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Two bluescsi?

mloret

Well-known member
Hello. I was wondering if it’s possible to run two bluescsi’ son a Macintosh SE—one from the internal ribbon and the other from the db25? I have an issue where I can get the SE to recognize and run one or the other but not both at the same time. Both units show power but only one HD will show up boot.
 

Juror22

Well-known member
Technically the answer should be yes, but resolution of any issues that you are seeing would largely depend on making sure that both are entirely recognized as separate. (not sure if you have multiple drives set up on each, what addresses, etc), but only one of each address can be out there on the SCSI bus and you need to be sure the termination is correct for the setup. Is the one BlueSCSI basically a clone of the other (other than the db25 connection?) Maybe you could post a bit more of the file configurations you are using?
 

mloret

Well-known member
I have the termination jumpers on both. One drive is HD60 and the other is HD50. Do I need to remove the jumper from the one HD60 since it’s not the last one in the scsi bus?
 

Juror22

Well-known member
I would leave termination turned on the external (db25 attached) one and try turning it off on the inside one. I don't think the assigned numeric value of the SCSI drive/file should matter, since it is not like its a physical location on a cable e.g terminating the last physical device in the chain.
 

mloret

Well-known member
Thank you for the idea, but that didn't work either. With termination off on the internal bluescsi, the computer wouldn't boot all the way. When I turned termination back on we were back to square 1 (only one HD recognized on this bus). I'm out of ideas.
 

Skate323k137

Well-known member
Both need to be terminated. No matter what. The SE has 1 scsi bus and when using both internal and external drives, both ends should be terminated.

I know you have done a lot of this but here is what I would do.

Take a working file and test it on each one. Do not move the SD card over, use 2 separate ones. I have had 2 of the same brand card where only 1 works with BlueSCSI.

Once you have each device, with its own card, able to boot the machine, name the file hd1.hda on one, and hd2.hda on the other. They must be separate scsi IDs because the SCSI bus on the SE does not differentiate internal/external for IDs. The emulator is using this filename to choose the scsi Id for the HDD it is emulating, so I would expect using the same filename/ID on both BlueSCSIs is all but certain to screw things up.

Now, power wise; I have enough concern running one SD device off termination power, so two I could almost certainly see causing problems. I suggested a HD to floppy power cable for your internal one to supplement 5v and hopefully take load off the bus. Did you ever get the polarity of that correct / working?

Have you checked the 5V level while the PSU is under the load of both devices?

Anything in the log file(s) when the failed attempt at using 2 at once happens?
 

mloret

Well-known member
Let me tell you what I just tried:

I kept termination on both.

I've been using different SCSI ID's, however I was using 5 and 6. I did as you suggested, replicated one of the SD cards and set the names to 1 and 2. I confirmed that both images worked.

I connected the floppy power cable to the internal bluescsi.

Same result. Will boot from the internal and only the internal unless I take the SD card out of it, then it'll boot from the db25. If I hold down shift-option-cmd-delete, won't go to db25, still only boots from internal. :🤷:
 

Skate323k137

Well-known member
I connected the floppy power cable to the internal bluescsi.
What does 5V read there?

Also, I'm wondering if the ease of setup is causing an issue, if both drives are QUANTUM FIREBALL with the same identifiers (not scsi ID) it might be an issue. That info should be changeable. I would head for the docs.

Also, log files? Do the process that fails, and then open up both logs. You might just get lucky.
 

mloret

Well-known member
Not sure exactly what you are suggesting to check on the power cable.

i got on the bluescsi discord tonight. Someone suggested downloading scaiprobe which I can mess with tomorrow. I’ll also check the logs again though so far they haven’t told me anything.
 

Skate323k137

Well-known member
Literally just a normal check of 5v. Standard volt meter, one probe on a ground pin, one probe on the 5v of the IDC connector.

I would try reconfiguring one device to have a new hdd name / serial number / etc. I'm not sure how much help Scsiprobe will be here because you'll only be able to run it with the one device attached at a time anyway. Seems like an infinite loop where if you could get the system booted with both drives recognized to use SCSIprobe, you wouldn't need it to begin with.
 

cheesestraws

Well-known member
You should definitely have termination on both, termination should be on both physical ends of the SCSI bus. The Mac, with its two SCSI ports, is just like any other two-port SCSI device.

You should probably be aware that the way that the BlueSCSI drives the bus is extremely dodgy, and treating it as a proper standards-compliant SCSI device is probably a mistake; no guarantee this will ever work.
 

mloret

Well-known member
Literally just a normal check of 5v. Standard volt meter, one probe on a ground pin, one probe on the 5v of the IDC connector.

I would try reconfiguring one device to have a new hdd name / serial number / etc. I'm not sure how much help Scsiprobe will be here because you'll only be able to run it with the one device attached at a time anyway. Seems like an infinite loop where if you could get the system booted with both drives recognized to use SCSIprobe, you wouldn't need it to begin with.
Okay the plot thickens. I got SCSIProbe to run on my Mac SE and sure enough, it does recognize both drives on the SCSI bus and they have the exact same names, just like you said--Quantum Fireball1. Maybe that's the problem, huh? Now I need to figure out how to change that. Any ideas?
 

mloret

Well-known member
Update: I told SCSIProbe to mount volume on startup and boom, they both mounted, two identical images, one for each BlueSCSI! YAY! (POS)
 
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