Lenovo ThinkPad 770E-ED TP 770X User's Reference that shipped with the system - Page 21

Identifying the Hardware Features 1 The coin screw can be changed to a security screw shipped with your computer to prevent others from gaining access to the hard disk in the hard disk bay. 2 The hard disk bay houses the replaceable hard disk drive. 3 The adapter bay is a slot for installing the DVD and Enhanced Video Adapter, an optional feature of your computer. 4 The serial number label identifies your computer. You might be asked for this if you get support from the help center. 5 The front infrared port allows your computer to communicate with other devices that have infrared data-transfer capabilities. 6 The security screws are hex-head screws that can be installed to prevent others from releasing the left and right release latches and easily gaining access to the battery bay and the UltraBay II. 7 The bottom compartment houses the DIMM memory slots and the backup battery slot. You can insert up to two DIMM memory cards into the memory slots to upgrade your system memory. The backup battery in the battery slot is used for retaining computer information in computer memory and also for running the time-of-day clock. Chapter 1. Getting Familiar with Your Computer 7