SCSI scanner not recognized

Simon J. Rowe <srowe@mose.org.uk> wrote:

> SCSI is a royal pain in the ar*e, my (working) SCSI scanner is
> now in a box in the loft.

Bummer. I've been dealing with SCSI since the late 1980s. It hasn't
usually been a problem for me.

> The mantra of SCSI is 'have you checked the termination?'.

Also, check the ID.

> Does the scanner have built-in termination?

No.

> If so is there a DIP switch for it?

n/a.

> If not have you attached a terminator?

Yes.

> Is it active or passive?

Passive.

> What other devices are connected to the card?

One CD-ROM and one tape drive.

> What device numbers do they use?

The CD-ROM is ID 1 and the tape drive is ID 5. From /proc/scsi/scsi

Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: COMPAQ Model: CRD-254V Rev: 1.06
Type: CD-ROM ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 05 Lun: 00
Vendor: HP Model: HP35470A Rev: T503
Type: Sequential-Access ANSI SCSI revision: 02

> How many cables are attached to the card?

One external to the scanner and one internal to the above
devices. There is another internal connector (68-pin) in
addition to the internal 50-pin connector being used.

> (some card may have three connectors but only two may be used
> at a time).

My understanding is that the Adaptec 19160B is supposed to
support all connectors at once.

> Do you have a mix of 50 and 68 pin devices?

Not yet. But, I'd like to. I have some SCSI hard drives I want
to hook up too. Those would run off the 68-pin connector.

> Are you sure everything has the right termination settings?

I think so, since it worked with a different version OS. But,
I've had cable terminators wiggle off before. The symptom was
bad read/write errors for that. I'll check the internal devices
to make sure only the one at the end of the cable is terminated.

> As you can see the easy solution is to dump the dinosaur and
> get a USB scanner.

I checked the SANE website yesterday to see what the best
supported scanners were. Then I looked at a price comparison
website scanner section, and an on-line computer shopping store.
There was no overlap between the scanners with "complete" SANE
operability status and those I could actually buy.

Thanks....

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Unless otherwise noted, the statements herein reflect my personal
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David W. Hodgins <dwhodgins@nomail.afraid.org> wrote:
> Ok, so the kernel is not detecting it. You can forget about
> installing or configuring modules, until it does.
>
> You haven't said if you've checked termination.

Neither the CDROM nor the tape drive were terminated on the
internal ultra/SE connector on my Adaptec 19160B Ultra160 SCSI
adapter. Both of these units are on the same 50-pin ribbon cable
and have IDC50 connectors. See here for good SCSI connector
pictures: http://www.ramelectronics.net/html/scsi_connecters.html

The SCSI hard drive is terminated on the 68-pin LVD internal
connector. It works fine.

The UMAX Astra 1220S scanner has a termination on one of its two
DB25 SCSI-1 connectors. The scanner connector connects to the
Adaptec 50-pin HD50 external connector.

For some reason the exact same device setup works on my Mandrake
9.0 system with a BusLogic SCSI card.

With bad terminations on the Adaptec's internal 50-pin connector,
then the scanner on the external 50-pin connector isn't
recognized, nor is the hard drive on the internal 68-pin
connector. But, both the CDROM and tape drive on the internal
50-pin connector are recognized, and both of them are functional,
even with the bad termination.

By disconnecting the 50-pin cable from the Adaptec's internal
connector, then the scanner and the hard drive work just fine.
Obviously the CDROM and tape drive don't work.

> The internel cable must be terminated at the end of the cable,
> either by a device that provides termination, or by actual
> terminating resistors.

68-pin cable is terminated. 50-pin internal cable is
unterminated.

> Same with the external cable.

50-pin external cable is terminated via pass through connector on
scanner.

> The controller must also have termination set, when there is
> only one cable connected, but must not have termination set,
> when both internal and external cables are used.

I haven't found any provisions in the SCSI bios firmware for
changing termination of the card.

> Check the switches on your scanner, to ensure it is providing
> termination and is using a different device id, then the tape
> drive, and cdrom.

Scanner is ID 6, tape drive is ID 5, CDROM is ID 1, hard drive is
ID 2.

Scanner had external termination. Hard drive has external
termination. Neither CDROM nor tape drive have jumpers or
switches for terminations, and I don't have a terminator on their
cable.


Right now I have the 68-pin internal cable disconnected. Xsane
sees the scanner. I haven't tested further than that -- I ran
out of time. I'll look at this some more.

Thanks for the help!

--
PLEASE post a SUMMARY of the answer(s) to your question(s)!
Show Windows & Gates to the exit door.
Unless otherwise noted, the statements herein reflect my personal
opinions and not those of any organization with which I may be affiliated.