This version of OISP is one of the few processors that is not turing complete when memory is added. To make it turing complete, the program counter (PC) needs to be able to be accessed by the CPU via its PC read (PCRD) and PC write (PCWR) pins. Since the ALU is not a part of the processor, it has to be memory mapped as well.

CLK			Clock
Din			Input data bus. 8-bits.
Dout		Output data bus. 8-bits.
ADDR		Address but. 8-bits. Large look-up tables are not recommended.
WR			Write to memory.
RD			Read from memory.
PCWR		Write to PC.
PCRD		Read from PC.