Q: Why am I inserting disks upside down?
From Hardware
The RX50 floppy drive has been called Digital's "attempt at elegance." The dual disk drive makes use of a single spindle and head to read/write disks inserted in either the upper or lower drive. Since RX50 floppies are single sided, the head merely reads the underside of the disk. The upper disk is inserted normally and the bottom side is read. To read the bottom side of the lower disk, it must be inserted upside down.