I have lately found these Everex motherboards and now some questions: 😕

1. What kind of external CMOS battery should I use for them? (Red arrows)
2. What's the crystal oscillator socket? (Magenta arrow)
3. What's the 512K jumper? (Yellow arrow)
4. Any BIOS upgrade for them?
5. Possible to put a faster CPU >33MHz on them?

https://stason.org/TULARC/pc/motherboards/E/E … -GATE-ARRA.html
https://stason.org/TULARC/pc/motherboards/E/E … AY-EV-8038.html