OpenEuphoria

Re: Hexadecimal and whatever...

• Posted by James Powell <Wizard at DJO.COM> Apr 15, 1997
• 883 views

>Okay. I get this BRILLIANT idea and decide to star reading bytes from files.
>I need to make it a number, so I use bytes_to_int to change a set of four
bytes.
>Truth is, I'm seeing if I can read data in from a MIDI file (don't ask me
>why), and I read in the integer 101053452 (well, not exactly), but I'm
>supposed to get the hexadecimal 00000006. Anyways, I think the problem is
>that I need to read the bytes directly into hexadecimal. Anyone know how to
>do that?
>
>P.S. Anyone know what I'm talking about?
>
Heh, heh.  (<snicker, snicker>)
Ok, here's a possible solution.  Try it WITHOUT using bytes_to_int.
If you look at each of the 4 bytes that you combine into an integer (before you
combine them!) one of them should be equal to &H06 (hex value 6).

The problem is that 1 byte (8 bits) will hold 2^8 (256) values, ie &H00-&HFF.
If you combine 4 bytes (32 bits, and your basic integer type) you can now store
2^32 (4,294,967,292) values, or &H00-&HFFFFFFFF.
You want the hex value &H06 (00000006).  Since that is less than &HFF, it is
stored in a SINGLE byte, rather than a 4 byte integer.  When you combine the
four
bytes that you are reading, it makes a much larger value (10105342) than you
wanted.

Lets say that byte 1 = 00000006, byte 2 = 00000007, byte 3 = 00000001,
and byte 4 = 00000009. If we combine those we get &H06070109 ( i think) which
is a rather LARGE decimal number.

Anyway, just use each byte seperately rather than making an integer out of 4
of them.  Hope this helps.
James Powell