Adding SCSI drive to A4000

[X-ray]

I can help with some of the questions:

1) That 9gb won't be scsi.device, it will be gvpscsi.device.
2) To change the ID of the HD, you will need to use the jumpers on the drive. But if I was you, I wouldn't change anything yet: I would just see if the drive when connected to the GVP SCSI is recognised (have you installed the software for the card yet?) By the way, the HD doesn't have to be any specific ID, such as 6, it must just be a unique ID on that SCSI chain.
3) If there is a conflict between the ID of the HD and the ID of the GVP host controller, it will be easier to change the ID of the card because the jumper pins are clearly marked 'ID' on the card (I think they are J3, J4, and J5).
4) Don't worry about mountlists, just see if the drive can be recognised in HDToolBox. If it can, and you can partition it and quickformat it, you will have the drive available, no further tinkering needed.    

[X-ray]

When you click on gvpscsi.device and then click 'ok' (make sure "wide SCSI board" is NOT checked) does it not look like it is scnning any IDs or LUNs? I mean does the screen with the "Interface, Adr, LUN, Drive, and Size not show any entries at all?

It doesn't sound like a conflict between the board and the drive (but you can put a single jumper on one of the ID jumper pin pairs on the card, just to change it for giggles-sake). Otherwise you need to start asking whether the cables and power are properly connected, and also you will need proper termination because that card doesn't have autosensing termination. So if you have a SCSI ribbon with three connectors, the first one could be attached to the GVP card, the second one (the middle one) will be attached to the drive, and you must find a terminator and put that on the last connector, the third one. 50 pin SCSI ribbon cables are usually 'keyed' so you can't plug them in the wrong way around on devices, but make sure anyway that the stripe on your cable is towards the power connector on the HD.

Tell us if the jumper change and the cable/power check and termination help you or not.

[X-ray]

@ Abou

The reason why I suggested ribbon terminators instead of drive terminators is because I too have old SCSI drives that I can't get jumpers for, or specs (there are two here whose jumpers are unknown to me).
You might get those instead. Something like this:

http://www.stsi.com/Merchant2/merchant.mv?page=STSI_4/PROD/SCSITerminators50/22175