Did you specifically download drivers for 8 & 9 (usually HP bundles 8 and 9)? Using System 7 drivers can cause problems sometimes.
Also, the fact that you can't select a hard drive makes me think that it's expecting an HDD on the SCSI bus. The 6100c is pretty old judging by the minimum requirements (68020 Mac), and the software may not know what to do with non-SCSI. I've noticed this with old OCR and backup software for instance.
I have a Scanjet 6300 and it's a friggin' aircraft carrier, but the quality is indeed awesome. It's new enough to where you can use SCSI or USB.
Also, the fact that you can't select a hard drive makes me think that it's expecting an HDD on the SCSI bus. The 6100c is pretty old judging by the minimum requirements (68020 Mac), and the software may not know what to do with non-SCSI. I've noticed this with old OCR and backup software for instance.
I have a Scanjet 6300 and it's a friggin' aircraft carrier, but the quality is indeed awesome. It's new enough to where you can use SCSI or USB.