Requirements for use of calibration file

**OldTom** · 31st December 2015, 11:34 AM

I have read about half of this entire forum by now, as wel as TomTom's own and Navi Total's, so far without finding an answer.

My Go Classic is still working after 10 years, but it now seems to have digitizer trouble, as the leftmost column of characters can no longer be reached. I played around with the keyboard options large/small and QWERTY/ABCD. No luck.

I have tried the non-invasive operation, removing bits of dirt around the edges. No luck.

I placed a cal.txt file in the root of the SD card with modified settings. I checked the HW settings: the cal.txt is disregarded.

Now I wonder: is there a minimum requirement in bootloader and/or navcore for this calibration file to work? Or is it purely hardware dependent?

**biggerdave** · 31st December 2015, 12:05 PM

Nothing to do with bootloaders, just cal.txt etc. unfortunately it's not a exact science & you need to try a few small changes each time until you get the right set-up specifically for your actual device.

All I can suggest is more reading around here [Only registered and activated users can see links. ]

**OldTom** · 31st December 2015, 02:41 PM

Mmmm, I have been working in IT since the previous millennium (1984, to be precise) and at any time when a config file is to be taken into account on any hardware and operating system, this is done by code. That code can either be an application program or a (embedded) bootstrap program.

On many computers you have a core prog like a BIOS, on the TomTom this seems to be the bootloader.
Such bootstrap programs are known to have parameter files nowadays, you used to have to "burn" them with a separate tool - I'm referring to EEPROMs here.

Given that TomToms runs on a modified Linux operating system, this is called by the bootloader, I guess.
Navcore is in my understanding an application program that is called from Linux.
Or maybe Navcore *is* the modded Linux plus the application program rolled into one?

Maps are just data files that go (or not) with a specific version of the application program.

A calibration file is also just a data file. It will either be called from the bootloader, from the OS or from Navcore. Hence my question what it is that uses the file.

The link you sent is useful though: I see there that Navcore 8.051 and previous used a file called calib.txt instead of cal.txt. Although I have Navcore 9.510 installed, cal.txt is not recognized. I'll have a try with a calib.txt instead.

Cheers!