HP 41 - Strangeness

[GentlemensVintage]

Hello all. I am brand new to the forum and a huge HP Calc fan since my first encounter with a 19B in the late 1980s.

I recently acquired this 41CX and I am baffled by it. I think it is a CX due to the serial number (2744@20155) Do you notice anything odd about the keyboard? The keys are missing the printed functions. I have never seen this on an HP. Also, the bottom of the calculator where it would normally have the model number only shows Hewlett Packard and the Logo displayed. See the pics. I would love to hear if any of you have seen this on a HP Calc before or can shed any light on this calculator.

https://drive.google.com/file/d/1HYChkFH...sp=sharing
https://drive.google.com/file/d/1ZnoUjtr...sp=sharing
https://drive.google.com/file/d/1vycgeYq...sp=sharing

Happy Holidays,

Will

[smp]

From the MoHPC:

http://www.hpmuseum.org/hp41.htm

"Differences between the C, CV, CX and Option 001

The HP-41CV was the same as the HP-41C except that it had four memory modules built in for a total of 319 registers. (With the four ports still available to add other modules.) The HP-41CX was the same as the HP-41CV but added the Time module (stopwatch plus clock with alarms), an Extended Functions / Extended Memory module, a text editor, and some additional functions. The Option 001 version of the HP-41C had no labels on the upper rows of keys or on the surrounding keypad. This version was meant to be heavily customized by the buyer."

Merry Christmas!

smp

[Thomas Okken]

That type, officially called "Option 001" but more commonly referred to as a "blanknut" in this forum, was made for customers who wanted to run special-purpose software on it, using keyboard overlays to indicate the keys' functions. Apart from the missing legends, it is a regular 41.

I don't know which of the 41C, 41CV, and 41CX were made as blanknuts, but you can tell them apart easily: first, with the calculator off, remove all modules (if any are inserted in the expansion ports at the top end of the calculator), then turn it on while holding the left-arrow key. You should see MEMORY LOST in the display. Then, type [RCL] [1] [7]. If it says NONEXISTENT, it's a 41C, else it's a 41CV or 41CX. To tell the difference between CV and CX, press [Shift] [CATALOG] [2]. If it's a 41CX, four items should be shown: TIME 2C, CX TIME, EXT FCN 2D, and CX EXT FCN; if it's a CV, the catalog will be empty.

(Updated because of errors in how to tell apart 41C and 41CV.)

[Sylvain Cote]

HP produced these HP-41 variant over the years

Code:

-------------------------------
     | FN | FN | FN | HN | HN | 
     | TK |    | BN |    | BN |
-----+----+----+----+----+----+
41C  | xx | xx | xx | xx | -- |
-----+----+----+----+----+----+
41CV | xx | xx | xx | xx | xx |
-----+----+----+----+----+----+
41CX | -- | xx | ?? | xx | xx |
-------------------------------

Legend:

Code:

FN = full-nut
HN = half-nut
TK = tall-keys
BN = blank-nut
xx = produced
-- = never produced
?? = not sure, never seen one

Here is an old picture (2014) of some of my HP-41's: picture
Since then, I was able to these ones 41C-FN-BN, 41CLv4 & 41CLv5 to the collection.

edit: following Ignacio post, added 41CV-FN-TK

[GentlemensVintage]

A "blanknut", I love it! I believe I have found my home at MoHPC.

@smp, thanks for the details.

@Thomas Okken, thanks for the commands to identify. The result is...CX.

@Sylvain Cote, can you tell from my pics what CX variant mine is?

[Jlouis]

(12-24-2018 12:52 AM)Sylvain Cote Wrote:  Here is an old picture (2014) of some of my HP-41's: picture
Since then, I was able to these ones 41C-FN-BN, 41CLv4 & 41CLv5 to the collection.

Hi Sylvain,

I've noticed some displays are darker than others. Is there any real difference or it is some kind of light effects?

Cheers

[Paul Berger (Canada)]

(12-24-2018 01:25 AM)GentlemensVintage Wrote:  A "blanknut", I love it! I believe I have found my home at MoHPC.

@smp, thanks for the details.

@Thomas Okken, thanks for the commands to identify. The result is...CX.

@Sylvain Cote, can you tell from my pics what CX variant mine is?

The CX variant you have there is the halfnut the telltale indicator is the rounded corners in the display.

Paul.

[Sylvain Cote]

(12-24-2018 01:44 AM)Jlouis Wrote:  I've noticed some displays are darker than others. Is there any real difference or it is some kind of light effects?

No real differences, just poor lighting and not that great phone camera when I took the picture four years ago.
Sylvain

[rprosperi]

(12-24-2018 12:52 AM)Sylvain Cote Wrote:  Here is an old picture (2014) of some of my HP-41's: picture
Since then, I was able to these ones 41C-FN-BN, 41CLv4 & 41CLv5 to the collection.

Do you (or does anyone else) know for sure if all BlankNuts originally came with the 'shield/cover' that covered the USER and PRGM keys? Today, most BN's have lost them, but I've never known for sure if they all were sold that way, or if there were 2 types of BNs sold, with and without the shield/cover.

[Sylvain Cote]

(12-24-2018 04:27 AM)rprosperi Wrote:  Do you (or does anyone else) know for sure if all BlankNuts originally came with the 'shield/cover' that covered the USER and PRGM keys? Today, most BN's have lost them, but I've never known for sure if they all were sold that way, or if there were 2 types of BNs sold, with and without the shield/cover.

