Bios

Computer Gateway2000 486DX2 60 MHz PhoenixBios

When I start the computer I have on the screen:

Gateway2000
CPU ??? ???Hz
System RAM Passed 00640K
Extended RAM Passed 0015360K

Press to enter SETUP

Cache SRAM passed 0012K
System Bios shadowed
Video Bios shadowed

System battery is dead – Replace and run SETUP
Real time clock error

When I press F2 it says entering setup and reestarts again. BATTERY is new, I changed twice already. What to do to access the Bios? I cleanthe battery socket with a brush and check every pin entrance, the battery looks like a microchip.