2940 Taxonomy; was: Re: SCSI cable needed
jwstephens at msm.umr.edu
Wed Sep 27 07:26:34 CDT 2006
Jeff Walther wrote:
>> Date: Tue, 26 Sep 2006 19:19:55 -0400
>> From: "Roy J. Tellason" <rtellason at verizon.net>
good summary Jeff. I cant see anything you got wrong, but might
clarify that there are two terms in the naming of these boards and
others that need to be mentioned.
the W stands for Wide, or 16 bit, or 68 pin connectors. It is true
that you can have W with SCA type 80 pin connectors as well.
the U stands for Ultra Scsi which is the 40 mb/sec or greater.
Scsi orignally was 5mb/sec. then it was doubled by doing
what was originally called synchronous mode to 10mb / sec.
then ultra 2 came out and went to 80 m / sec. I found a
page that was out in 1988 announcing the Adaptec products
coming which was the AHA-2940U2W which had the
dual channel chips and U2 transfer rate. That is probably
the double 68 pin internal board you are speaking of.
It claimed that the U2W board also supported LVD
The latest transfer rate is Ultra 160. I don't have any
info on those drives.
I think the 80 pin SCA is only a matter of the hot plug
spec and connector, and can be dealt with by adapters
from the 50 pin or 68 pin cables to the SCA back
plane connectors. It also deals with the device address
in the connector.
here is one link to a good page of info.
More information about the cctech