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I put together a simple realmode bootloader, but when I try to put my kenel.bin onto the floppy drive it says "the disk in drive A is not formatted" and gives me that option to format it or not.

My bootsector ends with the standard Why would the floppy not let me write to it anymore? is the bootloader messing up the FAT table or am I writing to many/to few zeros to the end of the bootsector image?

If you overwrite the first 512 bytes with a bootloader that isn't FAT-compatible.. It won't be recognized as FAT formatted.

This will make writing files to your disk in the "conventional" way very difficult..

http://en.wikipedia.org/wiki/File_Alloc ... oot_Sector

You can find more by searching the Forums/Wiki & Google.. Have fun

01000101 wrote:Why would the floppy not let me write to it anymore?

Windows won't let you read the floppy as a FAT12 floppy because it isn't. Find the FAT12 spec and look for BPB.