I booted with a 98SE startup floppy and ran FORMAT on the logical drive in the extended partition. It saw the full capacity.
Then I tried another test. I used FDISK to delete that logical drive and extended partition then rebooted. Now
FDSISK is only seeing this 40 gig drive as a 32 gig, claiming the primary partition that occupies 50% of the drive is using 62%. Didn't change BIOS settings. Let me go and manually select Large instead of LBA... WTH? It self-altered the detected capacity down to 32 gig?! That's another trick I've never seen, a BIOS altering on its own the drive settings its own auto detect entered. Suspiciously weird that it would cut it to 32 gig, a limit that was supposed to have been fixed in one of the early updates.
Redid the auto detect and it detects it as 40 gig. Going to FDISK etc again. OK, it is *finally* formatting the correct 19+ gig capacity for half the drive. Perhaps because the part of the MBR etc for the primary partition was *not* written by FDISK? I have Win95 all setup and updated so I'm not eager to completely wipe it and start all over just to verify that 98SE FORMAT and 98B's scandisk have some problem with this hard drive and this board and BIOS when 98SE FDISK or Partition Magic (and who knows which other format utilities) are used.
I'd very much appreciate this BIOS getting a fix because it does seem to have some kind of oddities.
If at some future time I need to replace the hard drive, I might 're-discover' its quirks. Or if the BIOS decides again that the drive should be 32 gig, that could do bad things to data on the 2nd partition.