LC 575 with internal SCSI2SD 5.0 and external ZuluSCSI mini - but not both at once

[Randrye]

Greetings. I was hoping someone here could help me solve a mystery.

I have an LC 575 that's been running happily with a SCSI2SD as its internal drive. I recently got a ZuluSCSI mini I was hoping to use as an external drive.

The ZuluSCSI worked great on my LC 630, but when I connected it to the 575, one of three things would happen:

1) It would boot from the SCSI2SD without detecting/mounting the ZuluSCSI drive images
2) If there were any bootable volumes on the ZuluSCSI, it would boot from there without detecting/mounting the SCSI2SD
3) If there were no bootable volumes on the ZuluSCSI, it would give the flashing question mark, and not boot from the SCSI2SD

I'm not sure what to make of this. It's as if the 575 is treating the SCSI2SD and ZuluSCSI as completely separate SCSI chains which cannot overlap. (Maybe that's why the ZuluSCSI worked on the 630 - it has an IDE internal drive). Maybe has something to do with termination, but I can't think what.

Any insight or suggestions would be greatly appreciated!

 

[fred1212]

Try SCSI probe it will be to do with the scsi id of each device

 

[Randrye]

Thanks fred1212. Fortunately ZuluSCSI lets you swap SCSI IDs with filenames, so it was easy to do some experimenting.

Firstly with no SD card inserted, SCSI Probe just shows the SCSI2SD, the CD drive, and the SCSI controller.

With no hard drive images on the SD card, the computer boots from the SCSI2SD, and an emulated CD drive on SCSI ID 6 is detected with no problems.

With a non-boot HDD image on the SD card, I get this.

Running SCSI Probe from a bootable HDD image shows the SCSI2SD is still being detected...

...and shows up promptly when I click 'mount'.

With the ZuluSCSI Mini, you can sometimes get away with hotswapping the SD card. When I boot from the SCSI2SD, then insert the SD card with non-boot hard drive images on it, SCSI Probe can detect them.

And can then mount them.

So to sum up:

• There are no SCSI ID conflicts.
• On startup with the ZuluSCSI Mini connected but no SD card, it boots from the SCSI2SD.
  • If an SD card with hard drive images on SCSI IDs 4 and 5 is inserted at this point, they can be mounted and accessed.
• On startup, with the SD card in the ZuluSCSI Mini,
  • if there's a non-boot HDD image on SCSI ID 5, I get a blinking question mark.
  • if there's no HDD image on any ID, but an .iso on SCSI ID 6, the computer boots from the SCSI2SD, and the .iso mounts as a CD drive.
  • if there's a bootable HDD image on SCSI ID 5, it boots from the ZuluSCSI Mini. The SCSI2SD can then be mounted and accessed from within the OS.

So the question I'm left with is why an external hard drive stops the computer booting from the internal drive, even though the internal drive is visible to the SCSI controller and mountable from the OS. Is this a termination issue? Is there a way to choose a boot disk on startup?

 

[fred1212]

Have you tried setting Startup Disk in control panel?

 

[Randrye]

Just tried it. No luck. It's like once the ROM detects external hard drives it doesn't bother checking the internal drives.

This is more a nuisance than a problem at this point. With SCSI probe I can get all drives detected and transfer files between them. I'll tinker with this later if I have time, but for now I'm going to leave it.