HP-35 accessories


A co-worker cleaned out his parent’s basement and gave me an HP-35 calculator. This was the calculator I couldn’t afford as a student (72-75). Also a great addition to my slide rule collection considering this was the calculator that ended the slide rule era.

Thanks to the repair tips on this site I was able to find the hidden screws, open and remove the gunk from the on-off switch. I should have a replacement battery pack assembled later this evening.

My question is what accessories came with the calculator? I have a gray-blue box, manual and charger. Was the black (leather?) case a separate item? It doesn’t look like it would fit in the gray-blue box.


(Looks like I posted this question to the forum. 2X!! Mayber 3X is this attempt fails. Apologies. I hope someone with authority will delete it. Thanks.)

Edited: 12 Jan 2005, 6:40 p.m.



AFAIK the leather case was tightly rolled,

to fit into the space nearby the charger.

Aside from the manual, there was a small

cardboard sheet showing accessories,

the guarantee/warranty card and a sheet

of paper about the batteries.



There were a few applications books with keystroke sequences for various professions. These are the bare bones. You will find some of the same routines from the surveying books, for instance, as the heart of the HP programs for the 65, 67 and 41 You can get scans of all the known books by buying the museum cd/dvd.


There were two hardware accessories which did not come in the package with the HP-35:

The Reserve Power Pack (82004A)provided the capability to have a spare battery pack charging while the calculator was in use.

The Security Cradle was used to prevent the calculator from "walking away". That was not an inconsequential problem in those days. The company where I worked purchased several calculators. They soon disappeared. When replacements were purchased the users were required to use security cradles which provided the capability to lock the calculator in the cradle which was bolted to the user's desk or tied to the desk with a security cable. This had the unhappy effect of turning a portable calculator into a desktop calculator.

The cradle in my collection carries the stock number 82007.


HP made a thick black leather field case (along with the glove leather one) that would fit on a military web belt too. I crammed my 41 into one for a while but it was really for the 35/45. I just thought of the 35's applications manuals first because they are such clean keystroke examples, and useful to someone who is finally retiring his slip stick and moving up to a 35 :-)


Thanks for all of your responses. I built a replacement battery pack and the calculator is up and running. The main missing accessory seems to be the (leather) case.


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