How do you go from some silicon wafer with some metallic lines printed on it to having a GUI desktop. I don’t understand the intersection between hardware and software at the fundamental level.
In: Technology
Imagine a CPU+RAM as a giant excel spreadsheet. Each spot is just numbers, or equations that reference other numbers (all in 0/1 binary)…but it’s all just numbers and the CPU is built to do some basic operations on those numbers.
A program loads itself into the CPU and it starts with the first command in A1. Which can do an assortment of basic operations (see x86 assembly language)
A1 box might say “add B3 to C3 and store in J45”, then A2 says “if J45 is > J46, place ’55’ into M18, display M18 to the pixel”….showed a red(55) pixel on wherever M18 is drawn on screen….(all those numbers are made up, but so are the numbers in a CPU)…there is also a jump command to skip ahead/behind to repeat commands in code “if J45==16, jump to command B43”
We’ve given numbers in the CPU meaning, every single number is either a command, a Value, a location, a letter, a volor…etc. it’s all just numbers being moved around. Billions and billions of numbers. Some numbers become letters, some numbers are decimals, some are integers,,,,etc, it’s all about how we add meaning to the numbers via standards. (IEEE floating point, tells us how to interpret a chunk of 0/1 numbers into a decimal point number. ASCII tells us how to interpret a number into a character(letters). 24bit color tells us how to turn numbers into colors. X86 tells us how to interpret numbers into CPU commands. (All these standards are made up by humans to map 0/1 numbers into meaning)
It starts as very simple CPU level commands, and eventually fills a grid of pixels on screen that you see, while in the parts you don’t see, it’s storing numbers and values it needs.
It’s storing the letters I’m typing into a row of memory, and turning them into pixels you see. It has blocks of memory that describe the pattern for this font(letter to pixel diagram), and when told to print the ASCII letter ‘S’, it can look that pixel display up.
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