On 28 Nov 2006 at 15:27, Chris M wrote:
  Can this chip, said to be compatible with the Z80, be
 replaced by one altogether? 
IIRC, many manufacturers used them interchangeably with the "genuine"
Z80.  The datasheet says "software- and pin-compatible":
http://www.datasheets.org.uk/datasheet.php?article=3445183
Cheers,
Chuck