HP 41 "other" uses


We all know the 41 series had a distinguished career aboard the Space Shuttle. A custom-made ROM was developed by NASA for it. Should be a great addition to any collection if available.

I just found out that the 41 series, as well as the 71 series, had military uses as well. Someone even posted not long ago about his 71 with military applications modules. Does anybody know about these uses in the 41/71 series or about the modules produced for them?

Thanks in advance.


Well, because they are trapezoidal in shape, you could probably use one as a doorstop...



I don't know anything about specific uses, but in a lot of calculators I recently acquired, there was an HP71B with some of the military ROMS mentioned before and also a TI59 with a Library Module and instruction card with similar military markings. The keywords on the instruction card suggest an inventory control function.


The HP71 was used by the army for calculating trajectories for a lot of their field artillery and tank guns. There are ROM modules for various guns.

There is also the ever useful "Air Blast" module for calculating the effects of nukes exploding in the atomosphere. It is an HP41 module. I don't think there was a "Ground Blast" module...


If there is such an "air blast" module, does someone know where I might be able to aquire one?



I am also interested in the "air blast" module for the 41. And the others for the 71. Available, maybe, at surplus stores/depots? Or from former users?

A great addition to any collection, indeed.


There is definitely a "Air Blast" module, one was in an HP41CV that I purchased a while back. It had a quick reference card also. It is labeled "Air Blast" not "Air Burst". Now, if I can only find couple of nukes to test it with... they don't seem to show up on Ebay very often ;)


I didn't mean to confuse the issue regarding Air Blast v. Air Burst. Back when I took the Army's 2 week nuke course (pre-HP-41) they called it an air burst. So if it says Air Blast on the module, then it must be an Air Blast module B^)


I wonder about the practicality of an "Air Burst" module, oh, I don't challenge its existance, but would an HP-41 survive the ElectroMagnetic Pulse (EMP) of an air burst?
I don't think so...


There was a hard case imported from the UK, made for NATO, that was sold by EduCalc that was advertised as being able to survive and protect the 41C/CV/CX from an EM bast.


Hmmm, Thanks! Did NASA harden the space shuttle HP-41's for cosmic radiation?


Once I saw a US mortar crew using an HP-41 in the "battle case," as it was known back then. Thankfully I got some pictures from a fellow member of the Forum.

By the way, back in the 1970s and 1980s, the Russians built their bombers' electronics with sort of an "outer core" of vacuum tubes, and an internal core of microchips. Both operated jointly, and the vacuum tubes were supposed to block the Compton effect radiation of the EMP that would fry the chips. A rough but usable solution. Western bombers had different protective systems, based to some extent on the battle case, but less is known about their electronics package protection.

Ren: I read that the 41 was slightly modified for zero-gravity operation aboard the Space Shuttle. The whole story is in a link on a message thread about two weeks old.


> Ren: I read that the 41 was slightly modified for zero-gravity operation aboard the Space Shuttle.

Low pressure, not zero gravity. They removed some parts (e.g. rubber feet) that would outgas in the low pressure regime of the shuttle.

Unlike the Apollo craft where the cabin could be vented into space (for EVA - since they did not have an airlock), Shuttle electronics only need to survive the low pressure that is used for pre-breathing before EVA.

I do wonder about the HP-65 that flew on Apollo era hardware for the Apollo-Soyuz docking. Was that spec'd for vacum?



Hi (Hey, Vassilis; where've you been?)

Just wondering: any different LCD construction/material? Would ordinary LCD resist a low-preassure environment?

About the 65, I wonder about the card reader. Any special care about the rubber puller (same outgas situation) and the mechanics (dust)? Or it was also removed?


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