Equivalents for AppleCat Novation chips? (esp. on PLI)

[gledford@fcircus.sat.tx.us (Gordon Ledford)]

    A friend's AppleCat II died and I have narrowed the problem down to
    the chip on the PLI module labeled Novation 138430 (in a 20 pin DIP).
    Does anyone know if this chip is actually custom or if it is a
    relabeled part with a standard equivalent?  I'm not even sure what
    this chip is doing - it could be anything from a transistor array to
    a filter of some kind - does anyone know?  Has anyone worked out the
    schematic for the PLI?  (I have the schematic for the main board.)
    If you can shed any light on these matters I'd appreciate it.
    
    Thanks.
    
    Gordon Ledford                              gledford@fcircus.sat.tx.us