The HP-12C [PDF] is a remarkably long-lived financial calculator from Hewlett-Packard (HP). It first appeared in 1981 and has continued in production ever since, with just the odd tweak here and ...

Earlier this week, we told you about Wall Street's geek obsession with the HP 12c financial calculator, a 30-year-old staple for number crunchers. Readers have sent in photos of their nerdulators ...