Promlink and DATA I/O 29b with Unipak 2 question...

Hi all, Does anyone use Promlink with DATA I/O 29b with Unipak 2 (or a similar setup)? I have a very simple question. How do I 'LOAD DATA FROM HOST'? I have a serial connection to the programmer and I can program PROMs, but when I try to read them I am told that the 'HOST PORT CANNOT BE THE SAME AS THE PROGRAMMER PORT' But I only have one serial port, and if I change things around then It doesn't work because I'm trying to communicate through a port that is not connected to anything!!! Is the serial link to the 29b only one way? My 29b has only one serial connector on the back, but also a hole (presently covered) which looks like a place for another connector. Do I need to somehow install another serial port on the 29b, or is there some setting that I am overlooking? Anyway, I'm confused. Any help would be greatly appreciated. Phil