it is not a big problems if u used 74374,74244 and a 4X16 decoder
use dataport for input and o/p
decoder to the control port
In this case u can get 120 i/o . 64 input +56 outputs as u wish
see this link
http://booksbybibin.14.forumer.com/viewtopic.php?t=53
Bibin John
www.bibinjohn.tk