If you are interested in building your own 80C535-based microcontroller system, all can be found here on my homepage
(Get the PCB's)

The AVR Ethernet I/O board can be found at:

http://www.drftech.com

The WebCat can be found at:

http://www.achatz.nl

The Easy TCP/IP board can be found at:

http://www.mcselec.com

The Easy Ethernet  board can be found at:

http://www.edtp.com