____ _ _ _ _ _ _ ____
| _ \(_) ___| |__ __ _ _ __ __| |___| | | |_ _| |__ / ___|___ _ __ ___
| |_) | |/ __| '_ \ / _` | '__/ _` / __| |_| | | | | '_ \| | / _ \| '_ ` _ \
| _ <| | (__| | | | (_| | | | (_| \__ \ _ | |_| | |_) | |__| (_) | | | | | |
|_| \_\_|\___|_| |_|\__,_|_| \__,_|___/_| |_|\__,_|_.__(_)____\___/|_| |_| |_|
i found this 8 inch floppy disk in a skip, many years ago (1998 or so),
from looking at the instruction leaflet in the box,
this disk was used to align the head(s) of a Dysan 360A or 360/2A 8 inch disk drive,
in conjunction with an oscilloscope.