2940UW SCSI CD boot needs FDC enabled \ VOGONS

2940UW SCSI CD boot needs FDC enabled

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First post, by auron

Posted on 2025-10-21, 13:43

auron Offline

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putting this out as a quick reminder, because i ran into this problem and could not find a clearly written solution anywhere. the problem was that the 98se CD was being detected as bootable, but wouldn't actually boot, and no amount of changing SCSI/IDE, drive letter boot order would do anything.

in the end, the issue was that the floppy controller was turned off - the FDC needs to be on as well as an A: drive set in BIOS in order for this to work, at least with this adaptec controller. it's due to it using an emulated floppy, which can be a bit counterintuitive because it's not used when booting the same disc from an IDE drive.

Reply 1 of 4, by 956229

Posted on 2025-10-25, 16:19

956229 Offline

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right

Reply 2 of 4, by auron

Posted on 2025-10-26, 17:18

auron Offline

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a small correction: booting the 98se disc from IDE does in fact use an A: drive as well, though as stated it works without the FDC enabled. maybe this is due to better integration compared to the adaptec SCSI BIOS.

another hint is that with the adaptec card, if an A: drive isn't set in BIOS the drive list upon boot will actually overwrite the HDD listing with a "0 MB" volume. i wonder a biosless SCSI card in conjunction with the internal symbios SCSI ROM would behave differently, though don't have such a card to test that (assuming it does support CD booting to begin with).

Reply 3 of 4, by 956229

Posted on 2025-10-28, 14:22

956229 Offline

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auron wrote on 2025-10-26, 17:18:

a small correction: booting the 98se disc from IDE does in fact use an A: drive as well, though as stated it works without the FDC enabled. maybe this is due to better integration compared to the adaptec SCSI BIOS.

another hint is that with the adaptec card, if an A: drive isn't set in BIOS the drive list upon boot will actually overwrite the HDD listing with a "0 MB" volume. i wonder a biosless SCSI card in conjunction with the internal symbios SCSI ROM would behave differently, though don't have such a card to test that (assuming it does support CD booting to begin with).

没有意义，我发现compaq的 symbios的卡在华硕上无法用，在 h310主板上，win10系统却可以用

Reply 4 of 4, by 956229

Posted on 2025-10-28, 14:26

956229 Offline

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a biosless SCSI card in conjunction (COMPAQ) ON ASUS P3B-Fwith the internal symbios SCSI ROM ,can't find any driver at boot

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