SCSI Hard Disks by Dan Crumpler For several months, many of you have become keenly interested in SCSI (pronounced like "scuzzy") hard drives. After setting up three of them I would like to share some of my experiences with you. Please understand that I am not a technician, electronics wizard, engineer, or anything else except a "computer nut" as stated in a recent newspaper interview. I don't understand the inner workings of how the SCSI does what it does, but I do know that it does work very well. In newer high speed computers, SCSI drives are common. Most PCs never needed the speed of SCSI before, simply because they didn't have the computing power that you can commonly find in the new 386 and 386SX machines. A 386 computer needs the speed of a fast drive like you can find in a SCSI drive, and you don't have to take out a second mortgage to pay for it. One of our local stores is selling an 85 Meg Seagate SCSI for just $550.00, which is quite a bargain. Besides being relatively cheap (excuse me-inexpensive), SCSI also allows you to daisy-chain up to seven devices onto one singe card, called a host adaptor. Imagine plugging in your tape-backup, hard disks, scanner, disk drives, CD-ROM, and so forth into just ONE card? Suddenly, those three expansion slots on the new PS/2 and other compact computers look better and better. While I personally haven't used multiple devices on the one card yet, I am grateful that it is possible. The cost of Seagate's ST02 host adaptor for its line of SCSI drives is only $45.00, and that includes a floppy disk controller built-in. This is especially important on the old IBM-PCs that only had five expansion slots to begin with, all of which will probably be filled already. What are the disadvantages? The only one that I have found is that some of the ST02 adaptors do not support 1:1 interleave like they are supposed to. My friends in the business feel that this is a temporary setback, and will possibly be corrected with a new upgrade chip. There are other host adaptor cards out now that do support 1:1 interleave and an incredible transfer rate, but they cost far more than $45.00. Would I buy another SCSI drive? I can't think of any reason not to, except that the new ANSI SCSI-2 standard will soon be out that supports both 16- and 32-bit buses, as well as the current 8-bit buses. The performance on SCSI-2 should be dazzling, but if you need a hard disk now, the current SCSI drives should be quite adequate for all but the fastest computers. They come in all sizes all the way up to more than 1,000M bytes. When you consider how many of these monster hard disks could be linked together on one computer host adaptor card, SCSI does indeed offer tremendous storage potential. [Reprinted with permission from the Manatee PC Users Group newsletter] (Bradenton, Florida).