Index_O

---

O

Online UPS, 44

Operating systems

A+ Operating System exam objectives, 19–28

fundamentals, 274–276

logical memory, 94

multitasking, 277–278

testing tips, 299–301

version checking, 276–277

Optical mouse, 114

Optical storage devices, 180–182

Optomechanical mouse, 114

Oscillator, 64

OSI reference model, 225–227, 508

OSPF (Open Shortest Path First) protocol, 236

Output, defined, 131. See also I/O devices

Ozone filters, laser printers, 153

---