HP 41C calculator

From: David Betz <dbetz_at_xlisper.mv.com>
Date: Wed Nov 17 11:02:21 2004

Hmmm... Maybe I should have kept the 41C after all. Oh well, maybe I'll
find a working one some day...

What makes it so much better than say an HP 48GX or even an HP 42S?

On Nov 17, 2004, at 10:58 AM, Joe R. wrote:

> At 09:37 PM 11/16/04 -0500, you wrote:
>> Thanks for all of the 41C info. I'd like to pick up a working CX
>> someday but they go for over $200 on eBay. I guess I'll have to stick
>> with my more modern HP calculators for now.
> There's a reason that used HP-41s bring over $200. The modern HP
> calculators bite! Once you get used to a 41 you'll stick to it.
> Joe
>> On Nov 16, 2004, at 7:40 PM, Tony Duell wrote:
>>>> The HP 41C is gone! It's amazing how many people wanted it even
>>>> though
>>>> it was broken. Thanks to everyone who expressed interest.
>>> I am not suprised. Most HP41 faults are just bad connections (either
>>> between the logic board and the keyboard/display or between the I/O
>>> assembly and the keyboard/display) and can be fixed easily.
>>> Corroded I/O assemblies due to battery leakage are quite common too,
>>> but
>>> they can be repaired with care and a fine-tipped soldering iron.
>>> IC failures are uncommon, but I have had the odd one. Sorting out
>>> logic
>>> failures is hard because the connections are made when the case is
>>> screwed together which means it's almost impossible to run the
>>> machine
>>> with the logic PCB exposed. HP used a special 'test calculator' at
>>> the
>>> service centres for this -- it consisted of a normal HP41 with the
>>> back
>>> case cut in half (exposing the logic PCB end) and modified
>>> pillars/screws
>>> to hold the logic PCB in place. I've never seen an official one, but
>>> making a clone was an enjoyable afternoon's work.
>>> The HP41 is still a very useful calculator. The 41C is the simplest
>>> model
>>> with 64 'registers' (a 'register' is 7 bytes...) of user memory,
>>> partitionable between programs and data. You can put up to 4 memory
>>> modules in it, each adds another 64 registers, but doing that uses up
>>> all
>>> the I/O ports. There was also a quad memory module which adds 256
>>> registers using just one port. And then there's the 41CV which has
>>> the
>>> full memory built-in
>>> The top model is the 41CX. It's a CV with extended functions (string
>>> handling, etc), extended memory (the ability to save programs and
>>> data
>>> in
>>> named files in another area of memory) and timer (clock, stopwatch)
>>> built
>>> in _and then some more functions on top of that, like a simple text
>>> editor.
>>> Add on ROM modules include things like maths, stats, circuit
>>> analysis,
>>> structural engineering, thermal science, financial, etc, etc, etc.
>>> And
>>> ssytem extensions like extended functions and timer. And 'hacking
>>> modules' (third party code, although AFAIK HP always made the
>>> physical
>>> modules) like ZenROM which let you edit the machine's memory
>>> directly.
>>> Serious hackers even made ROM emulators (using RAM rather than ROM)
>>> so
>>> they could program the 41 in machine code.
>>> And then there's the HPIL module with its extension ROMs (extended
>>> I/O,
>>> HPIL Development, always called DevIL :-)) which let you connect this
>>> little calculator to a disk drive, plotter, thinkjet printer, RS232
>>> interface, HPIB interface, video display, data logger, etc, etc, etc.
>>> And dedicated peripherals like a magnetic card reader, thermal strip
>>> printer, barcode wand.
>>> What do I have? About a dozen machines, mostly CVs, but the odd CX
>>> and
>>> the odd C (including a very early C with all the original bugs!), a
>>> couple of dozen modules, most of the peripherals, the machine code
>>> development tools, and so on.
>>> It's a great machine, and still very actively used
>>> -tony
Received on Wed Nov 17 2004 - 11:02:21 GMT

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