Using UW SCSI hard drives in vintage macs

[pizzigri]

So, I have found a small batch of IBM hard drives that I had purchased back in the day from a folding computer shop. They catered to business clients and had both the low end stuff and high end Server stuff. Anyway, I got maybe 8 of these drives, all of which are 4.5Gb, except one that is 9Gb (and double height).
The drives have what seems to be pretty high end active termination that can be enabled.
these are NOT the infamous Deathstars. These are the Ultrastar drives for Enterprise storage and workstation use, I believe they will NOT die on me like the Deskstars.

the drives are extremely low hours (I made up those hours myself.... so....) and I would like to use them, since I have them, in my vintage macs, that are all 68k based machines.
so here are the questions:
all of these drives are 68pin, UW SCSI drives, 7200rpm SE, and obviously NTFS partitioned.
Do I have a chance to make this work in a, say, LC475, or a Quadra 700? What would I need?

 

[Coloruser]

I am using a 10€ 68pin to 50pin adapter from eBay in my 475 to run a seagate barracuda UW drive. Do yourseld a favor and use one with an extra Molex power socket. I decided to use an external power adapter for the HD as the power consumption was a bit high in an overclocked 475 with lots of ram - had some instabilities when running only off the LC style PSU. Maybe just an issue with the seagate……

 

[Phipli]

Hum. Those adapters mostly lack a terminator and don't work with many if not most hard disks. UW disks frustratingly don't tend to have built in terminators.

 

[pizzigri]

That’s not true, actually most 68pin W and UW SE disks have active termination, it’s the LVD and SCA 80 pin drives that by design do not have termination (being designed for backplane installation with built in very sophisticated termination). I have no experience in interfacing SCSI drives with mismatched interfaces, it has always been a no-no when I worked many many years ago assembling servers as my first job.

this is the drive, I just found the manual online:
https://www.casa.co.nz/computers/Storage/IBM/dchs_ps.pdf

 

[Phipli]

That’s not true, actually most 68pin W and UW SE disks have active termination, it’s the LVD and SCA 80 pin drives that by design do not have termination (being designed for backplane installation with built in very sophisticated termination). I have no experience in interfacing SCSI drives with mismatched interfaces, it has always been a no-no when I worked many many years ago assembling servers as my first job.

this is the drive, I just found the manual online:
https://www.casa.co.nz/computers/Storage/IBM/dchs_ps.pdf

Ah apologies I got them mixed up. Likely because the photos of the adapter above are of an 80pin adapter like the ones I've had trouble with, not a 68pin one.

 

[pizzigri]

Still, I remember very well trying to “see” an external UW drive that was connected with a HD 50 pin to HD 68 pin adapter cable in Windows NT thru a 2906 Adaptec card and it never worked for me.

 

[pizzigri]

Ah apologies I got them mixed up. Likely because the photos of the adapter above are of an 80pin adapter like the ones I've had trouble with, not a 68pin one.

Wow, I did not even notice that. I had not enlarged the pics!

 

[Phipli]

Wow, I did not even notice that. I had not enlarged the pics!

it threw me, my original post is /technically/ correct that 'those' adapters are a annoying. But still not actually relevant to your particular hard disk.

 

[MrFahrenheit]

Here’s a post I made 3 years ago regarding large disks like these:

SCSI drive not recognised

I have this 4,25 GB SCSI drive I wanted to try in a SE/30, but for some reason it's not being recognised. I took it from a Performa 6400, where it works. This is its current jumper settings, I just wonder if I need to change them around somehow?

68kmla.org

Scroll down to post #10

If you’re using them only on a 68040 Mac, you can do one 10MB hidden partition (which holds the driver), one 1.9GB partition (to boot from) and remainder as one large partition. 68040 Macs support SCSI Manager 4.3 which supports volumes >2GB. I’d recommend FWB version 4.5.2.

I would not recommend using any Apple “hacked” tool that recognizes third party drives.

 

[Coloruser]

Ah apologies I got them mixed up. Likely because the photos of the adapter above are of an 80pin adapter like the ones I've had trouble with, not a 68pin one.

Sorry for the confusion. The photos are generic. Cannot access my 475 right now to make a photo of the drive with the adapter.

 

[pizzigri]

Here’s a post I made 3 years ago regarding large disks like these:

SCSI drive not recognised

I have this 4,25 GB SCSI drive I wanted to try in a SE/30, but for some reason it's not being recognised. I took it from a Performa 6400, where it works. This is its current jumper settings, I just wonder if I need to change them around somehow?

68kmla.org

Scroll down to post #10

If you’re using them only on a 68040 Mac, you can do one 10MB hidden partition (which holds the driver), one 1.9GB partition (to boot from) and remainder as one large partition. 68040 Macs support SCSI Manager 4.3 which supports volumes >2GB. I’d recommend FWB version 4.5.2.

I would not recommend using any Apple “hacked” tool that recognizes third party drives.

Wow. That’s actually great! Can you suggest a good vendor of these adapter boards? Maybe a link?

 

[MrFahrenheit]

Wow. That’s actually great! Can you suggest a good vendor of these adapter boards? Maybe a link?

All of my experience is with SCA80 drives.