Enter key The HP-35


Introduced on the 1st of July 1972, discontinued the 1st of February 1975.
In total about 300.000 HP-35 calculators were sold. The HP-35 borrows its model name from its number of keys.

Four different production versions of this model are known.


Version 1

The first production version had a red dot to the right of the power switch to indicate that the calculator is switched on.
This model is hard to get ( and therefore really expensive) and unfortunately not a member of my collection.


Version 2

Version 2 has no red dot and the text "HEWLETT • PACKARD" is labeled on the front side. Early models of this version 2 have a raised dot on the "5" key. Later version 2 models this raised dot was dropped. The calculator shown on the photo below has this dot. See the insert on the right bottom.


The serial numbers did not follow production date exactly in that time. For a lot of these calculators the serial started with 1143A or 1230A.


Version 3

Version 3 is almost identical to version 2 but has the text "HEWLETT • PACKARD 35" labeled on the front side.



Version 4

Version 4 is the final version of the HP-35 model and can be recognized by all the key legend molded into keys in stead of printed above the keys.


The size of the keys on the first four rows has been enlarged. These keys are no longer square shaped. The ON OFF text near the power switch is molded into the plastic instead of printed.


Backside instruction label

The label is glued on the backside of the HP-35 calculator. This label was printed in more languages.

HP45 Instructions backside

Below backlabel in Dutch.

Backlabel dutch


Owner's Handbook

A small manual was included. The cover shows the version 2 model.

Handbook HP45




Plastic Travel Case

The HP-35 was sold in a nice plastic travel case. This case also contains the battery charger HP 82010A and the manual.

HP35 case

The picture below shows the label on the travel case

HP35 Case label


A nice JavaScript HP 35 emulator can be found on my emulator page.
My HP-35 inside page show some inside pictures of this Classic model.


HP-35 related links: