HP-41 Quiz (big, contains pictures)



#4

Recently, I stumbled across a strange HP-41CV. It has no LCD display, the battery compartment is closed with a fawn cover, and on the side, there is a cable with a plug at the end (labeled 82106A memory module):

After thinking some minutes what this device is all about, I found the solution. It is a .... STOP. I know the folks here likes quiz games :-) And this one is not too difficult. But the only prize I can offer is a picture of the inside of this device.

Enjoy, Juergen


#5

Hi Juergen,

Okay, I'm game - here's two guesses:

1. Ports expander.

2. Memory expander.

Bill

#6

(semi)-remote keyboard?

#7

OK, Here's what I think we know:

  1. Fawn colored cover on the back where the batteries go
  2. Cable emerging from AC power port
  3. No display
  4. Cable terminates in a module reading "82106A"

OK, so #1 #2 and #3 clearly point to a homebrew project of some kind. In light of that, #4 is a red herring, since a hacker could implement just about anything inside an 82106A case. (Hi, Diego!) #3 clearly implies that processing for local consumption is not a feature of this device. #2 says the same thing. So what's inside the box that could be a resource for an external 41C? Probably not another 41C. I doubt the 41C electronics would be happy running without an LCD, so I'd guess that the case is just an enclosure for something.

What could that be? Well, if you replace the PCBs, practically anything. But what is a 41C case good at holding, other than the PCBs, keyboard etc? Ah, the modules. You haven't shown us the ports, have you? 8)

Regards,
Howard


#8

I thought of a second processor thing, like the Acorn BBC used to support, but on second thought I also bet on a port replicator.

But then, why would the LCD have been removed?


#9

Because the PCB is gone, not just the display?

#10

Two guesses I know, that's cheating ;)

1) using the 41 "framework" (electronics removed) as a cheap keyboard
2) using the 41 with a speaker box instead of a display for blind people

#11

It doesn't do anything. You see it, you get curious, you open it up, and a spring snake jumps out. 8^)

#12

Thank you all for your guesses which show, on the one hand, your expertise and, on the other hand, your
good sense of humor. I enjoyed the ideas of remote keyboard, dual-core 41, 41 for the blinds, etc.
Now it's time to disclose the secret (well, it's not so secret anymore; you already found the solution):
it is a port replicator. when opening the calculator, I saw that there was no PCB, too:



This might mean a second life for many "cannibalized" HP-41. Unfortunately, I cannot open the
plug because it is glued and I borrowed the calculator from a friend of mine. Thus I cannot
provide the exact connections but probably they can be deduced from information in the HP-41
service manual.

Best Regards,
Jürgen


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP-41(CL): The easiest way to transfer FOCAL programs from a Linux PC to the HP-41 Geir Isene 13 1,296 12-05-2013, 02:40 AM
Last Post: Hans Brueggemann
  OT--Found!!! An HP reference on 'The Big Bang Theory' Matt Agajanian 0 270 11-08-2013, 10:23 PM
Last Post: Matt Agajanian
  HP-80 Teardown with pictures Max Stone 10 943 10-24-2013, 09:10 PM
Last Post: Walter B
  DIY543 pictures Richard Ottosen 93 4,826 10-22-2013, 08:04 AM
Last Post: Cristian Arezzini
  OT--'The Big Bang Theory' and RPN/HP--Any connections? Matt Agajanian 19 1,261 09-05-2013, 08:27 AM
Last Post: Adrien Bertrand
  RPN-1200 (with pictures) Benoit Maag 12 985 09-02-2013, 06:09 PM
Last Post: Matt Agajanian
  HP Prime pictures with video ! Mic 55 2,634 06-24-2013, 02:52 PM
Last Post: CompSystems
  New pictures of HP Prime in hand Mic 52 3,321 06-15-2013, 10:15 PM
Last Post: Peter Murphy (Livermore)
  New screen on pictures of new Sharp EL-9950 Mic 4 516 06-10-2013, 10:40 AM
Last Post: Mic
  HP-65 Repair/Restoration (Pictures) :) Dan Lewis 8 745 01-12-2013, 12:41 AM
Last Post: Dan Lewis

Forum Jump: