Can't get SCSI to work

[Cyberey66]

I'm setting up a computer with scsi 50 pin cd-rom, and a 68 pin hhd. My card is the initio 2935UW, it has 68 pin internal ultra wide scsi connector, 50 pin external ultrascsi and 50 pin internal ultrascsi. I support's using just 1 connector or any combination of 2. I can't get it to work with 68 pin internal and 50 pin internal.

Here's what the manual says about using 50 and 68 internal, "Host adapter ID is in the middle of the scsi bus" Does that mean, "50pin ID>Host ID>68 pin ID", or "50pin ID<Host ID<68 pin ID?"

so far I tried,
50 pin drive ID - 1; 68pin drive ID - 4; host ID - 2
and
68 pin drive ID - 0; 50pin drive ID - 4; host ID - 2
and
68 pin drive ID - 0; 50 pin drive ID - 4; host ID - 7

Seems like I tried all possible setting, and thing I should double check? I need to get this setup so I can start my linux box.

[surlyjoe]

OK so U have 2 drives and 2 cables 50 and 68pin respectively right? I take it it is a sinle channel controller correct? make sure you turn termination on on both devices and set the controller for ID7, you should be able to set one device above 7 (8-15) and 1 device below (1-6) I cant imagine why you would have to , but thats prolly what they meant. the 68pin cable may require a termination block on the end if the devices dont show up.

[Cyberey66]

The drive are seen when using them one at a time. I don't know how to go about setting the IDs above 7?

[surlyjoe]

what kind / how many drives you have?

[cloasters]

Is the SCSI ID set by the jumpers of a HDD? Or, if it's an SCA drive, by jumpers on the 68 pin to SCA-80 pin adapter? I seem to remember this, but I've not investigated SCSI for a while.

Also, the available SCSI ID's of a 68-pin to SCA Adapter may only be 1 through 4.

[Áedán]

I'm presuming you actually have an IWILL SIDE-2935UW, rather than an Initio 2935UW.

The SIDE-2935UW only has one SCSI bus, so connecting both wide and narrow devices needs a bit more attention paid to it!

Connect your 68pin device as per normal, and ensure that the 68pin cable is terminated at the end. If the device is not LVD it should allow you to terminate the bus on the device. If the device is LVD you'll need a seperate terminator, as I believe the LVD specs don't allow a device to act as a terminator. Set the Hard disk as ID0. As a basic rule, the first SCSI ID should be the boot device.

Connect your 50pin device as per normal, and either terminate the cable or the device. Set the CD-ROM to be ID1.

The SCSI adaptor card is now in the middle of the bus, and should have ID7. In addition, the SCSI adaptor card needs to have the termination set to either AUTO or to HIGH, rather than ON or OFF. This is because the wide SCSI device terminates all 16 lines, but the narrow SCSI device can only terminate the bottom 8 lines, so the SCSI card has to terminate the remaining 8 high lines.

If you're mixing narrow and wide devices, I don't recommend using the high (8-15) IDs, unless you fully understand how they interact with narrow devices. Basically, a narrow device will interpret IDs 8 to 15 as IDs 0 to 7, which can get confusing!

AidanII

[Cyberey66]

Yes I do have the iwill side-2935UW, thanks for all the info. I'll try that now and see how it works, and yes, the drive is LVD. Soon I'll hopefully have my 2nd computer up for playing around with networking and linux.

thanks, Cyberey66

[Áedán]

If the hard disk is LVD, it won't be operating in LVD mode, as you have a narrow device that almost certainly isn't LVD. Instead, it'll swap to single ended (SE - the opposite of LVD), so you will lose some performance, but I can't say how much!

AidanII

[Cyberey66]

I have the drives set to single ended mode. I was looking into lvd controllers, but they are >$100. Well, I think it need a terminator then, there's no option to set the drive for termination. Well until then I'll just have to use my old 50 pin Atlas drive. I'm having troubles with the scsi card and NT anyway and I need to get that settled.

Again thanks for the info, everything is making sense now.

[cloasters]

LVD drives can't be terminated, a Terminator must be used on the end of the 68-pin cable. Most modern Terminators will auto-sense whether they're terminating an LVD or SE chain. A single channel SCSI Host Adapter will definitely take a performance hit when it's running both ancient SCSI Protocol devices(CD-ROM's or Burners) and modern LVD(U2W, 80 Mb/s and U160, 160 Mb/s) HDD's.

The bright spot is that single channel SCSI Host Adapters made expressly for the "old and slow"[even if the drives are brand new] CD drives(I guess that the data transfer ability of CD drives can't be brought up to modern SCSI standards, period) are inexpensive. If $67(with 50 pin and 68 pin cables) for one shipped from Newegg.com is "inexpensive."

C'mon, let's admit it, SCSI ain't cheap!

[Cyberey66]

Originally posted by cloasters
C'mon, let's admit it, SCSI ain't cheap!

That's pretty true, except if you check ebay you can grab old scsi stuff for dirt cheap prices. Still old scsi sucks, it's big, noisy and not really that fast.

Anyway, I just got that card specifically for a cd-burner about a year ago just so I could burn cd's in the backround with no performance hit on my computer. Well my burner died, so I was left with the card and though I'd recycle it in a system I'm building with all my extra parts. And yes, it does kill the LVD drives speed. The most I ever hit was about 12megs/s, almost half what I get from my 5400rpm ide drive.

Anyway, where can I pick up a terminator, and how much to they run for?

[surlyjoe]

any shop will have a terminator, and a lot of cables have them permanantly attatched to the end.