Reading hex

[Shannen Durphey]

Ok, you might have a series of increasing numbers like this.  I'm
going to copy a couple of lines from AKAR1180.bin.  I'm using a fixed
width font, 10 pt, wrapping lines at 70 chars.  If you use a variable
width font, there's no guarantee that things will line up.


         0  1  2  3  4  5  6  7     8  9  A  B  C  D  E  F
0000


0190    06 07 08 09 0D 10 11 11    11 11 14 18 1C 20 20 C0 
01A0    00 00 00 03 07 09 09 0C    0B 09 0A 0A 09 04 FF EC 
01B0    35 14 12 01 00 00 05 08    30 38 FF 10 E6 33 FE 80 

The value at 0x1B3 is 0x01.  0x1B3 be written as $01B3.  Most editors
show something like this table.  Some don't have the numbers across
the top, most have a feature that displays your actual position.  You
might want to try using hex workshop, or winhex, or another editor
that someone here is using just until you get up to speed.  

How is 1B3= 435?  2 answers, one easy, one not as easy.  1)  Because
the hex conversion feature of the windows calculator program says so.
: )  2)  You need to think about #'s for a minute.  Base 10 that we
usually use counts ten digits, 0,1,2...8,9 then marks a "restart" by
increasing the value in the column to the left, and starts again. 
...6,7,8,9, 10,11,12.  The #10 is 1 * 10 + 0 * 1. 

 Hex is hexidecimal, base 16.  It counts 16 digits, marks the
"restart", then starts again. 
0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,10,11,12.  What looks like ten, 10, is
1 * 16 + 0 * 1 decimal. We have no single digit numbers to represent
anything after 9, so we use A,B,C,D,E,F.  Hex 11 is 17 decimal (1 * 16
plus 1 * 1) decimal.  0x12 is 18 (1 * 16 + 2 * 1) decimal.  If you
move up to something like 0x3a, you get 3 * 16 + 10 * 1 decimal= 58
dec.   Hex value A = 10 in decimal.


0xFF is 255dec (15*16 + 15*1), then the count restarts again.  0x100
is 256, it's 1*16*16 + 0*16 + 0*1.  0x01B3 is 0*16*16*16 + 1*16*16 +
11*16 + 3*1, or 256 + 176 +3.  Lotsa "primers" or "tutorials" on
hexadecimal are available on the net.  

You might be able to select scientific view on your windows calculator
to do hex conversions.  Look in start, programs, accessories for
calculator.  Then select view, scientific after it's running.  Contact
me offlist if you don't think yours will show scientific view.  You
don't have to have a deep fundamental understanding of hexadecimal to
do tuning.  It helps, though.  The more you use it, the more you'll
get a "feel" for the conversions.  

Shannen

Kevin R wrote:
> 
> I'm using the edit capabilities of the software that came with the used
> Xeltec burner I have.
> It looks like a table with X and Y addresses or am I reading it wrong.
> 0 1 2 3 4
> A
> B
> C
> Also, all the entry points seem to be a 2 number entry.
> I guess what's giving me the problems is I don't know how to the 1B3=435
> part.
> 
> Kevin R
>
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