2940 Taxonomy; was: Re: SCSI cable needed

Jeff Walther wrote: 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 plane connectors. It also deals with the device address in the connector. here is one link to a good page of info. http://www.transintl.com/technotes/scsi.htm