Epson Endeavor - Manual (Page 75)

Your computer can hold up to three drives. There are two
horizontal drive bays and one vertical drive bay.
The upper horizontal bay contains the diskette drive that came
with your system. If your system came with only one diskette
drive, you can install an additional device of one of the
following types in the lower horizontal drive bay:
5 1/4-inch-wide diskette drive, tape drive, CD-ROM drive, or
other storage device
3 1/2-inch-wide hard disk drive with mounting frames
attached to it.
3-2
Installing and Removing Drives