Sony PCG-R505ELP - Manual (Page 129)

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 that the floppy disk is properly inserted into the floppy disk drive.
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