Understanding Sizes Memory and Logic
The start of the computer was a simple calculator. But how does it communicate?
Historically we count with out fingers. We have 10 fingers (including our thumbs) this is the basis for our number system. We count by tens. For example: For the number 9,605,872.145673…..
But how can represent numbers with electricity?
This is done by using the voltage of the input signal. A voltage of 0 to 0.2V gives us a “0” (zero) and a voltage of 4.4V - 5V gives us a “1” (one).
If we have one “digit” or a bit we can represent whether that something is there or it is not. This is somewhat similar to a light bulb…..
How many ways can you combine two objects with an “on” state (represent this with a 1) and an off state (represented with a 0).
Answer:
0 / 01 / 0
0 / 1
1 / 1
Now try combining three objects with both an ON state and an OFF state.
Answer:
0 / 0 / 00 / 0 / 1
0 / 1 / 0
0 / 1 / 1
1 / 0 / 0
1 / 0 / 1
1 / 1 / 0
1 / 1 / 1
Simply put, computers store data, send instructions to their CPU and stream data as a sequence of 1s and 0s.
This how numbers are stored and instructions are sent. It is the sequence and grouping of the numbers that determine what the numbers actually mean.
To represent numbers in binary (or machine) code:
With one bit……. 0 a zero
1 one
With two bits….. 00 zero
01 one
10 two
11 three
In fact:
To convert binary to decimal
To convert to binary from decimal:
OR
If we put 8 bits together we get a byte. This is the size of the original bus system in computers. 8 lines of data transmitted / transported information between the hardware components in the computer at a time synchronously.