Hi and thank you for your post.
Correct me if I have misunderstood your question. You are trying to have more then one device running on PicoScope at the same time? This is not possible, however you can do this on PicoLog software by selecting multiple converters button.
The ADC10 (or indeed any of our parallel ported products) will not work with a standard Parallel to USB adapter , we have a Pico Parallel Port adapter especially designed to work for our products and only our products, please have a look at the link below:
Hope this helps