OSR5 FAQ

This article is from a FAQ concerning SCO operating systems. While some of the information may be applicable to any OS, or any Unix or Linux OS, it may be specific to SCO Xenix, Open There is lots of Linux, Mac OS X and general Unix info elsewhere on this site: Search this site is the best way to find anything.

I am trying to configure 30 GB or larger Hard Disk on SCO Unix.

After boot, I get messages like not a directory
boot not found
cannot open
Stage 1 boot failure: error loading hd(40)/boot.

You might be able to fix this by using the "biosgeom" keyword. See: https://aplawrence.com/cgi-bin/ta.pl?arg=109420 and https://aplawrence.com/cgi-bin/ta.pl?arg=104579.

This could also be due to an unsupported udma controller, see Do modern versions of SCO support IDE UDMA controllers?

David Font of Systime Computer Co Ltd provided this:

Configuring an IBM EIDE Disk in OpenServer5

Introduction

This document describes how to configure an IBM Deskstar 75GXP DTLA-307030 disk in OpenServer5. This disk is an EIDE type with capacity of 30GB. The Part Number is # 07N5639.

A PDF document, from ftp://ftp.pc.ibm.com/pub/pccbbs/options/d4q4bfl3.pdf, provides a description of the IBM EIDE model range, which includes the 30GB disk.

Background

Within the PDF document, locate the Specifications sheet and the Logical Parameters data. For the 30GB disk the number of heads is 16; the number of cylinders is 16383; the number of sectors per track is 63; the LBA?s value of 58600.

The BIOS settings for this disk should be set to NORMAL. The Number of Heads value, the Number of Cylinders value and the Number of Sectors per Track value (collectively known as the CHS) are used by the BIOS to pass into the Operating System as it begins to configure the disk. However the current Number of Cylinders value will only provide a maximum of 8.4GB capacity.

Procedure

When a disk is about to be configured either at the start of loading the Operating System or when mkdev hd command has been executed, the Hard Disk Drive x Configuration screen will display.

Select

 
1.         Display current disk parameters
 

This will display as follows:

Disk	Parameters	Values
1.	Cylinders	as per CHS	e.g.16383
2.	Heads	as per CHS	e.g. 16
3.	Write	Reduce	0
4.	Write	Recomp	as per CHS
5.	Ecc	0
6.	Control	0
7.	Landing Zone	as per CHS	e.g. 16383 or 16382
8.	Sectors/Track	as per CHS	e.g. 63

The Cylinders and Landing Zone values need to be changed to increase total capacity to 30GB. The LBA's values should be entered here.

Select 2. Modify current disk parameters

At prompt Enter a parameter to modify or quit to return

Select 1. Cylinders

Change to 58600

Select 7. Landing Zone

Change to 58600 (or 58599)

Select q to quit

When the divvy command is executed at the end of the configuring process, the disk capacity will show as 29534367

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