I need help in Assambler ,
which makes the command DUP in this line
APRI DW 2 DUP(5, -6)
I need help in Assambler ,
which makes the command DUP in this line
APRI DW 2 DUP(5, -6)
APRI is the tag
DW is type word (16 bits)
2 is the number of times to duplicate
DUP duplicates and initializes with the values you give
in this case APRI points to 2 groups of 2 words one with the value 5 and another with the value -6, or in other words "using words 2 times (5, -6)"
(signed short 16bit) 5 : 0005
(signed short 16bit) -6 : FFFA
In x86 intel memory the numbers are saved with the least significant byte first for being little endian (although the newest of intel handle both endiannes) so in memory would be:
05 00 FA FF 05 00 FA FF
that's why the DW (Define Word) is important because if you then treat it as a string of bytes every 2 would be "upside down".
Note: What I'm not sure is if every compiler would let you put a negative number in a word or if you have to specify it as signed word SWORD .