9pin to HP48 Pin Serial Cable Pinout
From AllPinouts
Cable pinout for: 9pin to HP48 Pin Serial
This adapter will enable you to connect a HP48 Calculator at the ) 9 pin computer serial port.

9 PIN D-SUB FEMALE to the Computer.
+---------+
| O O O O |
\---------/
4 3 2 1
4 PIN HP48 to HP Serial Port
| 9-Pin | HP48 | |
|---|---|---|
| Carrier Detect | 1 | |
| Receive Data | 2 | 2 |
| Transmit Data | 3 | 3 |
| Data Terminal Ready | 4 | |
| System Ground | 5 | 4 |
| Data Set Ready | 6 | |
| Request to Send | 7 | |
| Clear to Send | 8 | |
| Ring Indicator | 9 |
