Hauppauge 4860 mboard question

Hi, don't know whether this is appropriate for this list, but I'll ask anyway (it's over 10 years old). I've got a machine which has a 4860 motherboard, this a combi 80486/80860 with EISA slots. Overall it works fine, but there is a small problem enabling the cache. The battery is broken, so after turning off it loses it's BIOS and EISA configuration. When this happens I can go into the BIOS and setup everything, *enable the cache*, and boot from ide disk. Problem is since the EISA configuration is still invalid, the SCSI controller does not work. After I setup the EISA configuration with the DOS CF.EXE utility, the SCSI controller works, but the cache is disabled, and I cannot re-enable it in the BIOS menu (menu item is disabled). What can the problem be? Anyone experienced s/th similar? regards, chris