Note that the first position is numbered zero and not one.Įvery computer in the world has a limited number of bits. The following table shows the positional value of the first 16 bits in the binary number system, as a power of 2. Since it only has 2 digits the value of each binary digit in a large binary number is muliplied by a power of 2 instead of a power of 10 as we do for decimal numbers. The numbering system that uses only 0 and 1 is called the binary numbering system or simply binary. We count numbers inside computers exactly the same way except that the numbering system in computers does not have 10 digits, it only has 2 digits: 0 and 1 (bits!).

Each digit in a large decimal number represents that digit multiplied by a power of 10 based on its position and summed together. Thus we call the 1 the hundreds digit, the 2 the tens digit, and 3 the one's digit. The 1 in 123 does not represent 1 it represents 100. When you write a decimal number larger than 9 you must use two or more digits like this: 123 which is one hundred and twenty three. All decimal numbers are made using the ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. I must assume that if you can read the lessons in this class and understand them, then you must be familiar with decimal numbers and basic arithemetic like adding and subtracting. It is simply the most common method, and therefore has considerable support for it built into most microprocessors including the 650X processor Family used in most classic gaming consoles and computers from the late 70's and 80's. First, I want to reiterate that this is NOT the only way to count using bits. In this lesson, I will introduce that standard method. In previous lessons, I have hinted that there is a standard method for counting using bits.

Decimal to binary assembly program