This is a unit that I have never run into before. If anyone knows what it was used for please shoot me a message. Unit is very heavy and has card banks on both front and back. I have not been able to find an actual HP number that I can find any research data on. I have found dates on cards from 6/11/99 to 02/04/00. If you look closely at pictures you can see some of the circuit board numbers. Unit comes with some spare boards as shown in one of the pictures. I would prefer selling as a unit, but if you see a specific board you need, please message me and I will consider parting unit out. Inquire if shipping is a requirement and I can get an estimate to your location.