IDE hard disc setup for SCO Unix on XEN-PC 590 (Jade)

This IPB supersedes IPB 3181 issued on 15 November 1994.

Related IPB's

Refer to IPB 3177 for a description of the setup required for the XEN-PC 560 Intel Revenge motherboard (RA product code).

IPB 3188 refers to the XEN-PC 486 Acer P2 motherboard (RC & RD product code) systems.

IPB 3189 refers to the XEN-PC 590 Jade motherboard systems from 4.02 BIOS and XEN-PC 560 Ruby motherboard (RG & RH) systems. Ruby based systems and Jade systems from BIOS 4.02 use a common SurePath BIOS. When such systems boot up a square is displayed in the top right hand corner.

Prior to installing SCO Unix onto the hard disc the BIOS setup should be run by entering <Alt>S at boot up to check the setting of the Large Disc Support option. This is found in the Advanced Configuration setup screen.

If the whole disc is required for Unix then enable Large Disc Support. Unix will recognise the disc correctly. For example, Unix will report the Quantum LPS 540 AT drive as 1120 cylinders during installation and in the Unix kernel boot-up screen.

If a DOS partition is required in addition to Unix the following procedure should be used:

1. Install the DOS partition with Large Disc Support disabled. Unix Support have verified such an installation with a 100Mb DOS 5 partition.
   
   
2. During the installation of Unix on the remainder of the disc you are asked if the disc parameters are to be changed. Answer yes to this question and change menu item 1, the number of cylinders, to the appropriate number. (Refer to the Insight CD-ROM for geometry's of other drives.) As an example, for the Quantum LPS 540 AT this is 1120. This will make Unix report the geometry that the disc offers rather than the reduced geometry that Unix obtained from the BIOS during installation. Using the Quantum 540Mb drive as an example these two geometry's are:

   1024 cyl. 16 heads 59 sectors = 472Mbytes
   1120 cyl. 16 heads 59 sectors = 516Mbytes
   
   It has been noted that not carrying out the above change to the disc parameters did not affect operation. However, we recommend making this change at installation time to enable correct reporting of the disc at Unix boot-up.

If DOS and Unix are installed with the Large Disc Support enabled then Unix will not boot, a "NO OS" error being produced when re-booting. The Large Disc Support could then be disabled, however Unix would then report the drive as having only 1024 cylinders.

This IPB supersedes IPB 3181 issued on 15 November 1994.

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