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Title: Reduce floppy disk size after formatting
Author: rodarima
Created: Sat, 29 Jun 2024 14:40:21 +0000
State: closed
The useful space to store files inside a floppy is less than the capacity of the floppy itself:
```
% mkfs.msdos -C floppy.img 1440
mkfs.fat 4.2 (2021-01-31)
% stat -c %s floppy.img
1474560
% mkdir floppy
% sudo mount -o loop,uid=$USER floppy.img floppy
% dd if=/dev/zero bs=1 count=100M of=floppy/test
dd: error writing 'floppy/test': No space left on device
1457665+0 records in
1457664+0 records out
1457664 bytes (1,5 MB, 1,4 MiB) copied, 0,912079 s, 1,6 MB/s
% echo $((1474560 - 1457664))
16896
```
It needs a bit more than 16K to store the FAT table, so round it to 32K to allow some clearance for changes in FAT header size.
```
% echo $((1474560 - 32*1024))
1441792
```
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