SCSI to IDE question - 2 in 1?

[MacTV]

I recently bought a SCSI to IDE adapter.

http://68kmla.org/forums/viewtopic.php?t=2915

I haven't installed it yet - but one thing has me very curious. I've always assumed that it only works with a single drive.

But the (somewhat outdated) manual sort of implies that it has a full fledged IDE controller on board that can access both IDE channel 0 and IDE channel 1.

http://dl.acard.com/manual/english/aec-7720u&uw.pdf (page 4 has the diagram).

So - has anyone ever tried putting a cable on the adapter and trying to put two drives on it? Would the SCSI bus see it as two devices at the same address - or what?

I've also never seen, in the manual, the xlr8yourmac review, or anywhere else, anything about whether the IDE device attached needs to be configured as master or slave, or if it doesn't matter.

I know that if I wanted multiple IDE devices I could just buy another adapter and put it on a different SCSI ID - but if you could get 2 on each adapter that would be sweet.

 

[Anonymous Freak]

Since the adapter only allows one SCSI ID to be set, I would imagine that if it supported multiple IDE drives, it would assign them to different LUNs. (A LUN is a SCSI Logical Unit Number, which is a way of having multiple devices on a single SCSI ID.)

 

[MacTV]

It looks like there needs to be additional hardware to support two drives.

Addonics has an ide-scsi adapter for 1 drive - $85, and 2 drives - $105.

http://www.addonics.com/products/io/ad2idesc.asp

The single drive is about twice what I paid for the Acard.

Unfortunately - or fortunately depending on your point of view, the Addonics one is the LVD 160 SCSI - I have no idea if a regular 68 pin to 50 pin adapter would even work on those.

 

[OtakuMegane]

It looks like there needs to be additional hardware to support two drives.
Addonics has an ide-scsi adapter for 1 drive - $85, and 2 drives - $105.

http://www.addonics.com/products/io/ad2idesc.asp

The single drive is about twice what I paid for the Acard.

Unfortunately - or fortunately depending on your point of view, the Addonics one is the LVD 160 SCSI - I have no idea if a regular 68 pin to 50 pin adapter would even work on those.

It should. These IDE->SCSI adapters are basically a SCSI connector and the chip or two that are missing on an IDE drive, so it functions like a real SCSI drive would.

 

[Charlieman]

The description of the Addonics card suggested by MacTV is very confusing. Is it SCSI II, SCSI III or does it require an LVD interface? LVD, to the best of my knowledge, requires a PCI Mac.

 

[lee4hmz]

The description of the Addonics card suggested by MacTV is very confusing. Is it SCSI II, SCSI III or does it require an LVD interface? LVD, to the best of my knowledge, requires a PCI Mac.

LVD devices, unlike their older "differential" siblings, can automatically fall back to single-ended SCSI if they sense they're connected to an SE bus. They usually have "force SE" jumpers on them as well. About the only extra hardware you'd need is a 68-50 adapter and a terminator (or an old hard drive with a terminator, for that matter) for the cable, since LVD devices don't have terminator packs on them.