Hi. I've been browsing this forum for a while and I have a question.

Do the DB/DW/DD/etc keywords operate the same in .code/.text as they do
in .data? For some reason, the following code causes an access violation:

dd vga 0
setvga:
mov eax, [esp + 4]
mov dword [vga], eax
ret 4

Why doesn't this work? vga is defined in the .code section directly before this
procedure.

Thanks.

Also, here is a procedure I wrote that refers to bytes defined inside code, and it works perfectly, so I don't understand why the previous code doesn't.

; n2th(*t, n) - Convert 32BIT number to unsigned hexadecimal text

db '0123456789ABCDEF'
n2th:
mov eax, [esp + 8]
mov ecx, [esp + 4]
xor edx, edx
@@:
mov dl, al
and dl, 15
mov dl, [(n2th-16) + edx]
mov [ecx], dl
inc ecx
shr eax, 4
jnz @b
mov byte [ecx], 0
push ecx
call trev
ret 8

.code section maybe has not atrribute "writeable"?
see macro '.code' and macro '.data' and compare it.(and if you need correct ".code" macro(add writeable attribute))

it's best to use macros only when you understand them. for example, instead of .code you can write section '.text' code readable executable. To make it writable, change this to section '.text' code readable writeable executable

Oh, I forgot the "writeable" attribute It was: section '.code' code readable executable.

Thanks everyone.