Thanks for quick reply. So too big, how big can I go and the CMD line (in FreeDOS) to achieve some sort of FAT12 drive (for my USB stick D:\ partition)?
For FORMAT testing, I have FAT12, FAT16 and FAT32 drives in my DOSEMU2 installation. Those are created by manually changing the partition types in diskimage files, which is a bit of an insider trick, but you should be able to do the same with FDISK on real hardware :-) My FAT12 drive is a bit smaller than 8 MB, the FAT16 and FAT32 drives are both circa 32 MB each. Note that there are different partition types for < 32 MB and > 32 MB and for CHS and LBA. I recommend that you use LBA where available. You can have FAT16 drives with up to 2 GB (4 GB with the non-standard 64 kB cluster size) and FAT32 drives must be at least 32 MB and at most 2 TB (Terabytes) for MBR partitioned drives with 512 bytes per sector. FreeDOS does not yet support other sector sizes and although a few bits of code are available, it does not yet support GPT style partitioning in the kernel. I think Bret's USB drivers do support GPT partitioned USB storage media, but you will probably hit other DOS limitations when attempting to have more than 2 TB in a single drive letter. Anyway, for your FAT12 question, create a partition of FAT12 type, then format that. Because the distinction below/above 32 MB (64k sectors) and CHS/LBA does not exist in FAT12 partition types, you should probably assume hat it has to be CHS < 32 MB, even though the theoretical limit is 128 MB (4000+ clusters of 32 kB each). In general, I recommend cluster sizes up to 4 kB, so you would keep your FAT12 drives below 16 MB and your FAT16 below 256 MB. For larger drives, FAT32 is a better choice, in particular if you have mostly small files. Remember that every file is rounded up to whole clusters when it comes to disk space allocations. Drives and/or BIOS will often support access with 512 byte sector size, so you probably will not have to worry about the lack of 4k sector size support in FreeDOS. However, you will often see GPT partitioned drives on modern hardware - see above - and UEFI only systems without a BIOS or CSM (compatibility layer to provide BIOS interface on UEFI systems). You cannot run FreeDOS directly on such hardware yet. There is a small discussion about how to use open source CSM or BIOS implementations to potentially run DOS on 2022 computers at the moment, but no succes stories to share yet :-) Regards, Eric _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
