On Dec 31,  8:07, Joe wrote:
     There's nothing remotely similar to this number
in either of my
 Signetics data books. Are you sure that it's a Signetics part? The
"MC"
  sounds more like a Motorola part. Is there a date code
on the part? 
How old are the books?  It's moderately recent (late 1990s), and I'm
fairly sure it's actually second-sourced by Philips from a Motorola
original (now obsolete, of course ;-))
--
Pete                                            Peter Turnbull
                                                Network Manager
                                                University of York