>There's a 21164 chip listed on ebay that has the markings on it
>"21164-KC 533"; is this a 499-pin 21164/21164A or a 413-pin 21164PC?

I'm not 100% certain Jeffrey, but there's some circumstantial 
evidence it's not a 21164PC on:

     http://www.dais.is.tohoku.ac.jp/~kabe/vsys/cpuheat.txt

(the only page google found for me containing the string "21164-KC"), 
viz. both are listed on different lines of the table:

21164-KC 533MHz 19.9A    43.5W  67.6℃
21164-MC 600MHz 22.3A    48.5W  65.6℃

21164PC 533MHz   8.3A    18.0W  66℃      2.0V+2.5V
21164PC 600MHz   9.3A    20.0W  65℃
21164PC 666MHz  10.3A    23.0W  63.5℃


I was looking for a 21164PC chip a few months ago.  The only source I 
found was ReQuest in Holland.  I didn't proceed with the purchase in 
the end but I'll append the reply I received at the time to this 
email.


Ray



Reply-To: "Michel Brouwer - ReQuest Automation Services" <brouwer@request.nl>
From: "Michel Brouwer - ReQuest Automation Services" <brouwer@request.nl>
To: "Ray Phillips" <r.phillips@mailbox.uq.edu.au>
Subject: Re: 21164PC
Date: Tue, 6 Nov 2001 10:12:57 +0100
Organization: ReQuest Automation Services

Dear Sir,

We have the 533MHz CPU's available for 100 USD.

With kind regards,

Michel Brouwer

Email:brouwer@request.nl
Homepage:www.request.nl
Phone: 0031-35-6949441
Fax: 0031-35-6946202

----- Original Message -----
From: "Ray Phillips" <r.phillips@mailbox.uq.edu.au>
To: <sales@request.nl>
Sent: Tuesday, October 23, 2001 12:41 AM
Subject: 21164PC


>  Dear Request:
>
>  Please tell me if you can supply a DEC 21164PC microprocessor which is
used
>  by the Alpha PC164SX motherboard.  I believe they were made in three
speeds
>  400 MHz, 466 MHz and 533 MHz, with part numbers 211PC-01, 211PC-02 and
>  211PC-03, respectively.
>
>
>  Ray Phillips