Getting Commodore "insert WB disk" animation after attachng Jaz drive

[Thomas]

Boot priorities only matter if there is more than one bootable device. The disk animation indicates that there is not even one bootable device.

I still suppose it is a hardware problem. Connecting the JAZ disables the HDD.

Does the JAZ drive have a power supply? If not, maybe there is not enough power for all the JAZ, the HDD and the Amiga from just the Amiga's power supply.

[Thomas]

You should boot from floppy with both drives attached and use Phase5's UnitControl program to check whether the JAZ drive is recognised. The program can also rescan the SCSI bus. Until now you only said that the HDD is not recognised, there is no information about the JAZ drive yet. Maybe the YAZ drive is faulty and the whole SCSI chain is disabled because of some malfunction.

It might be dangerous but it might be a possible test to boot without the JAZ drive and connect it later (or have it connected but power it up later), then use UnitControl to get it recognised.

Could it be that it's not the JAZ drive, but the HDD? Maybe you changed some options on the HDD after you disconnected the JAZ drive last time "in the past".

[Thomas]

The Amiga boots fine with nothing attached, so it can't be the HD (yet).

By "nothing" you mean nothing external, right? The Amiga cannot boot well without the HD attached :-)

There are several SCSI options which can be set in the HD's Rigid Disk Block, like Synchronous, Reselection and so on. Some of them influence the whole SCSI chain. If one of the other drives does not work with one of these options, it might be the reason for the failure.

Where is the Phase5 program you describe? I don't recall seeing it on my HD.

"SCSI Systemdisk" on this page: http://phase5.a1k.org/

invoking the Early Startup screen displays df0:, and the three partitions of a second internal HD, none of which are bootable

Didn't see this before. Is that second internal HD on the P5 SCSI bus, too?

Are you sure that the boot HD has a different SCSI ID than the JAZ drive? Have you checked it?

Are you sure that the internal SCSI config hasn't changed since you used the JAZ drive last time?

IIRC the P5 SCSI kit has the internal devices on one end and the external ones on the other end with the controller in the middle, forming one long SCSI chain. If the termination of the internal devices changed, it might be a reason why adding an external device causes the whole chain to fail.