Hex numbers representation in Assembly, hexadecimal numbers should be prefixed with a 0 if they start with a digit not in the decimal range 0-9 .

Hi,

I'm having an error on this sentence:

.data

myconst dd C0C0C000h ;<= error
myconst dd 0C0C0C00h ;<= works fine

Had to replace the first one by this:

myconst db 192, 192, 192, 0 ;<= works fine

It seems perfectly valid hex numbers starting with a letter produces an error.

Maybe I'm missing something obvious here, if so please delete.

Rgds, GdS

It's the way the MASM pre-compiler handles numbers.

It treats as numbers only the sequences beginning with a decimal digit, even if it's zero.

So, if you have a hexadecimal number, starting with a digit that is not in the decimal range (0-9), you must prefix it with 0, so that the pre-compiler will treat it as a number.
Prefixing the number with zero does not have any impact on the compiled code:

C0C0C0C0h == 0C0C0C0C0h

the same way as

010 = 10

E.G.

Thanks for your answer Samael, I do appreciate it.

Rgds, GdS