Hi,
I''m posting this because this is a MAJOR language feature especially when dealing with game programming that I don''t understand one bit - and I haven''t found a good reference for - yet...
So I''m asking for someone''s help, or someone directing me to a good site, but here are some of my questions that have to deal with those bits and bytes...
What is a "Hi Word" and a "Lo Word" (Low Word)
Why is a Word a 16 bit value and a DWord a 32 bit value ?
What''s a high bit and a low bit ?
What''s the sign bit?
Do you read binary left to right - or right to left?
What do all the Bitwise Logical Operators do ? ( &, |, ~, etc...)
|
L-> In english please
Each hexcidecimal notation is 4 bits right ? e.g 0xF - 4 bits (1111)
Anyway - it feels great giving off that chest - and I would really like some help (as you can so planly see)
Any directions or help to any of these questions would greatly be appreciated - and yes - I don''t know how I got through programming games without it
Thanks,
Destroyer
word = 16 bits dword = double word (32 bits) loword = low word from a dword (16 bits) hiword = high word from a dword (16 bits) qword = quad word (64 bits)
The high bit is simply the most significant bit of any bit of a piece of data, so the high bit of a 16 bit word would be bit 16. The low bit is the least significant, ie bit 0.
Binary is normally written with the least significant bit on the left, so....
1000 = 8 0100 = 4 0010 = 2 0001 = 1
of course you normally dont bother writing the leading zeroes.
The bitwise operators perform logic ops on individual bits. eg
the shift operators shift the bit pattern up or down
0110 << 1 = 1100 0100 >> 2 = 0001
Finally, yes, a hex digit represents 4 bits (or a nybble - half a byte)
[edit] oops, missed one...the sign bit is the bit that tells you what sign a number is. If it is set high, the number is negative, if it is low, the number is positive. It is usually the top bit of a signed number. Note that you cant just flip the bit to make a number (eg 8) into a negative number (-8) - you have to use twos complement arithmetic to do the conversion. If you just flip the bit, 8 becomes -120. To convert x to -x, use this...
That''s helps a lot - I had to work through the Bitwise Logical Operators (&AND, |OR, and ^XOR) but I got it with a little help from a logic book called "The Logic Book" it contains stuff like that in there... I finally get it !
That helps a lot - I had to work through the Bitwise Logical Operators (&AND, |OR, and ^XOR) but I got it with a little help from a logic book called "The Logic Book". It contains stuff like that in there (Exclusive OR)... I finally get it !
Each hexcidecimal notation is 4 bits right ? e.g 0xF - 4 bits (1111)
Anyway - it feels great giving off that chest - and I would really like some help (as you can so planly see)
Any directions or help to any of these questions would greatly be appreciated - and yes - I don''t know how I got through programming games without it 
