Hi, I see there is an HP 5181A on eBay: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7521170381 This looks exactly the same as an HP 9915A (the industrial version the HP 85A, part of the series 80), does anyone know please what the differences are? Sadly this one does not have the console interface for a keyboard and screen, but I guess it has additional software. Also it is shown bolted to an OX-Y display, but as there are no leads there is no clue there. Any suggestions please? Regards, John