[philposting]

Anyone know why it was called the HP-35 if it was the first?

[Pinus]

The usual explanation is that it’s got 35 buttons. Whether that’s the true reason I don’t know, but at least the button count checks out!

Now, if someone could explain to me the logic behind the naming of the HP-10, HP-10b, HP-10C and HP-10s, I’d be most grateful...