A friend of mine who often repairs old lab stuff has run into some board on which he has some Philips part, PCF4500WP in plcc44. The crystal is at pins 7 and 8. That is all the info he gave me when he asked me - and I know nothing about it. Perhaps someone here would have some info - datasheet or whatever, I'll just forward it to him.
I expect you already did a Google search and found the same thing I did, nothing. I see the number shows up on a site where you can try to get quotes, so they acknowledge that it existed and the time frame is right.
It is not very often that a part goes so totally missing like this unless it was some sort of a custom part perhaps. But then maybe it disappeared from view before the Internet, so no trace left behind.
The MC14500B seems the best guess so far (I did not know the 14500). He'll probably see the discussion tomorrow (I sent him a link to it on google groups). While I can imagine someone could put that in a plcc in the late 80-s or early 90-s I could not find any reference to such a thing (spent perhaps 15 minutes searching).
We had a large set of Philips databooks in the 90's, with regular updates. Unfortunately, almost all have gone now. But I did find IC25 from 1996. It's for the "16-bit 80C51XA Microcontrollers". In the intro section, there are the telephone numbers for the Bulletin Boards and Fax-on-Demand service, no web address. ;-) And it starts with an overview of all (? can't be sure it's complete) Philips microcontrollers at that time:
80C51 Family CMOS: 80Cxx, 83Cxx, 87Cxx
80CLXXX Family CMOS: 80CLxx, 83CLxx, 85CLxx
8051 Family NMOS: 8051, 8031, 8052, 8032
8400 Family CMOS: 84Cxx
8400 Family NMOS: 84xx
3300 Family CMOS: 33xx
16-bit controllers (68000 architecture): 68070, 93C101, 90CE201
16-bit controllers (XA architecture): XA-G1, XA-G2, XA-G3
Nothing with PCF numbers in there. What I rememeber from that time is that most PFCxxxx chips where (I2C) peripheral chips.
Stef (remove caps, dashes and .invalid from e-mail address to reply by mail)
Trouble always comes at the wrong time.
Thanks for all the replies and suggestions. I don't know how far he got, may be he has fixed the device already. He sent me also this a day or two ago (and I forgot to post it):
"The instrument is a Hartmann&Braun O2/CO2 meter URAS10E. A VFC output is connented to pin 6. Pin 13 seems to be serial I/O. Pin 14 seems to be clock for the serial transfer. Other pins looks to be parallel ports."