Using the P89c66x series in most cases give you enough internal Flash and RAM that you can use all 32 pins for I/O. If you need more
a) use a CPLD
b) use a 8 port part (e.g. Cygnal)
c) Use IIC< Philips have parts that give you up to 32 (or is it 64) '51 type pins for the price of 2
d) use a PSD chip
e) use latches and input selector in discrete logic

erik