Mac to HP48 Cable

8 PIN MINI-DIN MALE (At the Computer)
NOT DRAWN YET (To the HP48).

8 PIN MINI-DIN MALE to the Computer.
4 PIN ??? FEMALE to the HP48

Mac HP48
TxD- 3   RxD
RxD- 5   TxD
GND+RxD+ 4+8   GND
Shield SHIELD SHIELD Shield