A mistake that made me very happy. :-) :-) :-)

[hp41cx]

Can you find out the reason for my happiness?

[Maximilian Hohmann]

Hello!

(11-14-2018 11:53 AM)hp41cx Wrote:  Can you find out the reason for my happiness?

First it's an HP-41C and not CV as in the description, so if you were missing one of those in your collection that might be a reason for your happiness and second, it might, contrary to the description, actually work!

Regards
Max

[hp41cx]

(11-14-2018 12:21 PM)Maximilian Hohmann Wrote:  Hello!

(11-14-2018 11:53 AM)hp41cx Wrote:  Can you find out the reason for my happiness?

First it's an HP-41C and not CV as in the description, so if you were missing one of those in your collection that might be a reason for your happiness and second, it might, contrary to the description, actually work!

Regards
Max

Yes 41C but pay attention that's not the only reason for my happiness ;-)

[Didier Lachieze]

Early S/N: 1926A00255

[hp41cx]

(11-14-2018 12:47 PM)Didier Lachieze Wrote:  Early S/N: 1926A00255

Yes!! Yes!! Yes!! :-) :-) :-)

Only 254 were made before my 41C!
Am I right?

[Didier Lachieze]

(11-14-2018 12:52 PM)hp41cx Wrote:  Only 254 were made before my 41C!
Am I right?

Only 254 with S/N 1926A, but there are reports of units with an earlier S/N 1916A.
Anyway it's a very early unit and a very good mistake.

[hp41cx]

(11-14-2018 01:02 PM)Didier Lachieze Wrote:  

(11-14-2018 12:52 PM)hp41cx Wrote:  Only 254 were made before my 41C!
Am I right?

Only 254 with S/N 1926A, but there are reports of units with an earlier S/N 1916A.
Anyway it's a very early unit and a very good mistake.

but Known "Prototype's:"

1916 A 00066
1916 A 00076

[CY-CL]

Sorry:

The HP-41C Calculator you bought is not a real early one. Just the backside comes from an early one. The keyboard side is from a newer C, probably from a 21xx one.

Why?: The keyboard from an early one has the Tall Keys and a complete other structured front panel.

The value from an early 1926 depends also from a fully functionally CPU board which contains ALL known bugs.

Regards,
Patrik

(11-14-2018 11:53 AM)hp41cx Wrote:  Can you find out the reason for my happiness?

[CY-CL]

LEFT early Keyboard ... RIGHT newer Keyboard

[rprosperi]

(11-14-2018 01:02 PM)Didier Lachieze Wrote:  ...but there are reports of units with an earlier S/N 1916A.
Anyway it's a very early unit and a very good mistake.

The unit RJN has, noted by Diego, is confirmed, 1916A0078. After some effort this past weekend, I was able to get it working again; this is the first time it has worked since the 80's so the recovery was surprising and also real satisfying. Unfortunately the unit had been speeded-up in the past, and though it does work fine at about 1.4X normal speed, the speedup method installed (adding a cap) prevents use of the ports (presumably due to increased bus speed). IIRC, and maybe I don't, there were some 41 speedups installed that had a micro-switch allowing user to 'switch back to normal speed' to allow use of ROMs, HP-IL, etc. but this particular unit did not have this feature.

Anyhow, nice catch hp41cx! Once you receive it, let us know if it works (it will likely need some post repairs). Thanks for sharing this find.

[hp41cx]

(11-14-2018 02:16 PM)CY-CL Wrote:  LEFT early Keyboard ... RIGHT newer Keyboard

Rom DDE
BUG 1,2,3,4 are confirmed :-)

[Archilog]

Hi! Congrats for this purchase, HP41CX.

I have bought to this seller a HP-29C last week, but didn't notice this 41, lucky man!

[David Hayden]

(11-14-2018 02:16 PM)CY-CL Wrote:  LEFT early Keyboard ... RIGHT newer Keyboard[/size]

This may be heretical, but I don't see the difference. What am I missing?

Regarding the S/N's. I thought the last 4 digits indicates the unit number for that week only. So this would be #255 made it week 26 of 1979.

[grsbanks]

HP weren't always 100% diligent in changing the serial number prefix every week and would often only do so either when there was a design change or when they ran out of numbers to the right of the country code.

