Ability to save pictures as RAW (Y3 Mini game stick)

Hi!

I have Data Frog Y3 mini game stick.
Full data from SD card can be found here - https://disk.yandex.ru/d/Ro5pheZ8heWJwg

There are a lot of familiar *.asd files stored on SD disk.

I used your tool to unpack them. Archives with names like Refcenk004.asd contain files BigYYYY.raw and SmallYYYY.raw.
SmallYYYY.raw is a little preview picture (listed in game stick UI) for particular game, BigYYYY.raw is a big picture with game logo.

I used IrfanView to open these *.raw files. And I was able to open them with following settings: 16 bpp (2 bytes per pixel, RGB 5:6:5), no file header.
BigYYYY.raw is 256x256 pixels, and SmallYYYY.raw is 124x124.

So, we can unpack *asd and open *.raw. The last step is to save my own pictures in exactly the same raw format.

I don't know how to do it. IrfanView can't save raw in 16 bpp. Google didn't help much.