Page Comparison

IN:    A = EP_DIR
     BHL = pointer to store returned filename (B=0 means local pointer).

OUT: Fc = 0:
          Filename returned at (HL), null-terminated.
     Fc = 1:
          A = RC_EOF ($09), no more filenames on File EPROM.
          A = RC_FAIL ($16), File EPROM not available.

Registers changed after return:
  ..BCDEHL/IXIY same 
  AF....../.... different