older HP calculators

[Katy Brocksmith]

I bought two calculators from an instructor. For sure, one is a 28c---it opens kind of like a book with a spine.

Does anyone know if there was ever another calculator that had such a "spine" as a connecting tool to hold two pieces together?

I'm trying hard to remember what the model name was for the other calculator I bought. By the way, this event goes back to 2001 which is why I'm so foggy about the situation.

Much thanks,
katyb

[SlideRule]

GOOGLE® HP Champion series calculator

18c
19b
19b II (3 variants)

28c
28s

for HP folding models

however, for the sake or full inclusion, other manufacturers also marketed folding {w/ a central spine} calculator(s), both horizontal & vertical.

BEST!
SlideRule

[striegel]

If you want to really appreciate them, you have to see the beautiful images Keith Midson took at https://www.flickr.com/photos/keithmidso...020558518/


Alan