View Full Version : SCSI and the details??

02-04-2001, 03:36 PM
Okay, I'm familiar with most of the basics of SCSI. I'm kindof missing out on the particulars of a few spots though. For example, can someone fill me in on the difference between Narrow, wide, and ultra wide? I know it's 8, 16, and 32 bit (respectively) but what pin connectors are used for each? I've seen a million different cables for SCSI and there can't be that much of a difference. Also, the termination has got me totally confused. Can someone tell me about that?

Paleo Pete
02-05-2001, 07:08 AM
Not sure about the cable pins, and don't have my books available at the moment, but here's what I can remember about SCSI in general.

Small Computer Systems Interface

Originally it was faster than IDE and capable of higher data transfer, modern IDE drives can keep up.

Each device attached to the chain must have a unique numerical ID. If a SCSI drive is used to boot the computer the boot drive must be device 0.

SCSI can use internal and external devices at the same time and different types of devices, hard drives, CD ROMs, tape drives etc.

Terminators must be present at each end of the SCSI chain, early controllers sometimes required a terminator on the controller card itself, most newer ones have one built in. The terminator is basically a transistor that tells the controller this is the end of the line.

Gary Fields SCSI Central ( http://www.scsifaq.org/) is an informative, if light hearted, look at SCSI. Everything you want to know about SCSI is there, with a sense of humor...I like this guy already...

What is SCSI (http://www.uni-mainz.de/~neuffer/scsi/what_is_scsi.html) is a bit more serious, but has good info too.

And of course Charles has some excellent info in the PC Guide's Small Computer Systems Interface (http://www.pcguide.com/ref/hdd/if/scsi/index.htm) section.

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