bitwise logic/arithmetic problem

This isnt strictly a picaxe problem, but more of a logic one I think:-
I'm trying to find a relationship between the following 2 columns of data:

10000000 8
1000000 7
100000 6
10000 5
1000 4
100 3
10 2
1 1

The only one I can come up with is 'counting from the lsb of the 1st number, the position of the '1' is the number in the second column.'

I'm hoping there is some arithmetic/logical relationship, as It would be very handy to use in a calculation. I'm sure there is, but I can't think of it.

Is there one? How would I take the number decimal 8 and arrive at binary 10000000 (decimal 128)?

I think I just worked it out, please ignore this thread...

moorea21 said:

... please ignore ...

Click to expand...

Glad you worked it out, and sorry to ignore your request to ignore, but two points which may help others who find this thread.

It's clearer if the leading zeros are shown:
10000000 8
01000000 7
00100000 6
00010000 5
00001000 4
00000100 3
00000010 2
00000001 1

And if you're using an X2, check out the NCD and DCD commands.

moorea21 said:

I'm trying to find a relationship between the following 2 columns of data:

Click to expand...

The relationship is -

leftColumn = 2RightColumn-1

moorea21 said:

How would I take the number decimal 8 and arrive at binary 10000000 (decimal 128)?

Click to expand...

b1 = 8
b2 = 1 << b1 >> 1

b1 = 8
b2 = DCD b1 >> 1

b1 = 8
LookUp b1, ( 0, 1, 2, 4, 8, 16, 32, 64, 128 ), b2

Data 0, ( 0, 1, 2, 4, 8, 16, 32, 64, 128 )
b1 = 8
Read b1, b2

Table 0, ( 0, 1, 2, 4, 8, 16, 32, 64, 128 )
b1 = 8
ReadTable b1, b2