Help .....Adaptec 2940UW SCSI problem.

[Trev]

There are quite a few revisions of the 2940UW, but they mainly fall into two major categories--the 2940UW and the 2940UW PRO.

On the 2940UW PRO, you can use any combination of connectors.

On the 2940UW, you can only use two connectors at a time:

1) 68-pin internal, 50-pin internal
2) 68-pin internal, 68-pin external
3) 50-pin internal, 68-pin external

You must set the SCSI controller's termination based on how you're using the connectors. [Searching Adaptec's web site. . . .] Check the AHA-2940Ultra Wide Installation Guide (p.4) for more information.

Trev

EDIT: Always ask for pre-sales engineering support when contacting a vendor. You'll end up talking to a techie who couldn't case less about his employer's support policies and price structure.

[Trev]

If you're running Windows 95/98/Me, you need to partition the drive using FDISK.

If you're running Windows NT/2000/XP/2003, you should be able to see the drive in Disk Administrator (Windows NT) or Disk Management (Windows NT/2000/XP/2003).

If all else fails (i.e. you've verfied that the SCSI bus is properly terminated, the host adapter recognizes the drive, and the Windows disk tools don't recognize the drive), you could try low-level formatting the drive. This is rarely necessary, but if the drive was used on a different host adapter or operated for an extended period of time in a different physical orientation (i.e. horizontal versus vertical), it might help.

Trev

[Trev]

I'm not sure what you mean by "ghosted"--to which process or property sheet are you referring? Device Manager lets you change SCSI communication options for some devices (scanners, printers, CD-ROM drives, etc.), but otherwise, it's just for show.

Does FDISK recognize the drive?

EDIT: Are you sure the drive is single-ended? It could be differential (HVD), which is the "other" SCSI bus signaling method, mostly intended for reliability and long cable runs. However, low-voltage differential (LVD--Ultra2, Ultra320, etc.) should work fine on a single-ended bus. Given that the drive was sold by Compaq, it's probably not HVD if was intended for use in a ProLiant server.

Trev

[Trev]

If FDISK doesn't recognize the drive, then the SCSI controller isn't telling the computer's BIOS about the drive. Windows can still see the drive by enumerating the devices on the SCSI bus, which is probably why it's showing up in Device Manager. Are you positive that the SCSI controller's BIOS is enabled (i.e. the BIOS hook--not the ROM setup utility)? If you're booting from the SCSI controller, then the BIOS is almost certainly enabled.

A good, quick way to rule out Windows would be booting directly to DOS, preferrably with MS-DOS 6.22, but Windows 98 SE DOS should do in a pinch. Try creating an emergency repair disk and booting from that. You can copy fdisk.exe to the disk if it isn't there already.

You can also try fiddling with the performance and compatiblity settings by disabling 32-bit disk access. (I think this is done from the System applet--I'm a bit rusty with respect to Windows 98.)

Also, are you sure the drives don't require a jumper change to work on a single-ended bus?

Trev

[Trev]

After pressing CTRL+A to enter the host adapter's setup utility, you should see an option to "Enable SCSI BIOS" or something similar. This should be set to Yes. During the boot process, you should see a flag that says something like "SCSI BIOS installed" or "SCSI BIOS not installed."

As for the 50-pin side working . . . well, it depends. Different host adapters do different things. Some adapaters only support booting from ID 0, some ID 6. In the case of the 2940UW, you can specify the boot device, and it shouldn't matter which bus (narrow or wide) it's on. (OK, that was a bit off-topic.) Termination or ID conflicts are usually the cause of this kind of problem.

Many drives have two sets of jumper blocks--make sure you're using the right one. Also make sure that SCAM is disabled in the setup utility and that each device has had its SCSI ID set manually.

Trev

[Trev]

The acronym "BIOS" is used to mean lots of different (and confusing) things. In this case, we have four separate entities at work:

1. PC BIOS
2. PC Setup Utility
3. Host Adapter BIOS
4. Host Adapter Setup Utility

The setup utility is usually stored in ROM, EEPROM, or flash memory and is often confused with the actual BIOS. The setup utility is used to get and set values that are referenced by the BIOS.

(This next part is pretty basic, so please forgive me if you don't need this stuff.)

The PC BIOS is what FDISK uses to locate disks. It issues specific interrupts and service calls to find the disks, get their capacities, etc. The host adapter's BIOS can hook into the PC BIOS and provide information about its disks whenever that information is requested from the PC BIOS.

Once Windows boots, however, the 32-bit host adapter device driver kicks in, and the host adapter is accessed directly. (FYI, host adapter = SCSI adapter.)

Trev

[Trev]

Don't give up! You may eventually end up tossing the card, but in the meantime, you'll learn quite a bit about SCSI and PC hardware in general. :-)

Even if you're not seeing the "press + to enter SCSISelect" banner, you can still press CTRL+A when the AHA-2940UW banner appears. If you're not seeing the banner at all, then try the troubleshooting steps that follow.

Is the card in a busmaster capable PCI slot? Is busmastering enabled on the PCI slot? Your motherboard's manual should provide instructions for how to verify busmastering settings.

Have you tried the card in a different system?

Does your motherboard have an extra onboard SATA, IDE, or RAID controller? If so, try disabling it. It should be OK to leave the IDE controllers managed by the chipset enabled, but it wouldn't hurt to disable them just for testing.

Have you removed all other cards from your system? (Although, it's a probably a good idea to leave the video card in. :-))

Have you tried moving the card to a different slot (kind of goes hand-in-hand with verifying busmastering capabilities and troublshooting card incompatibilities)?

Trev

[Trev]

@hikermike

Your motherboard probably lacked an option to boot from either an add-in card or the onboard controller if both were installed. That would be strange, though, as that feature's been available for quite some time (my Intel Zappa motherboard from 1994 could do it).

Trev