> ASL vs ROL and LSR vs ROR. What's the difference?

ASL vs ROL and LSR vs ROR. What's the difference?

Posted at: 2014-12-18 
Shifting bits changes the value.

0110 is 6.

If you shift the bits to the left, you get 1100, which is 12.

If you shift them to the right, you get 0011, which is 3.

Shifting to the left by x places is the same as multiplying by 2^x, to the right is division by 2^x.

What's the difference between these instructions:

ASL vs ROL (both shifts bits left)

LSR vs ROR (both shifts bits right)

There has to be some difference, but I can't figure out what it is.