I own a PRS-650 international version and would like to read Japanese public domain e-books on it. I know you can install custom fonts and make the e-books refer to those, but then I'd still don't have ruby support (furigana) and vertical text display.
Therefore I was interested in the possibilities of switching versions and wondered whether it would be possible to do so by updating the device with the Japanese firmware, rather than the international.
I've already look at a similar thread
in which the opposite was attempted, but found no solution there (instead a discouragement of the applied method).
To investigate, I did the following:
I downloaded both the firmware update tools from the English and the Japanese Sony support site.
While running the tools, I managed to update my PRS-650 with the English package, but the Japanese tool didn't recognize my model. I tried tricking it by changing the USBSTOR entries in the registry, to no avail.
After one attempt I couldn't use the English tool anymore because the firmware was already updated. To see if I might be able to work around this problem, I extracted the installer tools (just a zip file) and I seem to be able to trick the update tool by incrementing the version specs in the "\eBookUpdater\assets\updaterAssets\PRSVersion.dat " file.
This means I might still be able to make an attempt.
I also compared the contents of both the Japanese and English update tools and it turns out that the functional files (dll's) seem pretty much the same, except for the following:
Lastly of course the updater package files are different, as well as the interface files for the update tool itself.
Therefore I thought of the following method and was wondering if anybody has any idea if it might work (rather than bricking my device):
1) increase the version specs in the PRSVersion.dat, so I can have another go.
2) replace the English update package with the Japanese one and rename it.
3) run the update tool to trick it into flashing the renamed "J-PRS-650 Updater.package" onto my device
To me it seems that in order for this to work theoretically, the hardware specs for both the Japanese and International version should be the same. Furthermore, the updater package file should contain all the files needed by the device to operate (rather then external fonts, code libraries, etc).
Can anybody help my shed some light on this and let me know whether I am insane to even consider this?? I don't know about the legality of it either.
Thanks in advance for any support I can get! Any other method to achieve my goal is of course highly appreciated as well!