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50g freezes on SD card access
01-03-2020, 12:02 AM
Post: #1
50g freezes on SD card access
A fellow 50g owner has tried multiple SD cards including one that was only 128 MB in size, in both FAT16 and FAT32 formats, only to find that his 50g locks up when he tries to access any of the SD cards. He confirmed there are no bent pins inside the SD card slot. He then made two videos showing what leads to the freeze as follows:

https://drive.google.com/open?id=1-mnRWe...fZxh2Ax-2E

After the calculator freezes (in the first video), he has to press the reset button on the back.

In the second video he put in the card with the calculator on and tried to open the file manager, but it froze until the card was removed.

I had him re-solder all 12 pins at the back of the SD card slot, but that did not solve the problem.

Someone in a Facebook group suggested I Google the industry standard SD card slot pin-outs and try to find a pin that has its logic state stuck and unchanging using an oscilloscope, but I am unsure what those logic states should be on the 50g. Do you need of you know? And even if my friend was able to determine that the logic state of one pin was unchanging when in fact it should change after an SD card is inserted, what then? I would assume that’s a chip level problem that cannot easily be fixed.

Any thoughts and suggestions would be appreciated. Thank you.
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01-03-2020, 10:47 PM
Post: #2
RE: 50g freezes on SD card access
90 views of my opening post after 1 day but not a single reply. :-(

Maybe the magic words will help...

PRETTY PLEASE?
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01-04-2020, 12:09 AM
Post: #3
RE: 50g freezes on SD card access
(01-03-2020 10:47 PM)JDW Wrote:  90 views of my opening post after 1 day but not a single reply. :-(

Maybe the magic words will help...

PRETTY PLEASE?
1.Does the SD card work in other devices?
2. Many people may still be on vacation and may replay on or after the 1/6/2020...
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01-04-2020, 01:29 AM
Post: #4
RE: 50g freezes on SD card access
(01-03-2020 10:47 PM)JDW Wrote:  90 views of my opening post after 1 day but not a single reply. :-(

Sounds like a pretty good measure of how many people have no idea what the problem might be! Smile

Sorry JDW, perhaps as radwilliams suggests, someone more knowledgeable may respond in good time.

Who decides?
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01-04-2020, 06:34 AM
Post: #5
RE: 50g freezes on SD card access
Hi,

SDcards are known to be able to freeze other devices like cameras, hi-fi systems, pc as well.

When this happens, nothing but a hard reset of the device helps.
The reasons why this freeze occurs varies and stays a bit cloudy.

IMO fat16 format is a "must" with SDcards used in conjuction with an HP50g.
fat32 format is no good at all: at best the access time will be much slower, at worst the whole card will not work.

The capacity of the SDcard must not exceed 2GB.
In my experience SDcards with one GB work in most cases even better.
1 GB are officially supported by the HP 50g; 2GB might work.

The bus speed should be 12.5 or 25 MB/s.

SDcards come in five card families:
the original Standard-Capacity (SDSC, 128MB-2GB, fat16),
the High-Capacity (SDHC, 2GB-32GB, fat32),
the eXtended-Capacity (SDXC, 32GB-2TB, fat32/exFAT),
the Ultra-Capacity (SDUC, 2TB-128TB, exFAT)
N.N.

Only the original Standard-Capacity (SDSC) with <= 2GB will work in an HP 50g.
SDHC, SDXC & SDUC will not do.

Instead of using a microSD with adaptor the old large card format tends to work best.

In my HP 50g a K*n*s*o* 1GB and a S*N*I*K 2GB SCSC work fine.
Both cards are fat16 and in the old large "full size" format (no adaptor).

UHS-I,-II, -III or express will not work (bus speed too high).

In general there is much more going on when a SDcard communicates with a device.

There is no open spec, but at least three cases are known, in which the controller shuts down the SDcard explicitly (has to do so in order to comply with the spec):
1) wrong format (e.g. fat32 with SDSC)
2) some timing error at the beginning of the interaction between card and controller.
3) bus speed too high; no common one

What could be done now ?

* clean contacts in calculator & SDcard with isopropyl alcohol (pharmacy)
* try a SDSC with max 1GB capacity in "full size" from another vendor
* try to find out more about the format of the SDcards that cause the freeze:
fat16 or fat32 alone is not enough. What is the sector size ? Partition type 06h ?
A controller and/or firmware may freeze if confronted with the wrong block size.
* try to borrow a working SDcard from another HP50g-user nearby.
It should work without a flaw.
* delete lost.dir or any other file on the SDcard if you do not need the file anymore.
A corrupt file might also cause a "freeze".

