[ tulsamike3434 (at) gmail.com wrote...] Stop pulling your hair out and start doing some debugging... 8-) The error message is pretty self explanatory - either r+1 or s is outside the range for the DIM's in 110. 1. Start sticking in PRINT statements 115 print "***DBG: array dim", h, v 675 print "***DBG: before if", r+1, s to figure out what bad values (if any) you are getting. Then if bad values, start going back through the code - how do you get to line 670 (from 530 and 540 and, and....) try it to understand the program using the paper and pencil method to debug it (and a simple dimension of 1x2 2x3 etc, so you don't have to go through too many times) What is starting at 530? Looks like subroutines, since the code at 510, 520 is pretty much telling you that you need to go to 790+ Is your version of basic different than the Microsoft 8080 Basic for the Altair that the book was written for? How? cheers -- alex