HP-35: The first HP pocket calculator and the world's first scientific calculator, this particular model is the fourth of four designs. It is distinguished by key legends that are molded into the keys rather than printed on the keyboard--and thus will never rub off with use. The HP-35 was introduced in 1972 at a cost of $395. 31 years later, it still works fine with an AC adapter--the rechargeable battery pack has, however, held its last charge. Early HP calculators were noted for RPN logic, using an ENTER key rather than an = key for arithmetic operations.
1. HP-21: An earlyish scientific HP.
2. HP-67: Magnetic card programmable model; top of the HP line in the mid-70's. The three shift keys (f, g, and h) mean that most keys have four separate functions.
HP-97: A larger printing version of the HP-67 with fewer (1: f) shift keys.
HP-38C and HP-38E: These two financial calculators are identical except for the continuous memory on the 38C. Both perform a host of standard financial calculations.
1. HP-45: A scientific calculator which was given to me by the
College Department of Physics. This is the first HP calculator
with a shift key (yellow) to allow keys to perform multiple functions.
2. HP-41CV: An extension of the HP-41 line of alphanumeric scientific calculators. This one has a removable face plate installed, primarily because it photographs well.
1. HP-10S: A new-order business calculator with (gasp!) algebraic
2. HP-20S: A scientific calculator with algebraic logic.
1. HP-6S: A scientific algebraic model in metallic blue.
The 6S Solar has a white face and a solar panel.
2. HP-30S: One of HP's newest machines, this one comes with interchangeable faceplates in gray and aqua in addition to purple.
HP-12C: Very close to being the financial industry's standard calculator.
HP-12C Platinum: While the standard 12C, introduced in 01981, is still a top-seller, Hewlett-Packard updated some of its functions and power in 02003 as they began the release of seven new calculators designed to reestablish the HP line. This calculator includes algebraic entry as an option.
HP-18C Business Consultant: This notebook-format financial calculator includes an electronic datebook. It was introduced later than, but failed to supplant, the 12C.
HP-28S: Hewlett-Packard's first graphing calculator, in the notebook format with an alphabetic keyboard to the left. This calculator is on permanent loan from the Albion College Department of Mathematics and also does symbolic manipulation.
1. HP-38G: A later graphing calculator. It's showing the
simultaneous graph of all six basic trig functions (this calculator has secant,
cosecant, and cotangent as separate functions).
2. HP-82240A Printer: This printer uses infrared technology to print information from several HP machines, inlcuding the 18C, 28S, and 38G shown here.
Larger picture for better detail, showing part of its menu-driven system.
HP-48G: A more recent graphing calculator, this one showing my favorite function, f(x) = etan(ln x), on the interval (0,1].
HP-33S: A scientific calculator released in 02004 as part of the new line of HP calculators, this one is distinctive in styling but suffers from a design flaw or two. Note especially the tiny decimal point, which has been the target of much criticism in the collectors' community.
Not yet pictured: HP-6S Solar.