In some cases a corrupted SDcard can be repaired with CHKDSK (win) or Disk Utility (MacOS) or better with the "SD Memory Card Formatter"
But beware: formatting destroys data.

Good luck !
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01-04-2020, 11:03 AM
Post: #6
RE: 50g freezes on SD card access
after a hard reset, trying the PINIT command 3 or 4 times helps...
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01-04-2020, 01:22 PM
Post: #7
RE: 50g freezes on SD card access
(01-04-2020 06:34 AM)tuxfish Wrote:  IMO fat16 format is a "must" with SDcards used in conjuction with an HP50g.
fat32 format is no good at all: at best the access time will be much slower, at worst the whole card will not work.

The capacity of the SDcard must not exceed 2GB.
In my experience SDcards with one GB work in most cases even better.
1 GB are officially supported by the HP 50g; 2GB might work.

The bus speed should be 12.5 or 25 MB/s.
UHS-I,-II, -III or express will not work (bus speed too high).

* delete lost.dir or any other file on the SDcard if you do not need the file anymore.
A corrupt file might also cause a "freeze".

In some cases a corrupted SDcard can be repaired with CHKDSK (win) or Disk Utility (MacOS) or better with the "SD Memory Card Formatter"

Thanks. I don't think bus speed is an issue because he tried an old 128MB card formatted as FAT16 and it still locked up his 50g. Here's exactly what he told me:

I tested with different sd cards. I got some borrowed cards, all of different sizes. I made sure about the file system the cards were using, and in some of them I removed the partition table and created a new partition with the FAT 16 and then FAT 32 file system. One of the cards was only 128MB and was partitioned by me with a FAT 16 file system. All these cards work correctly on my computer. I also tested one of these mobile memory cards and an adapter, and freezes just the same.

Based on the above, it appears the SD card is freshly formatted and doesn't seem like there are any files on his SD card. He seems to be able to use them on a PC just fine, so there's nothing wrong with the card itself.

The only thing that he has not tried is cleaning with alcohol, so I will advise him to do that, but I remain very skeptical that will be a fix here, especially since he did a visual inspection with a magnifying glass and all looked fine to him.

I will also have him try the PINIT command, but will that really fix a freeze like this?

Hmmm....
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01-04-2020, 02:07 PM
Post: #8
RE: 50g freezes on SD card access
What is the ROM version installed?
Try to reinstall the latest ROM version 2.15 https://www.hpcalc.org/details/7097 using '2MB FIX.zip': "This ROM image will completely overwrite the Flash Memory in the 50g and return it to original condition." Plus this version "Fix SD card Fat32 / Fat16 access not exactly following Microsoft specification (build 85) ".
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01-04-2020, 10:51 PM
Post: #9
RE: 50g freezes on SD card access
(01-04-2020 02:07 PM)Simone Cerica Wrote:  Try to reinstall the latest ROM version 2.15 https://www.hpcalc.org/details/7097 using '2MB FIX.zip'

What's the method for performing the update WITHOUT using an SD card (which is obviously needed in this case)?


(01-04-2020 02:07 PM)Simone Cerica Wrote:  Plus this version "Fix SD card Fat32 / Fat16 access not exactly following Microsoft specification (build 85) ".

No link.
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01-04-2020, 11:17 PM
Post: #10
RE: 50g freezes on SD card access
(01-04-2020 10:51 PM)JDW Wrote:  What's the method for performing the update WITHOUT using an SD card (which is obviously needed in this case)?

There is a PDF document in the linked .zip file which explains how to do the update via USB cable (which requires having the Conn4x ConnKit installed).

--Bob Prosperi
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01-05-2020, 11:35 AM
Post: #11
RE: 50g freezes on SD card access
(01-04-2020 10:51 PM)JDW Wrote:  
(01-04-2020 02:07 PM)Simone Cerica Wrote:  Try to reinstall the latest ROM version 2.15 https://www.hpcalc.org/details/7097 using '2MB FIX.zip'

What's the method for performing the update WITHOUT using an SD card (which is obviously needed in this case)?


(01-04-2020 02:07 PM)Simone Cerica Wrote:  Plus this version "Fix SD card Fat32 / Fat16 access not exactly following Microsoft specification (build 85) ".

No link.

As suggested by rprosperi it is possible to update the ROM via usb. You will need the HP 50g, 49g+ and 48gII PC Connectivity Kit & HP USB Drivers. In the hp4950v215/ hp50g ROM Upgrade.pdf it is explained how to do it and all the bugs fixed are listed.
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01-05-2020, 11:03 PM
Post: #12
RE: 50g freezes on SD card access
Have all the cards your friend has tried been formatted on the same computer? If so, try formatting them on another computer (with a different SD card writer).

And note that Macs write various crap to filesystems. Either use a "clean eject" utility, or don't use a Mac to format them.

