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Arrays
Arrays dapat diibaratkan sebuah rantai dari sebuah variable. A text string is an example of a byte array, each character is presented as an ASCII code value (0..255).

Here are some array definition examples:

a DB 48h, 65h, 6Ch, 6Ch, 6Fh, 00h
b DB 'Hello', 0


b is an exact copy of the a array, when compiler sees a string inside quotes it automatically converts it to set of bytes. This chart shows a part of the memory where these arrays are declared:


You can access the value of any element in array using square brackets, for example:
MOV AL, a[3]

You can also use any of the memory index registers BX, SI, DI, BP, for example:
MOV SI, 3
MOV AL, a[SI]


If you need to declare a large array you can use DUP operator.
The syntax for DUP:

number DUP ( value(s) )
number - number of duplicate to make (any constant value).
value - expression that DUP will duplicate.

for example:
c DB 5 DUP(9)
is an alternative way of declaring:
c DB 9, 9, 9, 9, 9

one more example:
d DB 5 DUP(1, 2)
is an alternative way of declaring:
d DB 1, 2, 1, 2, 1, 2, 1, 2, 1, 2

Of course, you can use DW instead of DB if it's required to keep values larger then 255, or smaller then -128. DW cannot be used to declare strings!

The expansion of DUP operand should not be over 1020 characters! (the expansion of last example is 13 chars), if you need to declare huge array divide declaration it in two lines (you will get a single huge array in the memory).

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