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Which Model HP-41C For the 41CL Transplant?
Message #1 Posted by Mark Hardman on 29 Nov 2011, 10:48 a.m.

I have nine working HP-41's to choose from. I only have a single HP-41C, so I don't want to use that one.

Of the remaining machines, one is a NIB HP-41CV that has only rarely seen the light of day. I'm tempted to use this calculator as it would likely have the longest useable life span and would be the least likely to have broken posts. However, I would have to sacrifice a port and a time module to make it fully functional as a 41CL. I also run the risk that once opened, I'll find the wrong type of zebra connector.

Would it be better to use one of my HP-41CX's? I know they all have good posts and the correct zebra connector.

Is there any advantage to using a 41CX over a 41CV?

Mark Hardman

      
Re: Which Model HP-41C For the 41CL Transplant?
Message #2 Posted by Ángel Martin on 29 Nov 2011, 11:35 a.m.,
in response to message #1 by Mark Hardman

This is a good struggle to find yourself in, better than not having any suitable donor :-)

Because the TIME module needs to be added to get the timer functional, I'd definitely use a CV over a CX - and if you had more then I'd use the (plain) C - my preferred choice, going from the smallest to the biggest.

In that way you'll still have 7 CX's (fully functional) plus the CL and your "token" C.

Good luck with the transplant!

            
Re: Which Model HP-41C For the 41CL Transplant?
Message #3 Posted by Mark Hardman on 29 Nov 2011, 10:08 p.m.,
in response to message #2 by Ángel Martin

I appreciate your answer. I had to go back and re-read the 41CL manual--and you are correct. Regardless of the model used, a time module is required. So using a 41CX gains me nothing and really would be overkill.

I just received confirmation from Monte that my board is on its way. The donor 41CV has been opened and inspected.

Christmas is coming about a month early at my house!

Mark Hardman

                  
Re: Which Model HP-41C For the 41CL Transplant?
Message #4 Posted by Juergen Keller on 30 Nov 2011, 3:41 p.m.,
in response to message #3 by Mark Hardman

Quote:
Regardless of the model used, a time module is required.
Not true, see Time chip inside 41CL. If you use a CX it's possible to use its timer chip instead of a TIME module.
                        
Re: Which Model HP-41C For the 41CL Transplant?
Message #5 Posted by Ángel Martin on 1 Dec 2011, 10:29 a.m.,
in response to message #4 by Juergen Keller

Technically I guess that's correct but I'm not inclined to get into that kind of intermediate-surgery and very much prefer using a physical TIME module.

Besides, what else do you need the ports on the CL for? :-)

                              
Re: Which Model HP-41C For the 41CL Transplant?
Message #6 Posted by gene wright on 1 Dec 2011, 12:33 p.m.,
in response to message #5 by Ángel Martin

What do you need the ports for?

Printer, Card reader

or

HP IL module

or

Clonix to load new roms into the 41CL

One port is gone with the serial connector if installed.

Might start running out of ports!

;-)

But, I do have a physical TIME module installed in my 41CL which is soon on its way back to me.

      
Re: Which Model HP-41C For the 41CL Transplant?
Message #7 Posted by sylvandb on 29 Nov 2011, 8:18 p.m.,
in response to message #1 by Mark Hardman

Back in 1979-80 with silver prices soaring, many people sold all the silver they could get their hands on. Most of the silver sold was melted down, refined and poured into ingots.

Common (at the time) silver coins were one of the things sold and melted. After all, those common coins had no collector value, but at those silver prices those old coins were worth a lot just for the metal they contained.

Now coin collectors have discovered that what once was common is now rare since so many were melted, and some of what was once rare is considered common since so many were NOT melted.

(http://www.pcgs.com/Articles/Detail/496)

I wonder what HP-41's will be considered common or rare in another 20 years? Will the 41CL cause a significant loss of 41C or CV models leading to a "glut" of the 41CX?

I don't think there is any way to second guess or predict. I find it simply an interesting thought experiment.

            
Re: Which Model HP-41C For the 41CL Transplant?
Message #8 Posted by Monte Dalrymple on 29 Nov 2011, 10:11 p.m.,
in response to message #7 by sylvandb

If you don't attach the 41CL label to the case and keep the
old cpu board (guys, PLEASE don't throw them away), it's easy
to change a CL back to what it started out as.

Actually, the 41CL will always be rare, given that I'm not
really expecting to make a ton of them. That, plus the FPGA
and Flash memory are only guaranteed for 20 years.

                  
Re: Which Model HP-41C For the 41CL Transplant?
Message #9 Posted by Ángel Martin on 2 Dec 2011, 9:21 a.m.,
in response to message #8 by Monte Dalrymple

Quote:
the FPGA and Flash memory are only guaranteed for 20 years.

you mean to say no more CL fun after 70? :-)

Edited: 2 Dec 2011, 9:22 a.m.

                        
Re: Which Model HP-41C For the 41CL Transplant?
Message #10 Posted by Monte Dalrymple on 2 Dec 2011, 12:59 p.m.,
in response to message #9 by Ángel Martin

The 20 years is what the Flash manufacturers guarantee. Since
as far as I know the failure mechanism is charge loss on the
floating gates, reflashing the memory and the fpga should be
sufficient to extend the life. Of course there is no guarantee
that the tools will still exist or work in that timeframe. But
since the design is done in Verilog HDL presumably it could be
moved to whatever technology is common in the future.

Monte

                  
Re: Which Model HP-41C For the 41CL Transplant?
Message #11 Posted by Kerem Kapkin (Silicon Valley, CA) on 2 Dec 2011, 5:30 p.m.,
in response to message #8 by Monte Dalrymple

One of the happiest days in my life, Santa came early! just received my HP-41CL today. Monte, thank you so much for this “Beautiful Functional Art”; it is not only an elegant high technology core for the classic HP-41 but also it is beautiful from both design and manufacturing aspects. So much to explore and learn about the new HP- 41CL functions and capabilities… Will keep me busy for a long time for sure…

Thank you and Best Regards,Kerem

            
Re: Which Model HP-41C For the 41CL Transplant?
Message #12 Posted by Mark Hardman on 29 Nov 2011, 10:18 p.m.,
in response to message #7 by sylvandb

Three paragraphs into your post, I was under the impression that you were suggesting we melt down our surplus HP-41's!

Just as an HP-41CY commands extreme high prices among collectors, I would be certain that a well cared for and operational HP-41CL would sell for a king's ransom.

One thing is certain, I will pass away before I offer any of my collection for sale. So, I've given explicit instructions in my will for the liquidation of my HP calculators.

Mark Hardman

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