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Will quad memory module HP 82170A keep data when removed from the HP 41C?
If so, for how long?

You can measure the length of time in, wait for it: SECONDS!

:-)

Try it!

(04-16-2016 09:23 PM)Geoff Quickfall Wrote: [ -> ]You can measure the length of time in, wait for it: SECONDS!

:-)

Try it!

If I only had it...

What you need is the HP-41 MEM-O-PAK which was a module wallet with battery backup.

I think I saw a PPC Journal article about how to install a cap in a module to extend pull time to hours.

Might take me a while to find which issue . . .

(04-16-2016 10:53 PM)TASP Wrote: [ -> ]I think I saw a PPC Journal article about how to install a cap in a module to extend pull time to hours.

Might take me a while to find which issue . . .

Thank you, I would be interested.
The question regards changing batteriers in 41C with quad memory inserted. If quad module stay in a slot in 41C how much time one has for the battery change to not loose data in quad module, seconds?

(04-16-2016 10:20 PM)Dave Frederickson Wrote: [ -> ]What you need is the HP-41 MEM-O-PAK which was a module wallet with battery backup.

Thank you. For that price one could buy DM41 or DM41L from Swissmicros.
BTW. How long DM41 and DM41L retain memory contents while batteries are pulled out?

(04-17-2016 06:11 AM)wojtek Wrote: [ -> ]

(04-16-2016 10:53 PM)TASP Wrote: [ -> ]I think I saw a PPC Journal article about how to install a cap in a module to extend pull time to hours.

Might take me a while to find which issue . . .

Thank you, I would be interested.
The question regards changing batteriers in 41C with quad memory inserted. If quad module stay in a slot in 41C how much time one has for the battery change to not loose data in quad module, seconds?

No, you have plenty of time if internal capacitors are ok.
Even too much if you are trying to recover from a crash... ;)

(04-16-2016 10:20 PM)Dave Frederickson Wrote: [ -> ]What you need is the HP-41 MEM-O-PAK which was a module wallet with battery backup.

Very special little accessory that I acquire from Gene.
Some pictures: inside, side, PCB & module.

Sylvain

(04-17-2016 01:26 PM)Sylvain Cote Wrote: [ -> ]Very special little accessory that I acquire from Gene.
Sylvain

Very nice!

I am so jealous!

How about fabricating the board and making a kit for the non CL users? I know I would make one.

Geoff

(04-17-2016 06:57 PM)Geoff Quickfall Wrote: [ -> ]How about fabricating the board and making a kit for the man CL users?

Geoff,

I have put the unit on the project table and if I can replicate it without breaking it, I will gladly publish the PCB layout with the components so you can make one.

Sylvain

(04-17-2016 06:57 PM)Geoff Quickfall Wrote: [ -> ]How about fabricating the board and making a kit for the non CL users?

Everybody should have a CL! (and possibly a spare one).

Angel:

:-)

And see below:

Sylvian:

Merci! I think the Clonix module adapter would work perfectly in this application as they can be soldered to a standard bread board with the battery and caps attached and hard wired. That would preclude the need to create a dedicate PCA.

Yes I remember, if you are quick, you can pull a quad from one machine and plug it into a second without losing data. Of course that is how the board that Sylvian has works. And only in seconds.

(04-16-2016 10:53 PM)TASP Wrote: [ -> ]I think I saw a PPC Journal article about how to install a cap in a module to extend pull time to hours.

PPC v6n7 24 cents RAM Mod

Oh thanks!

That is the article.

We have better capacitor technology these days, so with enough capacitance, the modules content might be protected for days instead of hours.

(04-18-2016 01:04 PM)TASP Wrote: [ -> ]Oh thanks!

That is the article.

We have better capacitor technology these days, so with enough capacitance, the modules content might be protected for days instead of hours.

Better technology, maybe, but quality... :-(

In the last year I have repaired the following items, all of them with the same very failure:

- LG LCD TV, 4 years old
- Samsung LCD computer monitor, 3 years old
- Sony Micro stereo system, 7 years old
- Unknown brand DTV receiver, 2 years old

Guess what? Yes, all of them had faulty electrolytic capacitors in the power source section, and all of them were repaired for just some euro cents in spares, while the official repairing services were, either requesting hundreds of euros, or deeming the devices as non-repairable.

Hi all,

This old post may give you some hints on how to proceed with the capacitor.

http://www.hpmuseum.org/cgi-sys/cgiwrap/...ead=207685

Cheers from Canary Islands.

Diego.