This cable is suitable for PCs with a 25-pin serial port. Of course, you can easily get 25-pin<>9-pin convertors, so it can also be made to work with a PC with a 9-pin serial port.
Z88 (9-pin) PC (25-pin) TxD 2 -------------------- 3 RxD RxD 3 -------------------- 2 TxD RTS 4 -------------------- 5 CTS CTS 5 -------------------- 4 RTS GND 7 -------------------- 7 GND DCD 8 -------------------- 20 DTR +5v 9 -------------------- 6,8 DSR,DCD