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Quadra 650 - but no luck with BlueSCSI

VMSZealot

Well-known member
I have a Quadra 650, with internal CD drive, that will happily boot from a SCSI hard disk, Zip drive, CD - it's a happy Mac. It's fast for a 68k too. But it won't boot from BlueSCSI. If I put a BlueSCSI in there then it just sits, all day, with a grey screen - only the mouse pointer visible. I did manage to get it to crash once on startup with the BlueSCSI, before fiddling with the images on the card, with 0000000F / 00000020. But if I put the hard drive back in the machine, it's happy once again.

Okay. So it's a dead BlueSCSI (not an impossibility given the quality of my soldering!)? But no. Because the same BlueSCSI boots my LCIIIs (both of them) and my LC475 fine. I'm perplexed. It's a revision 1.0 BlueSCSI with a 16GB SanDisk SD card. Any ideas, anyone?
 

cheesestraws

Well-known member
BlueSCSI has what I think is some marginal timings on some 040s. Heard multiple reports of unreliability, although the only time I used one it was fine. Best to chalk it up to BlueSCSI shonkiness, I suspect.
 

androda

Well-known member
Sitting on grey screen with no other life signs sounds like a termination issue to me. Also given that this particular unit works on other machines.

Is this one of Eric's V1 designs? If the termpower line in the SCSI cable is low, it will not provide enough voltage for termination to function. Check the termination voltage at the diodes.

If you have a molex to berg adapter, try using that to provide additional power. In some cases, the 5v line in the hard drive power connector is just fine but termpower has sagged to 4.5 volts (not enough to work).
 

robin-fo

Well-known member
My bluescsi runs well with my Q700.. Termination (-power) issues also sound plausible to me. AND are you sure there is no image assigned to SCSI ID 3 on your bluescsi 😉?
 

VMSZealot

Well-known member
I gave that a crack - but no dice. Even with the adaptor, I get the same result. As to the assignments, the images are assigned to 0, 1, 2 & 4.
 

androda

Well-known member
If you have a multimeter, check the voltages on either side of both diodes. This will tell us whether the terminator is getting enough voltage.
 

soundworks

Well-known member
I have BlueSCSI running on my Quadra's.

It worked with the Q840av straight away. However, the Q650 gave me trouble at first. In my case it was a combination of SCSI ID conflict with the CD-ROM Drive and setting termination properly.
 
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