Nekochan Net

Hello,

Is there any adapter/converters 68pin to 50pin scsi which works? Almost all of my 50pin scsi hdds died and it's not so easy to find these.
I bought one of this:

Unfortunately it's not working.
Any ideas?

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Which do you want to use? It seems some U320 drives won't work in narrow mode.

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I've opted for SCA drives and adapters like these for 50 or 68 pin applications. But to GL1zdA's point, you should make sure whichever drive you choose will work on a narrow bus. I'd refer to Ian Mapleson's disk drive summary - but you've been around the block before, I doubt you need me to tell you about him.

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Then? ... Now? +MLA ... Other: DEC Sun, DG AViiON, NeXT

When you convert a Wide SCSI bus to a narrow device, half the bus lines end at the converter. So really there should be active termination on this high byte and also forcing the bus to use Single-Ended mode. Otherwise there's a risk of spurious signals confusing the devices attached to the Wide side—disks and the host adapter.

When the converter is terminated properly, it's possible to use Ultra-Wide disks between the host and the converter, and narrow disks after it, at the same time. You do have to arrange the SCSI IDs so that they don't conflict (each narrow SCSI ID shadows two wide SCSI IDs, n and n+8). However, connecting any single-ended devices (wide or narrow) forces the bus to single-ended, with a maximum speed of 40 MB/s for the wide side of the bus.

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He's not going to need to terminate unless the drive doesn't have support to "drop down" to a narrow bus. Since there aren't any active 16-bit devices on the bus the extra lines will be ignored by the (correctly operating) device even if they're floating. I have found that some drives don't autodetect bus width properly (Fujitsu for one), and it needs to be forced 8-bit using jumpers.

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(single-CM)

Thank you for your replies.
I'm using aha2940uw. All hdds are IBM ST(2gb,4gb,9.1gb) they have jumpers to enable narrow mode and termination.
The scsi adapter 68 to 50pin is http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&_trksid=p4340.l2557&item=250999665562&nma=true&rt=nc&si=ggGkB3r4D7ZbNkgY%252FYE%252BJeDtJ%252BI%253D&sspagename=STRK%3AMEWNX%3AIT&orig_cvip=true&rt=nc
Any ideas?

_________________
"Look on wife/girlfriends/parents face when you drag all this stuff(IRIS CRIMSON, ONYX, ONYX2, ORIGIN 2000 ,etc.) home.... Priceless! "
Motorla Series 900(MVME197LE) , Atari TT030, Motorola Powerstack

If you have 68pin drives and an UW adapter, is there a particular reason for using the narrow channel? Why not connect the wide drive to wide port on card? Or do you have some other, narrow devices on the same chain?

I have a 68/50 adapter just like the one you are looking at, which seems to give mixed results but seems OK to connect a wide drive to a narrow host (but not the other way round).

So I have found this does work:
Narrow HBA -> passive -> 68way cable -> drive with narrow-only jumper set : the HBA is not generating / listening to high byte signals, and the jumper turns them off in the drive. I can also use another 68/50 adapter to attach another narrow device to the cable, and that works. This is basically a narrow bus system using a 68 way cable (round rather than ribbon, helps internal airflow). Using a drive without the jumper to force narrow was not successful (but it may have been a dodgy SCSI card, or the drive failing to auto-detect the narrow bus).
Have also used:
narrow HBA (Indigo2 external) -> 50way cable -> external box containing wide drive and passive 68/50 adapter
narrow HBA (I2 internal) -> internally fitted wide drive and passive 68/50 adapter

but this does not (yet) work in a Fuel - hangs when initialising the SCSI card:
U320 adapter (ls1030, IRIX kernel configure for narrow-only) -> passive adapter -> internal 50way ribbon -> external 50way cable -> narrow device (a scanner) [see viewtopic.php?f=10&t=16726273#p7347783 ] I assume the HBA is still generating high byte signals and gets confused, though it did seem OK when connected to an internal, narrow DVDROM using a fully terminated 68 way cable and passive adapter.

good luck!

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