Making Sence Of IBM Scsi Hard Drives IDs - Techist - Tech Forum

Go Back   Techist - Tech Forum > Computer Hardware > Hardware Repairs and Troubleshooting
Closed Thread
Thread Tools Display Modes
Old 09-05-2006, 10:37 PM   #1 (permalink)
Imperial Space Womble
Harper's Avatar
Join Date: Jan 2004
Location: Australia
Posts: 6,903
Question Making Sence Of IBM Scsi Hard Drives IDs

I am currently putting together a computer with 2x IBM 9Gb SCSI Hard drives.

I have located the pin to set the SCSI ID, but I am still trying to work out how IBM comes up with these SCSI ID Numbers.

The pins are follows
1 ID Bit 3
2 ID Bit 2
3 ID Bit 1
4 ID Bit 0
5 Enanble Auto Spin
6 S/E Mode
7 Disable Unit ATTN
8 IT Sync Nego
9 Auto Start Delay
10 Delay Star 6 / 12
11 Disable Parity
12 Led Out

Jumpers on 5 only = SCSI ID 0
Jumpers on 5 and 4 (BIT 0) = SCSI ID 1
Jumpers on 5 and 3 (BIT 1) = SCSI ID 2
Jumpers on 5 and 2 (BIT 2)= SCSI ID 4
Jumpers on 5 and 1 (BIT 4)= Does not detect
Jumpers on 2 and 3 (BIT 2 & 3)= SCSI ID 6

Now normally I am used to the Seagate Drives where you add up the bits.
However this older IBM Drive seems to be defying that rule.

Some my question is this. What algorithm does IBM SCSI Hard Drives use to work out SCSI IDs?

Also, can some one explain to me the
* S/E Mode
* Disable Unit ATTN
* IT Sync Nego
* Auto Start Delay
* Delay Star 6 / 12
* Disable Parity
* Led Out


Main Rig - AMD FX-8350x8 4.0Ghz CPU, 4x 8Gb (32Gb) DDR3 Ram, Gigabyte GA-970A-D3, GeForce GT 970 4Gb, 1x 256Gb SSD\8Tb (3+2+2+1) SATA HDD, DVDRW, SB X-Fi, Win 10 (64-bit)
Asus N61JV-JX231V - Intel Core i5 3437u (1.9 - 2.4 GHz), 12GB, 640GB, 16" Display, nVidia 325M 1Gb, DVD-RW, Win 10 (64-bit)
Mobile Phone : Samsung Galaxy 5 Note SM-N920IConsole : Play Station 4
Harper is offline  
Old 09-06-2006, 09:18 AM   #2 (permalink)
Lord Techie
Nitestick's Avatar
Join Date: May 2005
Location: смерти для спаме
Posts: 8,473

gahhhh. peculiar. don't suppose it's binary :/

Visit my website -
"Guitar is cool. If you donít think the guitar is cool, then youíre stupid. And I will fight you! " - Brendon Small
I'm sorry but I do not accept support requests via IM, email, or personal messages
You can contact me for Forum related issues via PM only.

Nitestick is offline  
Old 09-06-2006, 02:18 PM   #3 (permalink)
Junior Techie
Join Date: Sep 2005
Posts: 77

Yes, it is like
off,off,off off (0000) = ID0
off,off,off,on(0001)= ID1
and so on:
ID bit 3 is for 68-pin hdd's only (at least for very old drives that i have)

BTW, auto-delay is very practical feature.
I had at some time 6 SCSI drives on one pc, and w/o delay all drives tried to start up immediately after power ON - as a result PSU overloaded and switched off after 1 second. After i put different delay for each hdd - all worked fine:-)
junglemike is offline  
Old 09-06-2006, 02:43 PM   #4 (permalink)
Monster Techie
Join Date: Mar 2004
Posts: 1,400
Send a message via AIM to ATIRAGEPRO Send a message via Yahoo to ATIRAGEPRO
Cool "00110001-00110011-00110011-00110111-..."


Originally posted by bonehelm

I just found out I\'ve been using direct X 8.1 since its out.
He who knows when enough is enough will always have enough... - Lao Tzu
ATIRAGEPRO is offline  
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 09:32 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.