Sony PCG-FXA63 - Manual (Page 154)

Troubleshooting Floppy Disk Drives
Why is the drive unable to write data to a floppy disk?
The floppy disk drive cannot write data to a disk if it is inserted into the drive improperly. See To insert a disk for
instructions on how to insert the disk properly.
If the disk is inserted properly and you are still unable to write data to it, the disk may be write-protected. You can either
use a floppy disk that is not write-protected or disable the write-protect feature.
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