Robert,
Two of my blanknut's came with the USER/PRGM cover while the others did not.
FYI, the cover is very easy to install and remove.
I am not sure, but I would think that the cover was part of the kit at first and it's possible that at some point HP decided to no longer include it.
That or it was always included and people decided to not install it on the machine or just lost it.
Sylvain

[isanchez]

(12-24-2018 12:52 AM)Sylvain Cote Wrote:  HP produced these HP-41 variant over the years

Code:

-------------------------------
     | FN | FN | FN | HN | HN | 
     | TK |    | BN |    | BN |
-----+----+----+----+----+----+
41C  | xx | xx | xx | xx | -- |
-----+----+----+----+----+----+
41CV | -- | xx | xx | xx | xx |
-----+----+----+----+----+----+
41CX | -- | xx | ?? | xx | xx |
-------------------------------

Legend:

Code:

FN = full-nut
HN = half-nut
TK = tall-keys
BN = blank-nut
xx = produced
-- = never produced
?? = not sure, never seen one

Here is an old picture (2014) of some of my HP-41's: picture
Since then, I was able to these ones 41C-FN-BN, 41CLv4 & 41CLv5 to the collection.

Hi,
just to add that I have a couple (2) of HP41CV tall keys (TK) full nut (FN). Not result of repairs...they are nearly consecutive serial numbers...bought from different owners and both in Spain....rare, I suppose.

Merry Christmas and happy New Year.

Regards

Ignacio

[Sylvain Cote]

(12-27-2018 09:27 AM)isanchez Wrote:  Hi,
just to add that I have a couple (2) of HP41CV tall keys (TK) full nut (FN). Not result of repairs...they are nearly consecutive serial numbers...bought from different owners and both in Spain....rare, I suppose.

Merry Christmas and happy New Year.

Regards

Ignacio

Hello Ignacio,

First time I hear that a HP-41CV was ever made as tall keys, great find!

I would appreciate if you could you post the first part of the serial number (YYWWC) of these units.

Best regards,

Sylvain

PS: if at some point, you decide to sell one or both of them, I am a buyer.

[isanchez]

Hi,

no problem at all. Even more, I enclose some pictures, including the sn (no problem with that). This is one of the CV tall keys, the other is at home, but it is three or four sn numbers around. Can't remember exactly.

Both are in pristine state, with box and extras...I bought them in different times at different cities in Spain.

I do not believe they can be considered as "produced", because they are exceptional, in the sense of not "regularly produced", I believe...so your diagram can be considered right....

I take note of your kind offer, but no intention to sell for the moment.

Talking about "strangeness" in HP41 series, I also have an early HP41C, made in Brasil, with a sn where the figure for the weeks exceeds 52...it says 54, I believe by heart (I do not have in my hands now, but I can check it at home)...maybe time passes in Brazil more joyfully, so years seem to exceed 52 weeks ;-D


Regards

Ignacio

(12-27-2018 01:15 PM)Sylvain Cote Wrote:  

(12-27-2018 09:27 AM)isanchez Wrote:  Hi,
just to add that I have a couple (2) of HP41CV tall keys (TK) full nut (FN). Not result of repairs...they are nearly consecutive serial numbers...bought from different owners and both in Spain....rare, I suppose.

Merry Christmas and happy New Year.

Regards

Ignacio

Hello Ignacio,

First time I hear that a HP-41CV was ever made as tall keys, great find!

I would appreciate if you could you post the first part of the serial number (YYWWC) of these units.

Best regards,

Sylvain

PS: if at some point, you decide to sell one or both of them, I am a buyer.

[attachment=6701][attachment=6702][attachment=6703][attachment=6704]

[hth]

I have a slightly higher serial on my CV, 2103A10346 and it has the slanted keys. My unit had the keyboard replaced around 1982/83, but it also had the slanted keys before.

[Sylvain Cote]

Wow! very nice unit thanks for the pictures.
Yeah, week number 53 & 54 has been mentioned here before, some linked it to moon cycles (for 53) but I am not very convinced of this.
Regards,
Sylvain

[aurelio]

(12-27-2018 01:15 PM)Sylvain Cote Wrote:  PS: if at some point, you decide to sell one or both of them, I am a buyer.

I'll be the second (if I'll win the lottery)
Whow Ignacio, very beautiful and very "strange"

[CY-CL]

The MoHPC collector corner says, the first HP-41CV is probably produced at ~2040. (1980 40th Week).

Officially the CV was introduced on 15th December 1980, this would 2051, regarding the fact, that calculators were produced around one month in advanced, the date 2040 would realistic.

Why a HP-41CV with S/N 2103A10255 has Tall Keys and the S/N 2103A10346 has the Slanted Keys? (Probably the factory had still some Tall Keys Keyboard and mounted them in the first 3 weeks in 1981 until the last one was used up.)

What for keys had the early HP-41CV’s from 2040 up to 2050?

There are always exciting new facts about our HP calculator hobby. Many thanks for sharing!

[isanchez]

Hi again,

what you say (CY-CL) has a lot of sense...they probably spent some of the stock of tall keys while deploying CV "new" model and moving to slanted keys for all 41 series (C & CV).

The other CV tall keys sn is 2103A10260, this is five # over the other CV. It looks like never used.

Kind regards


Ignacio

[Massimo Gnerucci]

(12-27-2018 02:59 PM)isanchez Wrote:  Talking about "strangeness" in HP41 series, I also have an early HP41C, made in Brasil, with a sn where the figure for the weeks exceeds 52...it says 54, I believe by heart (I

My first 41C, that started all this hobby, is a 1953A...