AMSTRAD cpc 6128 User Instruction page 26

Some other compact floppy discs employ a small plastic lever located in a slot at the
left hand corner:
Write Protect
hole
(CLOSED)
To open the Write Protect hole on this type of disc, slide the lever towards the middle
of the disc, using the tip ofa ball-point pen or similar object:
Slide Lever
towards middle
of disc
Write Protect
hole
(OPEN)
Note that regardless ofthe method employed to open and close the Write Protect hole,
opening the hole in all cases facilitates protection against overwriting.
IMPORTANT
Always ensure that the Write Protect holes on your master CP/M system discs
package are open.
Foundation Course Chapter 1 Page 13