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41CL reset - Printable Version

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41CL reset - Ours - 05-19-2021 03:25 PM

Hi,

When I picked-up my CL this morning to ease my unit conversion pains with  “SI>“ (Canada is supposed to use metric, but since our powerful neighbour is not most equipment and materials are not metric either) I got the NONEXISTANT message instead of the answer I was expecting. This means that my configuration had been lost. I’m just starting with the CL so I used the preconfigured power user + unit module plugged in one of the free pages. What I don't understand is that the cat 4 still gives me what I had put in XMEMORY a few weeks ago (JNX from the first chapter of Keith Jared’s book) but all the rest was gone like if a “memory lost” happened. Even the time clone is reset to midnight jan 1st. This machine has a broken lower post that I plan to repair, so I’m not totally surprised that it would eventually reset, but I don’t know why x-Memory is still there?

Thank


RE: 41CL reset - rprosperi - 05-19-2021 05:33 PM

I've no idea about the main RAM contents, they may be gone due to power loss (from the bad posts, etc.) but you can most likely easily recover your CL ROM configuration by simply doing

[XEQ] "MMUEN"

Which enables the CL Memory Mgmt Unit.

When a Mem Lost occurs, often the MMU is disabled, but it keeps the ROM configuration stored so it's easy to restore.


RE: 41CL reset - cdmackay - 05-19-2021 07:53 PM

and the MMU can toggle to OFF without a Memory Lost, e.g. when you remove the serial cable (if you have that option).

As Bob says, MMUEN should get things going, if that has happened.


RE: 41CL reset - twoweims - 05-19-2021 09:09 PM

Hmm...
I have a similar issue going on.

I have two CLs. No broken posts, New zebra strips from the calculator store...

On one of them I find the MMU disabled about half the time when I go to use it.
It was working the last time I turned it off. I do not get Memory Lost and Time and Date are correct.

On the other one I always find the MMU enabled (unless I have done something stupid to it.).

This is nothing that I can't live with. I just wanted to add another data point to the conversation.


RE: 41CL reset - rprosperi - 05-19-2021 11:04 PM

(05-19-2021 09:09 PM)twoweims Wrote:  Hmm...
I have a similar issue going on.

I have two CLs. No broken posts, New zebra strips from the calculator store...

On one of them I find the MMU disabled about half the time when I go to use it.
It was working the last time I turned it off. I do not get Memory Lost and Time and Date are correct.

On the other one I always find the MMU enabled (unless I have done something stupid to it.).

This is nothing that I can't live with. I just wanted to add another data point to the conversation.

Do you connect these CL's to your Mac to update them? If so, make sure you have the PC end of the serial cable unplugged before you insert or remove the cable to/from the 41CL, as it can 'short' the contacts inside, which as Callum indicated will reset the MMU and disable it.


RE: 41CL reset - twoweims - 05-19-2021 11:22 PM

It is not happening during the update process. I just turn it on after using it normally the day before. Nothing plugged or unplugged, just turned back on after being off for a while. No "BAT" annunciator so I assume not a power problem.


RE: 41CL reset - rprosperi - 05-20-2021 12:44 AM

(05-19-2021 11:22 PM)twoweims Wrote:  It is not happening during the update process. I just turn it on after using it normally the day before. Nothing plugged or unplugged, just turned back on after being off for a while. No "BAT" annunciator so I assume not a power problem.

Just to be clear, what I mentioned is not related to the update process per se, but rather the simple insertion or removal of the 2.5mm jack of the serial cable.

Assuming it's not that, and if the posts/contacts are all good, I've no idea, best to wait for Monte to see this and advise. It does sound odd though, as the CL is rock solid reliable as long as the machine is mechanically intact with solid contacts.


RE: 41CL reset - Monte Dalrymple - 05-20-2021 02:04 AM

(05-19-2021 03:25 PM)Ours Wrote:  Hi,

When I picked-up my CL this morning to ease my unit conversion pains with  “SI>“ (Canada is supposed to use metric, but since our powerful neighbour is not most equipment and materials are not metric either) I got the NONEXISTANT message instead of the answer I was expecting. This means that my configuration had been lost. I’m just starting with the CL so I used the preconfigured power user + unit module plugged in one of the free pages. What I don't understand is that the cat 4 still gives me what I had put in XMEMORY a few weeks ago (JNX from the first chapter of Keith Jared’s book) but all the rest was gone like if a “memory lost” happened. Even the time clone is reset to midnight jan 1st. This machine has a broken lower post that I plan to repair, so I’m not totally surprised that it would eventually reset, but I don’t know why x-Memory is still there?

Thank

The reset is almost certainly due to a transient power disconnect. This can happen at any of the pressure-sensitive contact points: battery-spring, battery-connector block, connector block-main board, main board-cpu connector or cpu connector-CL board. Most likely is main board-cpu connector but I have seen it happen at every possible location at one time or another.

As far as the preserved x-memory, the latest OS version (which you have) included Hakan Thorngren’s upgrade that does not erase x-memory during initialization.


RE: 41CL reset - Ours - 05-20-2021 03:18 AM

Hi,

This is an exiting fist post on the forum for myself!

So the transient power disconnect modified the calculator’s state and also reset the time clone (which is piggy backed on the board so it also lost power). The x-memory, registers, stack are still there. Once I executed MMUEN, I the modules were working again. Thanks. But I dont know why the cat 0 does not show the fancy menu anymore? Finally, can you tell me where the x-memory is stored for it not to be erased , is it in flash?

Thanks


RE: 41CL reset - Sylvain Cote - 05-20-2021 12:24 PM

Hello Marc-André,

(05-20-2021 03:18 AM)Ours Wrote:  This is an exiting fist post on the forum for myself!
Congratulation, the ice is now broken. Wink

(05-20-2021 03:18 AM)Ours Wrote:  So the transient power disconnect modified the calculator’s state and also reset the time clone (which is piggy backed on the board so it also lost power).
A power glitch can deactivate the MMU and reset the RTC but you need a power lost of some duration to loose the RAM part.

(05-20-2021 03:18 AM)Ours Wrote:  Finally, can you tell me where the x-memory is stored for it not to be erased , is it in flash?
X-Memory is located in RAM, the information is at pages 66 and 67 in Memory Management section of the 41CL User Manual.

Sylvain

edit 1: typo
edit 2: added the power glitch comment


RE: 41CL reset - cdmackay - 05-20-2021 05:15 PM

Just to add to the experiences…

(05-19-2021 11:04 PM)rprosperi Wrote:  Do you connect these CL's to your Mac to update them? If so, make sure you have the PC end of the serial cable unplugged before you insert or remove the cable to/from the 41CL, as it can 'short' the contacts inside, which as Callum indicated will reset the MMU and disable it.

I always make sure to do this, and it still always disables the MMU, every time. Fortunately, that is the only time it happens, for me.


RE: 41CL reset - Sylvain Cote - 05-20-2021 05:41 PM

(05-20-2021 05:15 PM)cdmackay Wrote:  Just to add to the experiences…
(05-19-2021 11:04 PM)rprosperi Wrote:  Do you connect these CL's to your Mac to update them? If so, make sure you have the PC end of the serial cable unplugged before you insert or remove the cable to/from the 41CL, as it can 'short' the contacts inside, which as Callum indicated will reset the MMU and disable it.
I always make sure to do this, and it still always disables the MMU, every time. Fortunately, that is the only time it happens, for me.
Same here, MMU is being disabled every time I plug/unplug the serial connector to/from the 41CL. (all versions in all calculators)