Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!sli!news From: rdh@sli.com (Robert D. Houk) Newsgroups: comp.periphs.scsi Subject: Wren-V Parity jumper Message-ID: Date: 12 Aug 90 19:06:01 GMT Sender: news@sli.com (news) Reply-To: rdh@sli.com (or uunet!sli!rdh) Distribution: comp Organization: Software Leverage, Inc. Arlington, Ma Lines: 22 As I was replacing one of our Wren-V disks yesterday, going through the jumpers, I was reminded of a puzzle: What is the purpose of the Parity Jumper? All of the disks come with the jumper removed, and the manual is delightfully terse on what it actually does. I assume installing the jumper enables parity checking? On disk Data? SCSI Data? Time of Day? If Parity is not enabled (no jumper), does the disk use ECC (standard features include "48 bit ECC polynomial" Error correction). Conversely, does installing the parity jumper disable some other/better error checking hardware/firmware? Does Parity slow the [effective speed of the] disk down or use more bits on the disk to encode parity, thus lowering the total storage capability? In other words, for most reliable operation of the disk, should the parity jumper be installed or removed? -RDH -- A buddhist nudist RDH@SLI.COM | uunet!sli!rdh practices yoga bare. Robert D. Houk Software Leverage, Inc. 485 Massachusetts Avenue Arlington, Mass. 02174