Here is the pinout for the RS232 port on the HX-20. I will be making one of these cables tonight so that I can transfer programs from my PC to the HX-20.
1 – Signal Ground (SG)
2 – Transmit Data (TXD)
3 – Receive Data (RXD)
4 – Request to send (RTS)
5 – Clear to Send (CTS)
6 – Data Set Ready (DSR)
7 – Data Terminal Ready (DTR)
8 – No Connect (NC)