Onyx Terminator drive box backplane jumpers

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mosiniak
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Joined: Fri Jun 30, 2017 2:51 pm

Onyx Terminator drive box backplane jumpers

Unread postby mosiniak » Sun Dec 10, 2017 2:33 pm

On the drive box backplane there are several jumpers (see photos below). They are divided into two groups (suffix A and suffix B), probably one group to one SCSI channel (A nad B). Channel A is setup to Differential mod and channel B to SE mode.
Do you know what each jumper does?
Attachments
scsi3.jpg
scsi2.jpg
scsi1.jpg
:OnyxR:

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jan-jaap
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Re: Onyx Terminator drive box backplane jumpers

Unread postby jan-jaap » Mon Dec 11, 2017 6:18 am

I don't think the individual jumpers are documented, though the TRMPWR jumpers likely have something to do with the system supplying SCSI termination power.

HERE you can find some info but it basically says what you know already.

To convert a SCSI bus from DIFF to SE mode, you need to:
1. Replace the red daughtercard on the IO4 with the green one
2. Change the jumpers on the drive box backplane
3. Replace the DIFF terminator on the drive box backplane with an SE terminator.
4. Change the jumpers on *all* sleds in the drive box to reflect the new setup.

I have done this in the past; my deskside Challenge L has more modern LVD Cheetah 15K disks (running in SE mode).

Jumpering sleds is documented in the Challenge/Onyx owner's manual.

NB: nice quality photos!
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mosiniak
Posts: 7
Joined: Fri Jun 30, 2017 2:51 pm

Re: Onyx Terminator drive box backplane jumpers

Unread postby mosiniak » Mon Dec 11, 2017 6:51 am

Thank you for reply. Probably the best way is to write down jumper settings for SE or HVD settings.

I took photos of each part of Onyx SCSI box and took photos during assembly/disassembly. When I finish cleaning up this part (SCSI box) I will share these photos. They can be useful for someone.
:OnyxR:

mosiniak
Posts: 7
Joined: Fri Jun 30, 2017 2:51 pm

Re: Onyx Terminator drive box backplane jumpers

Unread postby mosiniak » Wed Dec 20, 2017 1:17 pm

mosiniak wrote:Channel A is setup to Differential mode and channel B to SE mode.

It was wrong, channel A (3 jumpers) is SE and B (6 jumpers) is HVD.
:OnyxR:


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