Bertho, I spoke from the point of view of the device (the hard drive) - if the hardware that the device is attached to chooses not to expose all of the options that the device supports, there is little the device can do about that. In the case of your external storage somebody made a design decision that 4KB blocks were more desirable, and in a lot of cases that is true. But I'm quite sure that the underlying devices (hard drives) will support 512 byte sector sizes in emulation for a very long time.
To be able to share data on a hard drive directly between two different operating systems the format of the device and the layout of the filesystem on that device have to be understood by both operating systems. Linux and Windows have a clear advantage; there are lots of people working on them and they have the supporting code and operating system resources to do lots of transforms on the data. We are more limited in DOS - DOS expects FAT or an installable filesystem (network redirector interface). If you give DOS a block device (whether through BIOS or device driver) DOS expects 512 byte blocks. (The network redirector interface is a higher level file interface, so it does not have such problems.) If you want to write a block device driver for DOS to use with FAT you can accommodate any physical sector size you want - as long as the device driver hides that and gives DOS 512 byte blocks, you will be fine. The network redirector interface can do magic - it is often used to take the 2048 byte blocks of a CD-ROM and the ISO filesystem on it and present it to DOS in a way that can be used by DOS. The important part is that it doesn't try to present a CD-ROM and the foreign filesystem on it (ISO) as a block device to DOS; it is a higher level installable filesystem interface. Given enough code, you can have an IFS driver to read EXT2, EXT3, NTFS, etc. So the bottom line is that DOS will probably work just fine when natively attached to storage devices, and that will work for a long time. "Appliance" storage devices are going to break that if they can't emulate 512 byte sectors. I'm not entirely sure that Linux or Windows will let you create a 512 byte FAT style filesystem on storage that is using larger sectors. If they can do that and you want to share data with them on your DOS system by directly reading the storage, then it's time to start writing some device drivers. ;-0 Mike ------------------------------------------------------------------------------ RSA(R) Conference 2012 Mar 27 - Feb 2 Save $400 by Jan. 27 Register now! http://p.sf.net/sfu/rsa-sfdev2dev2 _______________________________________________ Freedos-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-user
