Wifi GM MDI Tech 3 Serial Number, How to change?

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We now have 2 wifi gm mdi tech 3s in the shop, along with a couple of genuine ones.. I have added wireless cards to both of the clones now, and they work great.. Problem is that they have the same serial number.. this really is a problem, especially when using wireless.. The MDI manager or sps or GDS2, or tech2win really gets screwed up even if your connected wired and another one shows up wireless on the same network..

Now I have been researching this, and trying to find a solution..

… so bear with me, if your not interested, just stop reading.. lol..

the MDI interface has a hardcoded serial number somewhere inside it.. When you ‘restore’ an MDI, or maybe even just update one(not sure on this yet) the MDI software reads the serial number from the MDI and builds the software for that MDI and then installs it..

You can change the serial number by changing some info on the SD card, but if you have to restore it then it will change back to the original serial number that it had.. You can change it again by editing the file though so all is not lost.. I do not have any other software versions running at the moment so I do not know if this information is stored in the same place every time..

the SD card contents are stored in some sort of a linux format.. Anyone with linux should be able to read the files on the card easily.. I don’t and have no clue how to run linux so I have had a large hurdle..

The registry.dat file contains all the changes for Serial number,wired networking settings, and wireless network settings.. It is encrypted somehow.. I do not know the format, nor do I have any idea how to break it down.. All I can do is use a hex editor and I can see that it is not in plain text/ascii format..

The format of this file changes with ANY change so the changes that I will discuss are from an MDI that has just been restored, you can also click on the ‘clear network settings’ in the mdi manager and return this file to the same format.. If you don’t do this, you will lose countless hours chasing a ghost.. don’t ask me how I know… lol..

Now read slowly and take notes, I may not be explaining this too well.. sorta jumbled..
The serial number is located starting in the line 012844e0 using a hex editor.. Preceding the serial number is “B3 29 30 7D 09 A3 8C 2A 4C 28 62 9F”

After the serial number is “E7 6B 76 E4 1B 4D 06 C3”

there are other locations in the file with these numbers, look at the file location I described, this is where it makes a difference.. That location is with the entire SD card being read with a hex editor.. If you can read the file then look at the end of registry.dat file..

The serial number is 16 pairs of hex numbers..
Anyone with a clone probably has “4E 2E 4D 95 AA 5D F3 F1 C7 3C 44 B9 97 55 A4 19” which somehow translates to 22129579..

It seems that the first 8 and the second 8 are able to be changed with other serial numbers.. But you cannot change from 1st half to 2nd half, or vice versa..
it seems that there is some sort of checksum, if it’s a bad serial number it either crashes if the error is right in the beginning, or errors out to 220 or 221 for a serial number if the first half is ok..

4E 2E 4D 95 AA 5D F3 F1 C7 3C 44 B9 97 55 A4 19 = 22129579
4E 2E 4D 95 AA 5D F3 F1 D3 6D 67 A2 72 17 0F 1E = 22111023

First half is the same, second set is borrowed from another MDI with a different serial number..

I can verify this shows up as a different serial number with the MDI manager and tech2win and sps.. Have had 2 MDI clones working wirelessly on the same network with no obvious errors..

If anyone has any idea on de-crypting these serial numbers/hex numbers, let me know..