Why aren't EXE's in binary?

Question

Why is it that if you open up an EXE in a hex editor, you will see all sorts of things. If computers only understand binary then shouldn't there only be 2 possible symbols seen in the file? Thanks

Answer 1

You're confusing content with representation. Every single file on your computer can be represented with binary (1s and 0s), and indeed that's how it's generally stored on disk (alignment of magnetic particles) or RAM (charge).

You're viewing your exe with a "hex editor", which represents the content using hexadecimal numbers. It does this because it's easier to understand and navigate hex than binary (compare "FA" to "11111010").

So the hexadecimal symbol "C0" represents the same value as the binary "11000000", "C1" == "11000001", "C2" == "11000010", and so on.

Answer 2

The hexadecimal values are interpreted binary values in memory. The software only make it a bit more readable to human beings.

0000 = 0
0001 = 1
0010 = 2
0011 = 3
0100 = 4
0101 = 5
0110 = 6
0111 = 7
1000 = 8
1001 = 9
1010 = 10 A
1011 = 11 B
1100 = 12 C
1101 = 13 D
1110 = 14 E
1111 = 15 F

Answer 3

Computers don't only understand binary, that's a misconception. At the very lowest, lowest, lowest level, yes, data in digital computers is a series of 1s and 0s. But computer CPUs group those bits together into bytes, words, dwords, qwords, etc. The basic unit dealt with by a modern CPU is a dword or a qword, not a bit. That's why they're called 32-bit or 64-bit processors. If you want to get them to work with a single bit, you pretty much end up including 31 or 63 extraneous bits with it. (It gets a bit blurry when you start dealing with flag registers.)

Digital computers really came into their own as of 8-bit processors, so hexadecimal became a very useful display format as it succinctly represents a byte (8 bits) in two characters. You're using a hex editor, so it's showing you hex, and because of this early byte-orientation, it's showing you two characters for every 8 bits. It's mostly a display thing, though; there's little reason it couldn't show you one character for every 4 bits or four characters for every 16 bits, although file systems generally work on byte granularity for actual data (and much, much larger chunks for storage allocation granularity -- almost always 4k or more).