Case in point, there's a metric buttload of HP35 units in the wild with a serial number that starts with "1143A"

[burkhard]

(11-15-2018 03:30 PM)David Hayden Wrote:  

(11-14-2018 02:16 PM)CY-CL Wrote:  LEFT early Keyboard ... RIGHT newer Keyboard[/size]

This may be heretical, but I don't see the difference. What am I missing?

To me, the keys themselves both look like the earlier "tall keys", but it is hard to tell since the photo angle is so steep. I agree they seem the same, though.

I think the difference is in the finish of the field *around* the keys. The one on the left is smooth, while the one on the right is a bit pebbled, which would better mask dirt and small scratches.

I presume the one on the right is the later design—it matches the HP41 calculators I have.

Now, the one that hp41cx purchased appeared to me to have both short keys (again, though, the angle in the pix can be deceptive) AND the pebbled "key surround" or whatever you call it.

[CY-CL]

Yes this picture shows two version of Tall Keys, is just an example to show the difference from the front panel, not the Keys.

Three keyboards was available during the years for the HP-41C

1. Tall Keys with shining front panel - 1916 up to 1952
2. Tall Keys with structured font panel - 2001 up to 2052
3. Newer Keys “shallower angle” with structured front panel 2101 up to end of production

If he wants a period correct calculator, he needs another front panel from an early HP-41C.

(11-15-2018 04:27 PM)burkhard Wrote:  

(11-15-2018 03:30 PM)David Hayden Wrote:  This may be heretical, but I don't see the difference. What am I missing?

To me, the keys themselves both look like the earlier "tall keys", but it is hard to tell since the photo angle is so steep. I agree they seem the same, though.

I think the difference is in the finish of the field *around* the keys. The one on the left is smooth, while the one on the right is a bit pebbled, which would better mask dirt and small scratches.

I presume the one on the right is the later design—it matches the HP41 calculators I have.

Now, the one that hp41cx purchased appeared to me to have both short keys (again, though, the angle in the pix can be deceptive) AND the pebbled "key surround" or whatever you call it.

[Paul Berger (Canada)]

(11-15-2018 04:55 PM)CY-CL Wrote:  Yes this picture shows two version of Tall Keys, is just an example to show the difference from the front panel, not the Keys.

Three keyboards was available during the years for the HP-41C

1. Tall Keys with shining front panel - 1916 up to 1952
2. Tall Keys with structured font panel - 2001 up to 2052
3. Newer Keys “shallower angle” with structured front panel 2101 up to end of production

If he wants a period correct calculator, he needs another front panel from an early HP-41C.

I have a tall key with a shining front panel and a serial number starting with 2010.

Paul.

[Zaphod]

Quote:think the difference is in the finish of the field *around* the keys. The one on the left is smooth, while the one on the right is a bit pebbled, which would better mask dirt and small scratches.

Looks to me like the left one is a painted and printed aluminium plate and the textured one on the right is a self adhesive printed plastic sheet.

[burkhard]

(11-15-2018 05:54 PM)Paul Berger (Canada) Wrote:  I have a tall key with a shining front panel and a serial number starting with 2010.

Troublemaker.

[aurelio]

(11-15-2018 05:54 PM)Paul Berger (Canada) Wrote:  

(11-15-2018 04:55 PM)CY-CL Wrote:  Yes this picture shows two version of Tall Keys, is just an example to show the difference from the front panel, not the Keys.

Three keyboards was available during the years for the HP-41C

1. Tall Keys with shining front panel - 1916 up to 1952
2. Tall Keys with structured font panel - 2001 up to 2052
3. Newer Keys “shallower angle” with structured front panel 2101 up to end of production

If he wants a period correct calculator, he needs another front panel from an early HP-41C.

I have a tall key with a shining front panel and a serial number starting with 2010.

Paul.

I have just checked and I have three tall keys with shining front panel, two of them not matching the rules:
1951
2004 (!)
2043 (!)

I'm not the first owner so that I don't know exactly their whole lives....but which interest, if not originals, in swapping the back side?
It should be more justified maybe the opposite..... after a servicing, i.e. the swap of a faulty keyboard