I purchased 4 HP-85Bs at auction yesterday. I was browsing information on HPs at http://www.finseth.com/~fin/hpdata/serial.html, and discovered that one of my "new" machines was manufactured in February, 1982. That's 16 months before the 85B was released, as I understand it. Here's the serial number: 2210A60158. If the first two digits are the number of years since 1960, it was manufactured in 1982. If the next two are the number of weeks since a certain week in November, it was manufactured sometime in February. Is that right? If the HP-85Bs were released on June 1, 1983, this one was either a prototype that rolled off the 85A assembly line, or it's an 85-A in disguise. Do the 85B covers fit the 85A? If so, there's a hapless soul with an 85B that thinks it's an 85. And I own both models. Something else that's interesting: This particular model had an older-style riveted-on serial number plate, while the other three had newer stickers. It s also the only one with a 82936A ROM DRAWER. This drawer has the 00085-15002 PLOTTER/PRINTER ROM. I don't think that's significant, but maybe?? One other thing: The FCC-ID on three models ends with 85B. The model in question either hasn't got one, or I can't find it. If you can shed any light, please do so. I plan to keep one and sell off the other three. If I'm selling an 85-A, I want to make sure that's what I'm advertising. In fact, I may just want to keep two of them. Also, how much is an 85-A worth? I can't find them for sale anywhere. Cheers, John