Hi everyone!
So a while back I got myself an old IBM PC with a 486DX4 100MHz and 16mb RAM. A few days ago I got an idea to make it my main PC for DOS and Windows 3.1. I want to use it with an ES1688f sound card and EtherLink III network card but I ran into a few problems.

Problem number 1
It has a century date correction card (MBBisa FERNLINK 2000), and I don't know what to do with it. Becouse of it it's always showing errors of bad CMOS battery and I have to input correct date everytime I unplug power (I changed the battery when I started working with the computer).

Problem number 2
When I plug the power, computer starts automatically even tho it's an AT system. No matter what state the power button is, computer always starts, and when i turn it off with a button it start again after ~1 minute. Like it wants to always be powered on. I don't know what can I do, becouse AT should power on only when the button is in correct state.

Problem number 3
Sound card that I'm using I was never able to get it working under DOS, always becouse of conflicting resources. Only under Windows 98 becouse I was able to change used IRQ. But with this computer I have problems with DMA, which never happend to me. In BIOS there is options to disable chosen resources, for example I can disable DMA 1 which I am using, but it's still not working. I tried with SET=BLASTER and with ESS drivers from VOGONSDRIVERS, but again no change. Maybe it's something with jumpers on the sound card, but I can't find any manual for my version of the sound card, which I can't even find photos of. I want to use this one, becouse the only other sound card I have is Crystal CX4235-XQ3, which I heard don't have really good midi support, which I might try in the future.

Problem number 4
When I tried to play DOOM, game crashes after ~3 minuter and froze the entire computer that I had to turn it off with the power button. Something similar happend when I tried running Day of The Tentacle, but this time game didn't even start and there was only black screen, but I was able to reboot with Ctr+Alt+Delete, not like with DOOM. I don't know if those problems are with the video card, but it's integrated and I don't have any ISA or VESA Local Bus graphics cards, so I would have to buy one, but they're very expensive in my country.

If you could help me solving my problems, it would be very greatfull becouse for now it's the best option for me to have a DOS pc for games, and I don't want to use emulation. And sorry for my bad english