<p>Hello Mr. George T,

A good site for expanding port pins on a 8051 
type IC can be view at the below web site. 
http://www.airborn.com.au/8051/2wio8051.html

When using single chip micro's, especially the 
smaller single chip micro's like the AT89C2051, 
it is often desirable to expand the I/O serially. 
One good method of serial expansion, practised 
widely, is the use of the i2c bus. The i2c bus 
is versatile, and needs only two wires for 
communication, but unfortunately the parts are 
a little expensive. If you need the versatility 
of being able to add not only parallel I/O, but 
devices like EEPROM, RAM and clocks, then the 
i2c bus is for you, and you should refer to the 
excellent application note from Atmel, or the 
full information from Philips, concerning this 
approach

Hope this helps.
Good luck,
Charles Bannister</p>