In 1969, Apollo 11 astronauts blasted off for the moon carrying a "state-ofthe-art" computer called the AGC (Apollo Guidance Computer). With only 2 K of random access memory, 34 programmed operations, an 18-key keyboard, and a processor that poked along at 1 MHz, the AGC provided less computing capability than one of today's $29 hand-held scientific calculators, and certainly far less capability than your average desktop PC. In this section, you'll learn more about the capabilities of today's computers, find out how various components work, and learn how to decipher a typical computer ad.

Section A jumps right into data representation and digital electronics-the two major elements that make computers "tick." With this background, you can begin to make sense out of the bits, bytes, and megabytes that enter into just about every discussion about computers. Section B helps you answer questions like "How fast?" and "How much capacity?" in reference to microprocessors and computer memory. Section C focuses on computer storage so that you can understand storage technology and make decisions about storage devices for your computer. Section D describes keyboard, display, and printer technologies, then takes a look at the expansion bus and how to add peripheral devices. The TechTalk section delves into the details of how a microprocessor executes instructions.

When you complete this section you should be able to:

Explain why most computers are digital and how that relates to representing numbers by using 0 and 1 bits

Describe the role of a microprocessor's ALU, control unit, registers, and instruction set

List the factors that affect microprocessor performance

Explain how RAM works and how it differs from disk storage

List facts about RAM that are important to computer buyers and owners

Describe the difference between magnetic storage and optical storage

Use criteria such as versatility, durability, capacity, access time, and data transfer rate to compare storage technologies: floppy disks. hard disks, tapes, CDs, and DVDs

Describe the components of a computer's expansion bus, including various types of expansion slots and cables

Explain the factors that might help a shopper decide whether to purchase a CRT or an LCD monitor

Compare and contrast the technologies and applications for ink jet, solid ink, thermal, dye sublimation, laser, and dot matrix printers

Explain the hardware compatibility considerations, device drivers, and procedures involved in installing a peripheral device