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I have a old PDA board, it is not working, but I want to see the content of memory chip for this board, as far as I know there [might be] some interesting software on it, but the PCB is dead, so I thought, maybe I can re-solder the memory chip to USB compatible board (or any other way) to access the contents.

Is it possible, and maybe someone knows compatible device.

The chip is 63 BGA NAND flash K9F1208R0C-JIBO. Here's the datasheet for it: http://pdf.datasheetarchive.com/indexerfiles/Datasheets-IS86/DSAH00528626.pdf

Nick Alexeev
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user2570174
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3 Answers3

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Since the board is dead and desoldering the device, applying balls and re-soldering to a controller etc. is a fair amount of work ... here is what I'd suggest.

1) leave the component on the board and remove most of the other components.

  • especially the device that interfaced to this flash memory.

2) Solder on leads/wires to the pads from the controller /main interface device

  • that way you can connect the signals without messing with the device itself and potentially damaging it

3) Connect those wires to a small micro-processor of your choice.

  • lead length need not be a concern as you'll be reading this slowly

4) Write some code to fiddle with the bits on the output and allow you to read the bits coming back in.

  • speed need not be a concern.

Chances are someone else has the code out there for you.

Make sure you operate the device at the correct voltage (this may limit your choice of micro-processor)

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Even if you could somehow be lucky enough to remount the NAND Flash chip onto another platform to be able to read out its contents you are likely to find anything of much use on the chip memory.

From the standpoint of programs, they are going to be compiled binary executables that you will make little sense from. Trying to reverse engineer software to discover what it does is a very unproductive procedure. At the same time that activity generally illegal to do considering the context of most program license agreements.

It is possible that some text oriented data may be found on the memory that connects back to a text message in-box or a contact list. If this is not your personal data then it would be generally considered an invasion of the rightful owners privacy for you to posess that data without their permission.

In the long run this exercise is one not worth pursuing.

Michael Karas
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Whilst this would of course be technically possible I see a number of potentially difficult areas that you would need to address:

  1. Desoldering the BGA in a manner that doesn't destroy it;
  2. Finding (or designing) a board which can read the IC;
  3. Resoldering the BGA in a manner that doesn't destroy it;
  4. Interpreting the data you actually get out of it.

For (1) and (3) you could use hot air to desolder, then either reball and put onto a new circuit or very carefully solder tiny wires to the pads. Note that although it's a 63 pin device over half are not connected. If you don't know how to do any of these then it's likely a non-starter.

For (2) as the chip is a standard part by a decent manufacturer it is conceivable that you would find another device that uses the same chip. However this device isn't likely to let you read it easily and might actually trash the contents which would be unhelpful.

Better would be to interface it to a small processor (e.g. an ARM or PIC) and implement the right code to read out the contents. With the excellent datasheet you linked this would be possible but it is still not trivial. See this question for somebody who has done it with a different NAND device.

And even if you get this far then (4) is likely a showstopper. Without details of how the original PDA used the memory you will be left with a bunch of binary data that is almost impossible to interpret.

At the highest level you'll be battling however the PDA divided up the internal pages. Below this will be some form of filesystem which has metadata (information on the names of files, their sizes, locations, flags) and contents (the actual file data). The PDA will probably also use some of this NAND for an operating system and configuration, perhaps in the filesystem but perhaps not.

If it was absolutely critical this could be done, but it would be a long project unless you are already familiar with all four of the areas above.

David
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