>any valid MBR starts with AA55, so if no AA55, FDISK /MBR might be done >automatically. Am I correct, Eric?
Heck, no! Not at all! It ends with 55 aa, and even then, you know nothing about whether it contains a WORKING boot program. The MBR contains TWO things: The boot program and the partition data. FDISK had the VERY stupid function to delete BOTH and replace them with a fresh copy if the 55 aa was missing or if there was a disk read error. The latter reproduceably killed several PCs. Non-working can for example mean "can only boot CHS but the bootable partition happens to be beyond the first 8 GB". Working can mean a normal MBR, or EzDrive, OnTrack, DDO, boot loaders like Grub or Lilo or Gag (although I would REALLY recommend to install them in the Linux partition instead, as the MBR is an exposed place where FDISKs of all operating systems can screw things up), and so on. Note that if you can SEE The EzDrive or OnTrack or DDO MBR then you MUST NOT modify the partition table at all, because after BOOTING those, all data will look shifted by one cylinder from what you saw when you bypassed EzDrive / ... This also explains why it is a real pain to have to install EzDrive. It does not have an uninstall function either, but you could conceivably use a clever for loop with dd in Linux to shift everything back by one track. Whatever. Just use FDISK /MBR *only* in a manual way. Tell the user that he can use it if he installed DOS on a machine which NEVER booted any other OS before, and he experiences that just nothing happens at boot time, no message and stuff. Eric ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
