seeking SCSI-2 host adapter

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Haines Brown

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Sep 12, 2014, 8:38:39 PM9/12/14
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I have an old DAT drive I'd like to access from a new machine, and so
need a SCSI-2 (2 x 50 pin) host adapter. I have found it difficult to
pin down a suitable card. It should be inexpensive. Any recommendations
or strategies?

Haines Brown

Robert Heller

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Sep 12, 2014, 9:27:12 PM9/12/14
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$9.99 (no bids yet):
http://www.ebay.com/itm/Adaptec-AHA-2940-SCSI-50-pin-PCI-Inteface-Working-interface-pulled-from-PC-/271603118711?pt=US_Computer_Disk_Controllers_RAID_Cards&hash=item3f3cceb277

From:

http://www.ebay.com/sch/?_nkw=Adaptec%202940&clk_rvr_id=694824541849

E-Bay can be your friend...

Note: if this is an *internal* drive, almost all 'wide' AHA-2940 controllers
will have a 50-pin internal header, in addition to the (possibly multiple)
68-pin headers. Even though the AHA-2940 'wide' controller is *meant* for wide
devices (either LVD or SE or both), it can handle narrow devices. In the olden
days, PCs that had wide SCSI-2 disks (LVD or SE), also had a SCSI CD-ROM,
which would always be narrow (50-pin ribbon), so the Adaptec very conviently,
included a 50-pin internal header, just for this eventuallity. This also will
work for an internal narrow SCSI DAT drive -- the controller is not fussy.

*Some* wide AHA-2940 controllers also had a *narrow* external connector as
well (eg to accomodate an external *narrow* device (CD-ROM, CD-Burner, Tape
drive, whatever). Adaptec made a wide range of AHA-2940 cards, with various
combinations of narrow and wide connectors (internal, external, with various
connector formats). Right now, E-Bay has 455 listings for "Adaptec 2940" --
there are probably *several* that will work for you.

>
> Haines Brown
>

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Haines Brown

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Sep 14, 2014, 9:48:47 AM9/14/14
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Robert, I thank you for the helpful tip.

Scott Lurndal

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Sep 15, 2014, 12:12:34 PM9/15/14
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Robert Heller <hel...@deepsoft.com> writes:
>At Fri, 12 Sep 2014 20:38:39 -0400 Haines Brown <hai...@histomat.net> wrote:
>
>>
>> I have an old DAT drive I'd like to access from a new machine, and so
>> need a SCSI-2 (2 x 50 pin) host adapter. I have found it difficult to
>> pin down a suitable card. It should be inexpensive. Any recommendations
>> or strategies?
>
>$9.99 (no bids yet):
>http://www.ebay.com/itm/Adaptec-AHA-2940-SCSI-50-pin-PCI-Inteface-Working-interface-pulled-from-PC-/271603118711?pt=US_Computer_Disk_Controllers_RAID_Cards&hash=item3f3cceb277
>

For which you'll need a computer with a PCI (_NOT_ PCI-Express) bus.

Very few new computers in the last 5 years have had a PCI bus.

Robert Heller

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Sep 15, 2014, 12:58:00 PM9/15/14
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The Wendell Free Library recently bought a *brand new* Dell T20 Server and it
has one PCI slot. Actually all current vintage computers have a PCI *bus*, it
is just a question of whether they have any plain PCI *slots*, which are a
different animal.

Scott Lurndal

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Sep 15, 2014, 1:32:02 PM9/15/14
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Robert Heller <hel...@deepsoft.com> writes:
>At Mon, 15 Sep 2014 16:12:34 GMT sc...@slp53.sl.home (Scott Lurndal) wrote:
>
>>
>> Robert Heller <hel...@deepsoft.com> writes:
>> >At Fri, 12 Sep 2014 20:38:39 -0400 Haines Brown <hai...@histomat.net> wrote:
>> >
>> >>
>> >> I have an old DAT drive I'd like to access from a new machine, and so
>> >> need a SCSI-2 (2 x 50 pin) host adapter. I have found it difficult to
>> >> pin down a suitable card. It should be inexpensive. Any recommendations
>> >> or strategies?
>> >
>> >$9.99 (no bids yet):
>> >http://www.ebay.com/itm/Adaptec-AHA-2940-SCSI-50-pin-PCI-Inteface-Working-interface-pulled-from-PC-/271603118711?pt=US_Computer_Disk_Controllers_RAID_Cards&hash=item3f3cceb277
>> >
>>
>> For which you'll need a computer with a PCI (_NOT_ PCI-Express) bus.
>>
>> Very few new computers in the last 5 years have had a PCI bus.
>
>The Wendell Free Library recently bought a *brand new* Dell T20 Server and it
>has one PCI slot. Actually all current vintage computers have a PCI *bus*, it
>is just a question of whether they have any plain PCI *slots*, which are a
>different animal.

