I am building an eeprom programmer for the 28C64A (dip package) with my old basic stamp ii "homework" board (lost my arduino in the move). I have the first four address and data pins, as well as W E and G connected from P0 to P10. I am working with what I already have, so buying shift registers and friends is not an option. My question is that I read over the eeproms datasheet and it said nothing about leaving unconnected pins floating, so is it okay to do that, or must they be grounded?
Read the part about input current. Close to zero, right? It's a CMOS chip, so you must tie all the inputs to appropriate logic levels (high or low, depending on what you want).