Ok, so I know that the alphabet of computers consists of only two symbols, or states: zero and one.
I also seem to understand how computers count beyond one even though they don’t have symbols for anything above one.
What I do NOT understand is how a computer knows* that a particular string of ones and zeros refers to a number, or a letter, or a pixel, or an RGB color, and all the other types of data that computers are able to render.
*EDIT: A lot of you guys hang up on the word “know”, emphasing that a computer does not know anything. Of course, I do not attribute any real awareness or understanding to a computer. I’m using the verb “know” only figuratively, folks ;).
I think that somewhere under the hood there must be a physical element–like a table, a maze, a system of levers, a punchcard, etc.–that breaks up the single, continuous stream of ones and zeros into rivulets and routes them into–for lack of a better word–different tunnels? One for letters, another for numbers, yet another for pixels, and so on?
I can’t make do with just the information that computers speak in ones and zeros because it’s like dumbing down the process human communication to the mere fact of relying on an alphabet.
In: 264
It doesnt know and doesnt have to. The CPU has a very basic, general purpose instruction set, for like addition, comparison, etc of units of 32/64/… bits. You can orchestrate those basic instructions to build higher level operations for your specific data type by using multiple of those basic instructions.
Want to compare two strings? Iterate over every 16 bit word from it’s starting address on, and check if each of them is equal, until one of them is a zero (marks the end of it).
This means that even stuff that could be a one-liner in your programming language, can create a large amount of those basic instructions.
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