Epson Endeavor - Manual (Page 31)

To insert a diskette into a 5.25-inch drive, hold the diskette with
the label facing up and the read/write slot leading into the
drive, as shown below.
latch
read/write
slot
Slide the diskette all the way into the slot. Then turn the latch
down to lock it in a vertical position. This keeps the diskette in
place and enables the read/write heads to access the diskette.
Note
Some 5.25-inch drives have a release button rather than a
latch.
I
I
When you want to remove a diskette, first make sure the disk
drive light is off. Then flip up the latch and carefully pull out
the diskette. Place it in its protective envelope and store it in a
proper location, such as a diskette container.
Using Your Computer 1-15