How does binary translate to hardware?

Question

I understand how the code is compiled to assembly, and that assembly is a 1:1 replacement with binary codes. Can somebody help me understand how binary is conne

Answer 1

A complete answer to your question would encompass a book, and a fairly thick one at that.

When you say "code" I'm assuming you're referring to a high level compiled language, like C++. Usually, a compiler translates this code into machine language, or binary as you state in your question. We'll neatly avoid all discussion of managed vs. unmanaged code, p-code, etc. That is, we're just talking about compilers that target specific processors/operating systems. Java, for example, compiles into a pseudo-code called bytecode. We're also going to avoid the whole matter of link editing, or linking, which is how multiple source modules get compiled into machine language then bound together into a single executable program.

Okay, now that we've covered most of what we're not going to cover, here's what usually happens. And by "usually", I mean most compiled languages in a DOS, Linux or Windows environment. The source code is translated into machine language, which is written out to an executable file. This executable file contains, more or less, an image of what the program should look like in memory. When you tell the operating system to run your program, the OS's equivalent of a "Load and Go" executes. What that means is that the memory image in the executable file is loaded into memory, then the operating system does a machine language JUMP to the first instruction in the program. The CPU then blindly follows the instructions from thereon, until an EXIT is encountered.

This whole JUMP... EXIT nastiness is a drastic oversimplification for modern OS's. As you can imagine, if the CPU were to follow, with blind obedience, the instructions in a program that's gone astray, the computer would crash... or worse. Such was the fate of many an errant program in the early days, and a prime contributor to many a BSOD.