if I was to use: mov ax, 0x0904
would it be stored with ah being 0x04 and al being 0x09 or would it be the other way around?
if I was to use: mov ax, 0x0904
would it be stored with ah being 0x04 and al being 0x09 or would it be the other way around?
The other way around - AL will be 4, AH will be 9. H in AH stands for "high", L stands for "low".
x86 is a little endian machine though. If you store the same value in memory, say, at address 0x1000, the byte at 0x1000 will be 4 and the byte at 0x1001 will be 9.
On a side note, hex numbers 0x04 and 0x09 are 4 and 9, respectively.