At 01:40 AM 6/7/2002, Alan Priol wrote:
>Can someone explain to me why there are 50 pin, 68 pin and 80 pin SCUSI
>controllers. Is it to do with evolved versions?

This is real simplified, but basically the 50 pin version is the original SCSI 1.
Then, with the advent of SCSI 2 and the far faster movement of data they
required more pins to move data and stepped it up to 68pins, (still the standard
for today).  The eighty (80pin) pin version is unique in that it does not have
a powersupply plug on the drive, the conventional 4 prong plug, rather they
provide the power through the additional 12pins on the drive.

You can buy the 80pin drives and attach a small adaptor to it to convert it
back to the 68pin drive with separate 4prong power connector.  The 80 pin
drive is designed to work with "hot-swappable" hardware, like drive trays.
In a server, a drive server mostly, you will have hot swap drive trays.  Each
tray has a 80pin drive.  Should that drive go bad or you just want to move
it to any array, you can pull the drive tray within a few seconds.   Typically,
80pin drives are considered server drives and 68pin drives are considered
client machine drives.  But, if you can get a great deal on 80pin drives, the
cost of the adaptor, (typically about $15), maybe worth using an 80pin
drive in a client machine.

I know this is highly simplified...  but, I am only trying to explain the basics.

     Bob Wright
The NoSpin Group
http://freepctech.com - http://nospin.org


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