4 word x 4 bit register file (3 state) Octal D-type latch with 3 state output inverting 8 binary counter register with 3 state output 8 bit equality comparator Octal D-type flip flop with 3 state output inverting 8 bit shift register with output latches (3 state) 8 bit latch/shift register 8 bit register binary counter BCD to 7 segment latch/decoder/LCD driver