fix 07_timer.pl to work again after removing the ranoutoftime label.
also commented out the 'try to mess it up' code that modifies an immediate value in the code.
fix up 01_plotonscreen.pl to pass again; 0473db689a020d80dff1cedc455e1602215b494d changed lastline treatment so that 0xff indicates no last line instead of 0, and some of the symbol names changed.