Was gifted some old HP's today... questions

[tppytel]

Yes, the 15C was the one I mentioned above. Mark made a generous offer, so I sold it on behalf of my friend and am passing the funds back to him. I'm keeping the 10C for my own use. I tried to pay my friend for that but he wouldn't accept it - he just asked me to buy our math team kids nicer pizza at their next party.

He still has that 28C if anyone's interested. I know it's not as popular as the Voyagers but it does have two manuals and all four application books, which might be of interest to collectors. We didn't have any N-cells handy to test it out, though.