The OP did not make it clear why he wants "actual DOS". Perhaps some users night believe that the old DOS has primitive utilities that can better manage the hard drive. Not so.
Quite right, and I do agree with you here. I don't think I would ever say fdisk is easier to use- or understand- then something like Disk Management or GParted, unless one has already had experience using it.
These utilities wee written before significant changes were made in Hared Drive geometry and do not perform as the user might wish.
"These utilities"; they only talk about fdisk, and there is no significant danger from running fdisk on a drive, since it will not rewrite the boot code of the MBR, only the partition table.
The MAR is not just an area one the hard drive where some address are stored.
I never said it was. It is one area of the hard drive, though. the first sector of the drive, to be exact. Exactly 512 bytes. The offsets of important data are in fact standardized. All MBR's will have the Partition table (4 16-byte entries) at offset 446 within the sector. This is never different, regardless of the operating system. All that changes is the bytes before that, which determine the actual code used to start the boot loader itself. NT's boot loader differed from Win9x/MSDOS because it needed to have rudimentary support for NTFS to be able to find the boot loader, additionally it needed to know to look for NTLDR. Windows Vista's MBR boot code differs from XP and earlier in that they changed the boot loader to bootmgr, which has far more capabilities than NTLDR. Either way, the only task of the boot code in the MBR is to start this boot loader. That's it. It doesn't determine or change the "layout" of data on the drive, excepting of course the partition table.
There are rules as ton what can be placed there.
Yes. That's what I've been saying.
The rules have changed.
No they haven't. The code area of the MBR is still the first 446 bytes. the partition table is still 4 16 byte entries. the MBR signature that follows is still 2 bytes. What rules have changed with Vista? none- the only difference is that there is a different boot code to look for the new boot loader. Does the boot loader operate differently? Of course. But GRUB also operates differently from NTLDR and LILO operates different from BOOTMGR, but for some reason nobody is saying that a tool like GPARTED will cause the MBR to become "corrupted".
The rules are not consistent
Yes. they are really quite simple. Certain data is stored at specific offsets. 4 partitions per drive. the size of logical drives in the extended partition(which can be used to work past the "4-partition limit" are stored in EBR (Extended Boot Records) within the Extended partition. This has not changed with Vista.
The full set of rules is not seen by a casual examination of the area.
Yes, they are. the fact that the Vista and XP MBR's both conform to the given
standard for MBR layout sort of confirms that there is a full set of rules and they are being used by both operating systems.
The rules have been a moving target.
They were never a moving target. In fact, the layout of the MBR has been entirely unchanged since MS-DOS 2.00 when the original Hard disk support was added. Probably earlier. No Operating System that runs on a PC has used a on-disk format that didn't have an MBR. This includes Vista x64 when the drives are partitioned using GPT, since those drives also have a valid MBR- GPT acts as an extension.
That is why the GUID is now the way to go.
GPT is the preferred choice over the longer course simply because it extends the limitations of MBR. with MBR, no one partition can exceed 2TB in size, and no one partition can have an offset larger then 2TB from the start of the disk. needless to say this causes problems when you have drives larger than 2TB, which are starting to become available on the consumer market. It also adds redundant partition tables to mitigate the issues with the MBR's partition table (which, to repeat, is always at offset 446 and is always 16*4 bytes in size), where there was only one copy and if it got corrupted for any reason the disk was pretty much unsalvageable (without tools like MIRROR, of course). From the looks of things GPT merely brings to the lower level structures of the disk what file systems like NTFS, HPFS, Ext2/3/4 and so forth have been providing as file systems for years- that is, larger sized partitions, more partitions, and better resilience.
