String Question

Hello, I would like to be able to do the following but have not figured out a way to handle it $string="abcdefghijklmnopqrstuvwxz"; I would like to divde the above string into separate strings 8 charactes long , example $string1=abcdefgh $string2=ijklmnop $string3=qrstuvwx $string4=yz if the string were only 10 long $string=abcdefghij then $string1=abcdefgh $string2=ij any suggestions would be greatly appreciated. Thanks, Randy