Размер версии FD - 2Mb (FC - 1Mb), поэтому пришлось обновлять через утилиту @bios из под Windows. СПАСИБО !!!
I followed your suggestions: WBFlash returned "bios is current no update needed" and Afuwin opened but crashed if I pressed any key. Also tried to boot from USB using Rufus, Afudos and ROM but it returned Write Protected. Any suggestions gratefully received.