scsi detection help

HooD

hey,

my first post, i've tried a search for my problem (although i learnt a lot of other thing i didn't know) i didn't get the exact answer i was looking for.

my system specs first of all...

2500+ barton (oc to 3200+)
asus a7n8x deluxe
1 gig of ram
2x 80gig ide maxtor drives
400 watt psu
radeon 9800 pro

scsi stuff...

adaptec 29160N
Seagate Cheetah 36.7GB (ST336704 LCV)

dont know much about scsi but wanting to learn so found a cheap hard drive and scsi card on ebay to play around with, then i will invest in some better kit once i fully know what im doing with it.

i got it all connected using a 68 pin lvd/se cable and a 68pin to 80pin adapter, my first mistake was the adapter maxed out at 40mb/s, other than that it worked fine and was detected in windows etc.

i recently got an ultra 160 adapter and my scsi card refuses to detect the drive now, im pretty sure i've got it set up correctly with the jumpers etc. The adapter also says its unterminated but i thought the terminator built into the cable would do the same thing?

i've read the adapters are no good and you lose a lot of performace using them is this true?

thanks and sorry for boring you with the long post

Tex

You need good adapters. Cheap ones are more hassle then they are worth. You really should not use either the adapters or mobile racks (which are basically single drive bays the size of a cdrom) with more then 3 devices per scsi channel as the signal seems to degrade down the line. With more then 3 per channel you need a backplane.

I have had enough bad luck with adapters shorting out on the back of drives I always use elec. tape and coat the back side of the adapter when I use them. If you only have a couple drives you might consider mobile racks. I have a bunch of u320 capable single mobile racks that don't cost much more then a GOOD adapter. And are tons more dependable and guaranteed to work up to u320 speeds.

With an adapter or a mobile rack the only settings should be for scsi id. With one drive you want it to be id-0.

use GOOD adaptec or amphenol cables with a u320 terminator on the end. Attach the drive to the NEXT closest connector on the cable to the terminator!

make sure the jumpers on the card are set to provide term power.

I hate adaptec controllers. If you want I can sell you cheap known good/working mobile racks, scsi cables and even LSI controllers/scsi drives if you wanted.

Ones tested and guaranteed to work together. I mean crap you could even send me a drive and I'll set the whole mess up for you and test it for nothing.

If the drive chain was the same (adapters, drives and cables) exactly as before and the drive is not detected now I sorta would blink and look twice at that adaptec controller from ebay. Its one thing to not be detected at the correct speed but another to not be detected at all.

make sure you have term power enabled or set to auto on the controller via jumpers if possible. also check if the 29160 has settings to let the card auto terminate. Both ends of the scsi chain need terminated. Both at the drive and controller. Most controllers auto terminate and can sense when they need to auto terminate their end of the chain. Some controllers pulled from servers etc.. are not jumpered that way as some of the old time scsi guys really still hang terminators on BOTH ends of the chain them selves. Or use a external terminator on a spare internal channel.

Just download the manual and double check all the jumpers.

Link me to the adaptec manual so I don't have to go find it and I'll double check the settings for ya. I have 20+ years setting up scsi drives and controllers.

Tex

HooD

first off thanks a lot for all the info i really appreciate it

when i said i did a search i actually ended up just browsing the boards with a coffee, and how i learnt a few things i didn't know already most of the posts were by you so was kinda hoping you would post to help.

like i said i just got these components to get a better understanding of how to set up scsi and see if its for me, if i find it is i would probably look into investing in something a lot better, so at the moment its just the one drive im looking to connect.

The drive chain was not altered when i switched adapters, so i'll defineatly be looking into the alternatives you mentioned. and i'll probably try it again tomorrow afternoon now i've calmed down a little and took a break from it.

i would of loved to take you up on your offer as well but im from england and can see that postage rocketing.

manual here

thanks again for all the help