The simplest method to do a single LED chaser is

temp = 1
for a = 0 to 7
portb = temp
temp = temp >> 1
next

takes only 14 words

or if you want to be really tight in your code

temp.0 = 1
repeat
portb = temp
temp = temp >> 1
until temp.7 = 1

takes 8 words

Tim