HP50g serial communication with 3rd party device

[Marakasmalan]

Think I got the problem:

From the device's manual:
"Pin Function
• 2 Transmit Data
• 3 Receive Data
• 5 Signal Ground

This pinout allows the NAD product to be connected to a PC with a standard straight throw serial cable."

To connect the hpcalc.org serial cable to a pc, a null modem adaptor is required. I will aquire this today and try again!

Thank you for all the help