Why are 8 and 256 such important numbers in computer sciences?

Question

I don\'t know very well about RAM and HDD architecture, or how electronics deals with chunks of memory, but this always triggered my curiosity: Why did we choose to stop at 8 bi

Answer 1

The important number here is binary 0 or 1. All your other questions are related to this.

Claude Shannon and George Boole did the fundamental work on what we now call information theory and Boolean arithmetic. In short, this is the basis of how a digital switch, with only the ability to represent 0 OFF and 1 ON can represent more complex information, such as numbers, logic and a jpg photo. Binary is the basis of computers as we know them currently, but other number base computers or analog computers are completely possible.

In human decimal arithmetic, the powers of ten have significance. 10, 100, 1000, 10,000 each seem important and useful. Once you have a computer based on binary, there are powers of 2, likewise, that become important. 2^8 = 256 is enough for an alphabet, punctuation and control characters. (More importantly, 2^7 is enough for an alphabet, punctuation and control characters and 2^8 is enough room for those ASCII characters and a check bit.)