Re: Dell 670 workstation - SCSI cards

wrote:
> Can an additional PCI SCSI card be installed in the 670, in addition
> to the integrated U320 SCSI buss, to run external scanner, etc?
> I read somewhere in the docs that only the integrated SCSI can
> function at one time. The box has two U320 SCSI HDs.
>
> -Ed
>
I don't know what would be so different about the 670 that it would not
accept a SCSI card. The best advice I can give is to get yourself an
Adaptec 2940 or 2940U and try it. You probably do not want a 2940W or
other adapter with a wide 68-pin external connector, which would only
complicate matters. 2940 and 2940U adapters are very inexpensive now,
so you would not be throwing away big bucks.

With the newer LVD SCSI hard disks, an older single-ended SCSI card is
necessary for a SCSI scanner, SCSI multi-function flash card reader, and
older SCSI tape drives. AFAIK, one cannot mix LVD and SE on the same
(newer) SCSI channel. LVD and SE are two different and incompatible
electronic signals... Ben Myers

Hi!

> AFAIK, one cannot mix LVD and SE on the same (newer)
> SCSI channel. LVD and SE are two different and
> incompatible electronic signals... Ben Myers

It's HVD and SE that won't mix. LVD is "backward" or "downward"
compatible to single-ended SCSI, although some SCSI LVD devices need
to be jumpered to "force" them into SE mode. Some are smart enough to
determine what they are attached to automatically.

William (has a nice set of 15K RPM Fujitsu LVD SCA hard disks in a PS/
2 Server 95a with an SE F/W controller--all fast, all wide, all the
time. :-) )

wrote:
> On Tue, 09 Dec 2008 09:56:56 -0500, Ben Myers <> brought the following
> to our attention:
>
>> wrote:
>>> Can an additional PCI SCSI card be installed in the 670, in addition
>>> to the integrated U320 SCSI buss, to run external scanner, etc?
>>> I read somewhere in the docs that only the integrated SCSI can
>>> function at one time. The box has two U320 SCSI HDs.
>>>
>>> -Ed
>>>
>> I don't know what would be so different about the 670 that it would not
>> accept a SCSI card. The best advice I can give is to get yourself an
>> Adaptec 2940 or 2940U and try it. You probably do not want a 2940W or
>> other adapter with a wide 68-pin external connector, which would only
>> complicate matters. 2940 and 2940U adapters are very inexpensive now,
>> so you would not be throwing away big bucks.
>
> I have an Adaptec high-density (connector) SCSI card in the existing 610
> Wkstn, which the 670 is replacing, that can come out and get popped into
> a PCI slot. It's a BIOS-less adapter card whose model number I cannot
> recall, but it looks like an AIC-7850 in device manager.
>
> -Ed
>
>> With the newer LVD SCSI hard disks, an older single-ended SCSI card is
>> necessary for a SCSI scanner, SCSI multi-function flash card reader, and
>> older SCSI tape drives. AFAIK, one cannot mix LVD and SE on the same
>> (newer) SCSI channel. LVD and SE are two different and incompatible
>> electronic signals... Ben Myers
>
Without a BIOS, the card is something like an Adaptec 2910, 2920, 2930
or similar. The low 2900's from Adaptec were almost all basic SCSI
cards without BIOS, hence unable to support booting from a hard disk or
CD-ROM.

You must already have the external cable with high-density connector on
one end and whatever (50-pin?) connects to the scanner on the other end.
If you are running Vista on the 670, be prepared for the possibility
that the scanner won't work, and do not look to HP for software support.
Well, not completely. I have had some success using scanner software
for a newer HP SCSI (must be SCSI!) scanner with an older ScanJet, but,
then, my success is limited to Windows 2000 and XP. Vista, as we all
keep hearing, is a horse of another color. Maybe it's not even a horse
at all, but a donkey.

Because the SCSI scanner manufacturers have all be capricious (I'm being
nice here) in supporting their equipment with newer versions of Windows,
you might also look at 3rd party SCSI scanner software, for a price...
Ben Myers

Hi!

> Well.. the two 15k Cheetah will be on the mainboard
> SCSI channel, whose cable is more like a bundle of
> twisted pairs, not a legacy ribbon.

That's how IBM did theirs in my machine, although they wrapped the 68-
strand cable with black sheathing to keep any "accidents" from taking
place. (The PSU can swing out and will "guillotine" any cable in the
way.)

I should have thought of this--if you were to attach an SE device to
the LVD connector in your system, it would probably force the whole
bus into SE mode. That could result in some performance loss, because--
if memory serves--single ended SCSI doesn't communicate as rapidly as
differential.

> Just need to pop in a SCSI card out the back with
> a high density connector to plug the HP ScanJet.

I think the original idea of an expansion card with the right port
will do what you want, and it should work fine. This is especially
likely if the add-on card is a "dumb" card (like the one you have)
with no boot-BIOS.

The AIC-7850 that you have should be a fine choice. An AIC-7850 is an
all in one SCSI controller chip that Adaptec intended to be used on
motherboards. It still shows up on some expansion cards.

I also suspect a regular SCSI card like the AHA-2940 would work fine
as long as you disabled its boot-BIOS.

There exist "blank" expansion slot brackets that connect to internal
SCSI cables, but I think they may violate the specifications.

William