For reference purposes, here is the pinout for the Zilog Z80 CPU.

Yellow

• A0 to A15 = Address bus

Blue

• D0 to D7 = Data bus

Pink

• CLK = Clock signal

Red & Black

• VCC = +5v
• GND = Ground

Purple

• RFSH = outputs a signal to allow for memory to be refreshed
• M1 = Z80 is fetching next instruction from memory
• RESET = used to reset the Z80
• BUSRQ = Bus Request (used by external devices to request control
• WAIT = makes the the Z80 wait during a read or write operation
• BUSACK = Bus Acknowledge – signals when Z80 is ready to hand over control
• WR = signals a memory or I/O write operation
• RD = signals a memory or I/O read operation
• INT = hardware interrupt occurred
• NMI = Non Maskable Interrupt (higher priority than the INT)
• HALT = Z80 is in a halted state
• MREQ = Z80 wants to access memory
• IORQ = Z80 wants to access an I/O port