 1 0 0 1 0

50- 32- 16- 2

___

0

Convert Alpha/Numeric to Binary

Now let’s try to other way….

STEP 1: Get translator number by looking up key value on ASCii chart.

STEP 2: Set up place values.

STEP 3: Starting on left with place value 128, place an I in every

Value that will divide into the ASCii number.

STEP 4: Check it! Add up all place values containing I. The number

should equal your ASCii number.

Decimal to Binary Practice

Convert the following key to binary:

Z = AACii (Translator) #

90

Trick: Even #’s end in O and odd #’s end in I.

STEP 1

128 64 32 16 8 4 2 1

STEP 2

Decimal to Binary Practice

STEP 3

0 1 0 1 1 0 1 0

STEP 4 6416 8 2= 90

Z = 90 =