>> >I need to us a 16F84-04 to drive a 3 or 4 digit 7 segment display
>> >(common
>> >annode or cathode, doesn't matter).
>> >
>> >I need to be able to send a serial number to the chip (9600,8,N,1) in
>> >the
>> >range of 0 to 9999 and have it display it. I think interrupts will be
>> >required because the display needs to be multiplexed and at the same
>> >time
>> >needs to check for serial data.

One possibility is to use the Philips SAA1064 chip, a 4-digit LED-driver
with I2C-Bus interface. It's not async serial, but it does give you two
wire (plus ground) comms and it handles all the multiplexing, decoding and
everything.

The Philips website has the datasheet.

Stephen.