SCSI external not recognized on Beige G3 with 8.6

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MIKEinMICH Author

Level 1

20 points

SCSI external not recognized on Beige G3 with 8.6

Hi, I decided i wanted to read what was on an old 2GB external HD with SCSI port. I attached to the SCSI port

on my Beige G3 running OS 8.6. After attaching and powering on the external HD, then starting up the G3, i got

no video - at least not a desktop - after powering down and removing the external SCSI and restarting, it booted

into 8.6 normally. Also i notice that, using "C" key, i can't get this machine to boot up from a startup disk such

as DW or my 8.6 OS disk. Peripherals like printer and the mouse/keyboard all respond normally and an active

ethernet internet connection works as usual. I have the SCSI # selection on the external HD set to 5 - so it isn't

conflicting with either of the two internal HDs in the G3 afaik.

I reset PRAM a few times but that didn't seem to make a difference. Just looking for a way to view and backup

what's on this HD and this G3 has a PCI USB card which would give me a way to offload the external contents

to a thumb drive -- but first have to figure out how to get it to recognize an attached external drive. Always worked

fine - a long time ago ; )

Any ideas appreciated!

Thanks,

Mike

G4 Dual Boot 1.25 MDD, TiBookG4, IbookG3, older PMacs, Mac OS 9.2.x, OS 9.2.2. + Tibook-OSX 10.39, Ibook 10.39

Posted on May 7, 2014 8:36 AM

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Answer 1

Jeff

Level 6

12,328 points

May 7, 2014 11:23 PM in response to MIKEinMICH

The beige G3s had a pair of IDE buses and a single SCSI bus, shared by an internal connection and the external DB-25 port. The first generation of beige G3s that shipped with a Zip drive typically had the SCSI version. The internal hard drive and optical drive occupied the (2) IDE buses, because master-slave configuration of dual drives on the same IDE channel wasn't supported. If your G3 has an internal SCSI Zip drive, its default SCSI address is factory-set to 5, which would conflict with the same address set for your external HDD. If this isn't the cause of your problem, are you terminating the external SCSI enclosure's extra port or did you leave the hard drive's TE jumper installed? I always found that the (more-expensive) active terminators were more stable than the passive type, so I used them with all of my SCSI peripherals.

"Also I notice that, using "C" key, I can't get this machine to boot up from a startup disk such as DW or my 8.6 OS disk."

If the original Apple OEM (either Matshita or Sony) ATAPI optical drive has been replaced, it's possible that the third-party substitution doesn't respond to the keyboard "C" command. This can occur with optical drives lacking the Apple ROM programming, but some third-party optical drives are more Mac-compatible, such as Toshiba and Pioneer.

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Answer 2

MIKEinMICH Author

Level 1

20 points

May 9, 2014 8:52 AM in response to Jeff

Thanks Jeff, i appreciate the info. I don't have the internal zip so left the external on "5" and tried again with a different cable just on a whim. It worked with the different cable... i do recall what you mean about the active terminators - this one worked with the passive type -- this time anyway; )... Thanks for the note re "C" drive - indeed i don't have the original OEM HD on this machine so that may well explain why i don't get the "C" command response -- but hopefully i can still select 'startup disk' on the Control Panel settings in the future...

I also happen to have a FW PCI card on this machine - as well as USB PCI card - so perhaps i can fire it up in Target Firewire mode but i suspect it may be too old for that.

Anyway for now i accomplished what i needed -- Thanks again!

Mike

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Answer 3

Jeff

Level 6

12,328 points

May 9, 2014 10:14 AM in response to MIKEinMICH

"It worked with the different cable..."

That can make a big difference. Years ago, I bought a Belkin SCSI cable with a DB-25 connector on one end and a Centronics-50 on the other. It never worked correctly, and I think it was the lack of additional grounds in the cable. The O.D. of the cable jacket was only about 5/16," which probably indicated that they used an outer shield and tied that to some of the ground pins. The better quality cables - which I started buying - had the additional 25 ground conductors, making the cable jacket's O.D. at least 1/2" - if not more. You get what you pay for — not that the Belkin cable was inexpensive.

"...perhaps i can fire it up in Target Firewire mode but i suspect it may be too old for that."

To be the target computer, it needs to have onboard FireWire ports and not an add-on PCI card. You can connect a newer Mac in Target Disk Mode to a beige G3 (host), and then start up the newer computer. Its hard drive should show up on the beige G3's desktop.

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