The Cube Generator in Ultima VII involves a really complicated puzzle where the Avatar has to create bridges, evade traps and figure out how to bypass invisible walls. To make it easier, here a solution to this puzzle.
All numbers in the text reference to the picture below.
First create Bridge 1. Create 4, then 3. Walk over 5 and north to create 7 and 10. Walk over 7 then north to create 17. Next go south then over ten to create 9 and 18. Walk over 9 to create 8. Walk back north and then over 18, then a little west to create 19. Walk over 19 and then west to create 14 and 21. Walk over 14 then west (careful, fire fields) then onto 21 to create 13 and 15. Return to 19 and walk south over 15 to activate 20. Walk over 13 to 20, then south to activate 11 and 16. Walk over 16 onto 11 to activate 6. Walk south, over 6 and then north to create 2 and 4 (if not created yet). Walk over 6 and 4 back to the beginning. Walk north first over 2 then over 8. Go west to activate 23 and 12 (fire field directly on the trigger). Now walk over 12 to the prism and activate it.