How to display CAT1 with HP 82163

[hpcalcuser83]

I have a HP 82163 HPIL Video Display (40 col). I have an HP-41C as the HPIL controller with the only device in the loop being the 82163. I can display the X-reg via PRX command, I can display the Alpha reg with the PRA command, but I cannot get the CAT1 to display when I execute a CAT1 command on my HP-41C. The CAT1 information is displayed on the HP-41C LCD display, but not on my video display. I reviewed the manuals, but do not see what I am missing. Do I need to issue some command prior to a CAT1 to see the CAT1 information on the video display?