Actually no.

They have one or more PCI-Express controller(s). PCI-Express is a point-to-point
interface using TLP's for data and command transfer. The only thing shared with
PCI is the software enumeration techniques (using the PCI Configuration Space
and PCI-Express Extended Configuration Access Method (ECAM) or linked by the
host bridge into the intel standard CF8/CFC configuration cycle generation
hardware).

Modern intel systems _appear_ to have a PCI bus for software enumeration
of the on-chip devices, but actually don't internally use PCI signalling or
electrical bus structures at all.

Some vendors will include a pci bridge to support legacy cards, but that is
unusual and pretty much limited to Dell server systems.

Haines Brown

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Sep 18, 2014, 8:16:32 AM9/18/14
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Interesting discussion, but it leaves me uncertain. I had in hand an old
EISA bus SCSI adapter, which tells you how out of touch I've been. I've
usually gone on assumption that if a card fits into slot it's the right
card. The AVA-2906 I have in hand fits an expansion slot on my new
motherboard, and so I thought I was all set. But in light of the
discussion, I now wonder.

I'm told that PCI slots have generally been out of fashion for years and
most new motherboards don't have them. However, I have a new Gibabyte
GA-H97-D3H, and it has: two PCI Express x 1 slots, two PCI Express x 16
slots and two PCI slots. These PCI slots seem to accommodate my AVA-2906
SCSI adapter card. How do I reconcile this with the discussion?

Haines

Michael Baeuerle

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Sep 18, 2014, 8:31:30 AM9/18/14
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Haines Brown wrote:
>
> Interesting discussion, but it leaves me uncertain. I had in hand an old
> EISA bus SCSI adapter, which tells you how out of touch I've been. I've
> usually gone on assumption that if a card fits into slot it's the right
> card.

This assumption is in general true for the electrical side of the
problem. If the card fit into the slot, you can assume that both sides
will not be damaged.

> The AVA-2906 I have in hand fits an expansion slot on my new
> motherboard, and so I thought I was all set. But in light of the
> discussion, I now wonder.

The AVA-2906 card seems to have no Boot-capability. But for other cards
that have it, the software in the onboard ROM must match the computer to
work. Therefore that you can plug the card into the slot is not
sufficient for a card to work as expected in some cases.

> I'm told that PCI slots have generally been out of fashion for years and
> most new motherboards don't have them. However, I have a new Gibabyte
> GA-H97-D3H, and it has: two PCI Express x 1 slots, two PCI Express x 16
> slots and two PCI slots. These PCI slots seem to accommodate my AVA-2906
> SCSI adapter card. How do I reconcile this with the discussion?

According to the Adaptec homepage:
http://www.adaptec.com/en-us/support/scsi/2900/ava-2906/
the AVA-2906 is a 32 bit, 5V-only PCI card. Therefore it should have a
single notch in the PCI connector at the back side (opposite direction
to the external SCSI connector).

If the slot provides the wrong voltage, the notch of the card don't
match the slot and you can't plug in the card. Wikipedia has a nice
overview picture of the 4 PCI slot types:
https://upload.wikimedia.org/wikipedia/commons/thumb/1/15/PCI_Keying.svg/400px-PCI_Keying.svg.png

Robert Heller

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Sep 18, 2014, 9:03:00 AM9/18/14
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It sounds like the EISA and PCI slots use the same edge connector. I have no
clue as to whether the EISA card will actually work correctly in a PCI slot.
Question: does the card fit the slot when the motherboard it installed in a
case? It is my understanding the the ISA card edge is on the 'other side' of
the card from the PCI card edge. I wonder if the EISA is also on the ISA
side, since EISA is supposed to be downward compatible with ISA.

Here is a comparison of buses (with pictures showing cards 'side by side'):

http://philipstorr.id.au/pcbook/showtell/show6.htm

Although PCI Express is the 'current thing', it appears that (dispite rumors
that the plain PCI is a dead horse), 'plain' PCI slots are still appearing on
many current vintage motherboards.

Michael Baeuerle

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Sep 18, 2014, 10:00:51 AM9/18/14
to
Robert Heller wrote:
>
> It sounds like the EISA and PCI slots use the same edge connector.

No, they have nothing in common. Because the components are not on the
same side of the board, even the position of the slot on the mainboard
don't match the mounting screw in the case.

> I have no
> clue as to whether the EISA card will actually work correctly in a PCI slot.

EISA is an extension of ISA and therefore ISA cards will fit (and can be
used) in EISA slots. But not PCI cards.

Maybe there is confusion with 64 bit PCI slots that are also longer then
the more common 32 bit PCI slots (but are usable for 32 bit PCI cards
too).

