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SCSI Ultra 3 for older Mac

OtakuMegane

Well-known member
Yes. SCSI drives are normally designed to be backwards compatible with all the older standards. I have never encountered one that wouldn't work with an adapter.

 

maceffects

Well-known member
Great I will post once I get it to confirm it works, because a new 36gb hard drive for only $25 is awesome, I can't find a 80mb used one from the early 90s for that!!

 

Bunsen

Admin-Witchfinder-General
Yes. SCSI drives are normally designed to be backwards compatible with all the older standards. I have never encountered one that wouldn't work with an adapter.
No, just no. Ultra160 drives are usually back compatible; many Ultra320 drives are not. You need to check the manufacturer's data sheet for that drive and confirm that it can be set to a backwards compatible mode, SE or Single Ended, IIRC. And you need the right adapter.

But then, a simple USE THE SEARCH would have shown both of you that this has been discussed here before at great length.

Or, you know, Google.

*facepalm*

 

maceffects

Well-known member
Well I'll test it once it comes. Good old google had conflicting info. If it works I'll buy some extras. Will post soon guys. I have 3 diffent kind of adaptors

 

coius

Well-known member
Bunsen, so you know, my Ultra 320 74GB SCSI Drives use an adapter to go to 68-pin from 80-pin SCA. The adapter has a jumper you can set it into SE as well as TE options. I don't know of any Ultra 160 SCA-80 drives out there, do you?

I might be wrong, however I do know my ultra320 hitachi drives do indeed do SE. I have tested it with a Power Mac 7200 and they worked. So there is a way to at least set SCA-80. Maybe it depends on the adapter. I haven't found any Ultra-320 68-pin drives out there. It seems the 320 were meant for SCA systems.

 

Trash80toHP_Mini

NIGHT STALKER
I haven't counted the pins yet, but all mycards are Fast SCSI II on a 50 pin internal or the narrower of the two external connectors.

Is the wider of the two connectors on SCSI III drives the SCA connector?

I have two narrow SCSI II adapters to 50 pin internal SCSI Cabling, one with active termination and one with no termination as far as I can tell.

Has anyone got a good source for the fast & wide SCSI III connector -> 50 pin internal DIP Cables and the narrow SCSI II internal pigtails inside my StudioArray Boxen?

____________________________________________________________________________________________________________________

I usually do my own searching, but an explanation from a verbal thinker would be a big help, as would links.

I've already started a thread that's attempting to collect all the related links and our institutional knowledge of this subject in one place, this thread will be posted there as well.

Ultra320 SCSI for Macs? Other Server interfaces? ;)

 

Trash80toHP_Mini

NIGHT STALKER
I haven't checked for lowest prices or searched anything out about quality of connectors.

Active vs. Passive Termination or the "no termination on the adapter at all" options have not been researched as yet.

SCSI Adapter Links and Images of ConnectorTypes

It looks like what I'll be needing is this SCA 80F to 50M SCSI Adapter to cable the new SCA Ultra160 drives up internally to the IDC 50 header connectors for internal chains on my ATTO Silicon Express II and PLI QUICKSCSI V.I.D. Cards.

I haven't figured out what to do about the two Radius Studio Array Boxen yet. They're set up for HD68 Wide SCSI. Apparently that's what connector would be on the the Backside of the FWB JackHammer Card that shipped with the Studio Array . . .

. . . the fast/wide bus FWB JackHammer has successfully eluded my grasp up to this point. :-/

 

Trash80toHP_Mini

NIGHT STALKER
I've started the search for the all the threads related to the SCA/server drive on older Macs.

There are a couple more links listed in the catch-all thread linked above. However it's early and my brain wigged out already . . .

80 pin -> 50 pin SCSI adapter in SE/30

Do the Ultra 160 and (when voluntarily complient) the Ultra 320 Drives step down into Fast SCSI 2 mode when using these adapters on a Fast SCSI 2 Controller? My working assumption would be that they do, as the spec. for Ultra 3 160 required backward compatibility, but confirmation would be nice!

 

maceffects

Well-known member
UPDATE:

The computer doesn't see the drive, I used another SCA drive on this adapter before but maybe it needs adjustments to the jumpers, not sure? The other SCA is only a 4gb.... I'm lost but it may not be as easy guys :(

 

Bunsen

Admin-Witchfinder-General
maybe it needs adjustments to the jumpers
Did you find the drive manufacturer's support page? You quite likely need to set jumpers on the drive, as well as/instead of the adapter. The drive needs to be set in Single Ended mode - if it can.

68pin and NOT 80
More likely to work - but it's not the pin count that matters, it's the SCSI mode/s the drive is compatible with.

This time, try checking the manufacturer's page first ;)

 

maceffects

Well-known member
Just set the jumpers on the orignal drive to "Force SE" so I think thats force single ended. Maybe that will work. What about PARITY?

This drive is LVD/SE (so should be able to be single ended)

 

maceffects

Well-known member
Well I added the jumper but the computers still didnt see it in force Single Ended mode. The SCA to 50pin works with a SCA 2gb drive from 96 as is, but the jumpers on it aren't marked :(

Not sure what to do. I need a 9gb+ drive.

 
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