What are these cryptic files?

[Elaine]

OK, techies - what are the following files for? I'll refrain from guessing, even though I have a few guesses.

ramlist.dat
recinfo.log
settings.dat
sstore.hds
stdbdata.dat
stbddata.idx
stdbstr.dat
stbstr.idx
ststore.hds
version.sdk

I don't even know what some of the extensions mean.

The main reason I ask is the player created the following on the microSD card:

ramlist.dat
stdbdata.dat
stdbdata.idx
stdbstr.dat
stdbstr.idx

I take it the other files aren't necessary for the microSD card?

[CrowdAds]

[advcomp2019]

Those look like database and firmware files which are OK files to have.