Robert Heller

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Sep 18, 2014, 10:55:14 AM9/18/14
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At Thu, 18 Sep 2014 08:03:00 -0500 Robert Heller <hel...@deepsoft.com> wrote:

>
> At Thu, 18 Sep 2014 08:16:32 -0400 Haines Brown <hai...@histomat.net> wrote:
>
> >
> > Interesting discussion, but it leaves me uncertain. I had in hand an old
> > EISA bus SCSI adapter, which tells you how out of touch I've been. I've
> > usually gone on assumption that if a card fits into slot it's the right
> > card. The AVA-2906 I have in hand fits an expansion slot on my new
> > motherboard, and so I thought I was all set. But in light of the
> > discussion, I now wonder.
> >
> > I'm told that PCI slots have generally been out of fashion for years and
> > most new motherboards don't have them. However, I have a new Gibabyte
> > GA-H97-D3H, and it has: two PCI Express x 1 slots, two PCI Express x 16
> > slots and two PCI slots. These PCI slots seem to accommodate my AVA-2906
> > SCSI adapter card. How do I reconcile this with the discussion?
> >
> > Haines
>

Actually the AVA-2906 is NOT an EISA card and is in fact a PCI card, which is
why it fits in a PCI slot. An EISA card would not fit in a PCI slot.

Haines Brown

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Sep 19, 2014, 7:07:16 AM9/19/14
to
Michael Baeuerle <michael....@stz-e.de> writes:

> Haines Brown wrote:

>> The AVA-2906 I have in hand fits an expansion slot on my new
>> motherboard, and so I thought I was all set. But in light of the
>> discussion, I now wonder.
>
> The AVA-2906 card seems to have no Boot-capability. But for other
> cards that have it, the software in the onboard ROM must match the
> computer to work. Therefore that you can plug the card into the slot
> is not sufficient for a card to work as expected in some cases.

Thank you for the information. I'm just using the card to run an old DAT
drive and so no need to boot with it.

Haines

Haines Brown

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Sep 19, 2014, 7:24:14 AM9/19/14
to
Robert Heller <hel...@deepsoft.com> writes:

> At Thu, 18 Sep 2014 08:03:00 -0500 Robert Heller <hel...@deepsoft.com> wrote:
>
>>
>> At Thu, 18 Sep 2014 08:16:32 -0400 Haines Brown <hai...@histomat.net> wrote:

>> > I'm told that PCI slots have generally been out of fashion for
>> > years and most new motherboards don't have them. However, I have a
>> > new Gibabyte GA-H97-D3H, and it has: two PCI Express x 1 slots, two
>> > PCI Express x 16 slots and two PCI slots. These PCI slots seem to
>> > accommodate my AVA-2906 SCSI adapter card. How do I reconcile this
>> > with the discussion?

> Actually the AVA-2906 is NOT an EISA card and is in fact a PCI card,
> which is why it fits in a PCI slot. An EISA card would not fit in a
> PCI slot.

Sorry I gave that impression. The EISA card edge connector differs
greatly from the PCI connector. For example, contacts are split in two
to double the number for a slot.

>> Although PCI Express is the 'current thing', it appears that (dispite
>> rumors that the plain PCI is a dead horse), 'plain' PCI slots are
>> still appearing on many current vintage motherboards.

This is why I raised the question, for my Gigabyte GA-H97-D3H is hardly
"vintage" and I find many other current boards have PCI slots. The PCIe
seems more than just the current thing, but offers a performance
advantage. I had therefore assumed that that card manufacturers would
shift to PCIe and drop PCI, which is why I found it rather surprising to
see so many motherboards and cards still using PCI.

Haines

Robert Heller

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Sep 19, 2014, 8:13:03 AM9/19/14
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I expect that there are lots of existing, supported cards that are PCI and
where replacing those card with PCIe is not cost effective (either there isn't
a large enough market for a PCIe version or there is no speed advantage). And
including 1 or 2 PCI adds little to the cost of the motherboard. *I* don't
think that PCI slots are really going to completely vanish anytime soon,
except for very low-end (low-cost) motherboard/desktop systems.

>
> Haines

David Lesher

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Oct 3, 2014, 6:21:11 PM10/3/14
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Haines Brown <hai...@histomat.net> writes:


>I'm told that PCI slots have generally been out of fashion for years and
>most new motherboards don't have them. However, I have a new Gibabyte
>GA-H97-D3H, and it has: two PCI Express x 1 slots, two PCI Express x 16
>slots and two PCI slots. These PCI slots seem to accommodate my AVA-2906
>SCSI adapter card. How do I reconcile this with the discussion?

Well, PCI != PCIE
They threw in 2 legacy slots to be nice guys.


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