Re (4): [Oberon] Native Oberon: Mounting an ISO9660 CDROM

[muller at inf.ethz.ch]

cglur at onwe.co.za wrote:
> Perhaps this IDE's master boot record can fix my:
> Disk: IDE0, 37GB, ST340016A
> IDE0#00  38166MB --- (Whole disk)
> 
> I'm guessing the MBR depends on the geometry ?
> My CHS is 16'383, 16, 63.
> It's not on this machine now, to use Partitions.Show detail ~

The MBR block contains two parts.  The first 446 bytes contain
the master boot loader (normally placed there by the drive 
manufacturer's format program), which loads the boot block of 
the first active partition.  The last 66 bytes contain the primary 
partition table, consisting of 4 primary partitions.

Since 12.02.01, the Partitions module has a WriteMBR command,
which can write a 512-byte file to the MBR without overwriting 
the partition table.  It only overwrites the first 446 bytes.

A short example of the use of this command is at:
  http://www.oberon.ethz.ch/partitions.html

If you want to restore the MBR of a disk without damaging the
partition table, you can use:
  Partitions.PartitionToFile dev#part filename 0 1 ~
to copy the MBR of an error-free disk and write it with:
  Partitions.WriteMBR dev#0 filename ~
on the broken disk.

You can find more on the MBR and partition table format at:
http://www.ata-atapi.com/hiwmbr.htm
http://www.ata-atapi.com/hiwtab.htm

Hope this helps.

-- Pieter

--
Pieter Muller, Computer Systems Institute, ETH Zurich / MCT Lab, Zurich
Native Oberon OS: http://www.oberon.ethz.ch/native/