HP-28S with User and Advanced Reference Manuals

[revwillie]

I got a 28c for $40 on ebay last year. Maybe I was just lucky, but the battery door is pristine and it was very clean all around. The seller had installed new batteries. I opened the battery door just out of curiosity, but I'll resist the temptation moving forward. Personally, I prefer the 42s for ease of use. RPL is obviously powerful, but there's a learning curve. $150 is a fair price for a 28S if it is still like-new. Also, it looks like manuals are harder to find and DanLewis was including two original manuals.

Was the 28c the first hand-held graphing calculator?