Cambridge, UK
41CL/DM41X 12/15C/16C DM15/16 71B 17B/BII/bII+ 28S 42S/DM42 48GX 50g 35s 30b/WP34S Prime G2
& Casios, Rockwell 18R :)
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01-06-2020, 07:56 PM
Post: #13
RE: 50g freezes on SD card access
My 2 cents:
* Could be a power issue: fast cards might want to draw too much current. Repeat the test but with the calculator powered from the USB port.
* Repeat the test with newRPL. It uses a completely different SD card driver, much more flexible than the stock ROM. If newRPL can read them, then it's a software issue.

Other than that, there's not much else that can be done, if one of the pins that drives the SD card is fried, you won't be able to communicate. The pins come directly from the CPU so there's nothing you can replace. It would be very unlikely that one of the tiny resistors got damaged, and that's pretty much the only component that exists between the card and the CPU.
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01-08-2020, 08:30 AM
Post: #14
RE: 50g freezes on SD card access
Folks, thank you for all the input. I spoke to my friend and he updated from 2.08 to 2.15 and used a 512MB SD card and said the problem was resolved.

He said he previously (prior to ROM upgrade) tried microSD cards with an Adapter and none of those worked. But he also said that he lives in Brazil and many companies there advertise SD card sizes that are not in fact the size you get.

Lastly, he added that after updating the ROM, his 50g will format the SD card as FAT32. I mention that because someone earlier in this thread said FAT16 is "a must." I would think if that is true, the 50g would use that format. But in fact, it uses FAT32. Hmmm.

Anyway, thanks to all who helped my friend!
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01-08-2020, 10:37 AM
Post: #15
RE: 50g freezes on SD card access
(01-08-2020 08:30 AM)JDW Wrote:  [...]
He said he previously (prior to ROM upgrade) tried microSD cards with an Adapter and none of those worked.
[...]
I guess that these micro-Cards were SDHC, not simple plain old SD.
As it was said above only older SD cards can be used.
As far as I know these are not sold anymore - I got mine from E-Bay and sometimes from surplus show sales.
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01-09-2020, 12:26 AM
Post: #16
RE: 50g freezes on SD card access
(01-08-2020 10:37 AM)Martin Hepperle Wrote:  As it was said above only older SD cards can be used.
As far as I know these are not sold anymore - I got mine from E-Bay and sometimes from surplus show sales.

I seem them sold on Amazon (no mention of them being SDHC at all):
https://www.amazon.com/SanDisk-512MB-Sec...0000AKVJC/
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01-09-2020, 02:23 AM
Post: #17
RE: 50g freezes on SD card access
Quote:tried microSD cards with an Adapter
on my 50G a 2gb full size sd card fine.... once I use an adaptor and a micro card the calc takes around 7s to power on... thought this was usual so imagine my surprise when first using a full size card and instant power on!

never been near the card + adapter route since.

HP-28S (1988 US model)
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01-09-2020, 06:28 PM
Post: #18
RE: 50g freezes on SD card access
(01-09-2020 12:26 AM)JDW Wrote:  I seem them sold on Amazon (no mention of them being SDHC at all):
https://www.amazon.com/SanDisk-512MB-Sec...0000AKVJC/

That Amazon page has 1GB cards for the same price.
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01-10-2020, 08:18 AM
Post: #19
RE: 50g freezes on SD card access
(01-09-2020 02:23 AM)edryer Wrote:  
Quote:tried microSD cards with an Adapter
on my 50G a 2gb full size sd card fine.... once I use an adaptor and a micro card the calc takes around 7s to power on... thought this was usual so imagine my surprise when first using a full size card and instant power on!

never been near the card + adapter route since.

Was the MicroSD card formatted as FAT32 or FAT16?

— Ian Abbott
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01-10-2020, 08:33 AM
Post: #20
RE: 50g freezes on SD card access
(01-10-2020 08:18 AM)ijabbott Wrote:  
(01-09-2020 02:23 AM)edryer Wrote:  on my 50G a 2gb full size sd card fine.... once I use an adaptor and a micro card the calc takes around 7s to power on... thought this was usual so imagine my surprise when first using a full size card and instant power on!

never been near the card + adapter route since.

Was the MicroSD card formatted as FAT32 or FAT16?

edryer needs to answer that question, but like I said before, my friend told me he formatted his SD card inside his 50g and he said it formatted it with FAT32. That contradicts what someone earlier in this thread said about FAT16 being the best. I would think the 50g would format cards in whatever format it considers "best." Which would indicate it thinks FAT32 is best. I've not tested formatting an SD card in my own 50g in a long while so I cannot say anything one way or another right now.
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