@Valentinka I can answer you: Jetbook Color is a re-branded definitely Hanvon WISEreader C920 and it has an 800MHz CPU:
http://www.hanvon.com/en/products/eb...ucts-C920.html
and here is a JBC disassembled: you can see what it is:
https://www.mobileread.com/forums/sho...d.php?t=172098