well, I guess that you can only have bit arrays up to 256 elements, but I was thinking something like this..

Code:
bigarray 	var	  bit[256] 'Large array to hold data
newdata	var	  bit   'newest bit to be shifted in
index		var	  byte


for 0 to 255
    bigarray[index] = bigarray[index +1] 
    next index
    
bigarray[255] = newdata  'put the newest data bit into the array
Maybe with 4 big arrays you could shift through 1024 steps?
Or have I missed the point entirely...