A3000: How to disable on-board SCSI?

Hi all,

I know I haven't posted for a bit, but I do read the threads and lurk a bit on here still :ninja:

Anyway, I have what might seem like an odd question to you: can I disable the on-board SCSI controller on the A3000D.

My last remaining SCSI drive has died :( but I do have a Buddha IDE card so have stuck an IDE drive in it. It works well, but I have a delay upon startup whilst the machine checks what drives are on the SCSI interface. This gives about a 30sec-1min delay each time I restart (mostly upon cold reboot, but sometimes on warm reboot)

I've checked all the documented jumpers but still unable to find anything that does what I want.

Thanks in advance guys (and gals)

Cheers
woody.cool

As a last resort, what about pulling the WD SCSI chip out? I don't know if that'd work, but it's a possibility.

Yeah, I'm tempted to do that. I hope it won't come to that though.
Does removing the SCSI chip stop anything else working?

What about putting a cable on the SCSI and terminating it right away?

Or just termination right on the header?

That's what I thought! Is there such a device as a SCSI terminator that can be directly plugged in to the header on the motherboard?

I doubt that'll work. A SCSI "Terminator" is a completely different beast to an IDE "Terminator"

With SCSI, the terminator is an essential part of the operation of a SCSI subsystem. Essentially, it provides enough resistance to make the cable appear infinitely long, so that you get no reflections on the bus. If there are no devices on the bus, termination won't really buy you anything. They're called "Terminators" because they terminate the end of the cable.

The A4000 IDE terminator is a completely different beast. It's designed to deactivate the IDE bus. As far as I can tell, they were invented purely for Kickstart 3.1 Amigas. These are called "Terminators" because they terminate the IDE interface entirely. I'm not aware that a SCSI equivalent exists. If you Google for SCSI terminators, you'll likely only get hits for the first type.

Quote:

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Originally Posted by woodycool

Yeah, I'm tempted to do that. I hope it won't come to that though.
Does removing the SCSI chip stop anything else working?

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If you remove the SCSI chip, you will have a green screen and the A3000 won't boot.

Quote:

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Originally Posted by LTAC

Quote:

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Originally Posted by woodycool

Yeah, I'm tempted to do that. I hope it won't come to that though.
Does removing the SCSI chip stop anything else working?

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If you remove the SCSI chip, you will have a green screen and the A3000 won't boot.

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Thanks LTAC, I won't try it then.

Anybody got any other ideas?

1. Kickstart with SCSI support removed?
2. Editing the configuration NVRAM so that no SCSI ID is scanned for device presence?
(I'm fully unaware if that's possible and what tools might be needed, just an idea drawn from how things are on bootable PC SCSI controllers).
3.Plugging something into the external SCSI connector just to keep the controller satisfied (e.g. an el-cheapo external SCSI CD ROM)?

Do you have scsi terminating resistors installed on your motherboard?