Bits & Bytes Help (beginner)

[tntcoder]

Hey guys,

Can someone explain this to me:

10000h in bytes is 4+4+4+4+4 = 20bytes yes? and because thers no 20bit reigster it goes in a 32bit dword. I think i understand that.

But then with this code as an example:

arrayD DWORD 10000h, 20000h
mov eax, arrayD ; eax = 10000h
mov eax, [arrayD+4] ; eax = 20000h

Right now i get that its +4 because 20000h is 4 bytes beyond the 1st element. What i dont understand is how is it 4 bytes beyond, why not 20 bytes as i said earlier?

Really having a problem getting my head around this?

Thanks for any help

 

[cpjust]

Each hex number is equal to 4 bits (half a byte), not 4 bytes.
For example, 0x01 is 8 bits, 0x0123 is 16 bits, and 0x01234567 is 32 bits (4 bytes).