Sony PCG-R505ELK - Manual (Page 183)

Troubleshooting Drives, PC Cards, and Peripheral Devices
My floppy disk drive cannot write to a floppy disk.
 If the floppy disk is write-protected, disable the write-protect feature or use a floppy disk that is not
write-protected.
 Verify the floppy disk is properly inserted into the floppy disk drive.
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