Chapter 2: The Computer's Memory

Flash memory- an erasable memory chip: 

• ranges from 16 MB to 1 GB 
• compact alternative to disk storage
• no moving parts
• designed for specific applications such as storing pictures in digital cameras 
• likely to replace disk and tape storage
• Used for phones, pagers, portable computers, handheld computers, and PDAs 

 

RAM (random access memory) 

• temporarily stores data and program instructions
• retrieves info
• memory turned off when RAM turned off

ROM (read only memory)-permanent information and start up instruction storage

CMOS (complementary metal oxide semiconductor)

• similar to RAM only consumes less/low energy

Buses, Ports, and Peripherals-transports information through the motherboard

Buses 

• 32 or 64 wires
• connected to expansion slots, storage devices in bays, and external buses

Slots - allows external devices (peripherals) to be added

-New laser etching technology called extreme ultraviolet lithography (EUVL) could reduce chip size and increase performance radically.

-Superconductors that transmit electricity without heat could increase computer speed a hundredfold.

-The optical computer transmits information in light waves rather than electrical pulses.

-A computer manipulates patterns of bits—binary digits of information.

-The CPU follows software instructions, reduced to strings of bits, to perform the calculations and logical manipulations that transform input data into output.

-Not all CPUs are compatible with each other.

-The CPU uses:

• RAM (random access memory) as a temporary storage area—a scratch pad—for instructions and data 
•   ROM (read-only memory), which contains unchangeable information that serves as reference material for the CPU as it executes program instructions

-The CPU and main memory are housed in silicon chips on the motherboard.