Ch 2: Memory Access Time Flashcards
(13 cards)
What is Memory Access Time?
time required for processor to access data and instructions
Measured in fractions of a second
What is another way to describe the speed or efficiency of RAM?
Memory Access Time
Which data unit are RAM storage and disk storage measured in?
bytes
Which data units is storage capacity commonly measured in?
megabytes, gigabytes, and terabytes
How many bytes do most computers have enough memory to store?
millions or even billions
What amount of RAM might a typical desktop computer system today have?
8 gigabytes
Why are startup programs stored on ROM chips?
it is critical they are not erased from a PC
What is an example of a startup program?
the basic input output system or bios.
What is an example of a startup program on a Mac?
Open Phone
What is the purpose of Erasable Programmable ROM (EPROM)?
allows chips to be erased (when removed) and reprogrammed
enabled reusing a system chip but required removing it from the computer and using ultraviolet light
What is “flashing the BIOS”?
EPROM enabled reusing a system chip but required removing it from the computer and using ultraviolet light
What is the purpose of Electrically erasable programmable ROM (EEPROM)?
allows reprogramming of a ROM chip (without removal)
EEPROM allows upgrading a BIOS chip with a utility without removing it
What is Flash Memory?
A type of EEPROM
is read and written in blocks, not bytes, as is in RAM
Like EEPROM, flash memory can be reprogrammed a limited number of times, so it’s it is used mostly for storage, not as a substitute for computer memory
RAM flash memory is used in USB, flash and solid-state hard drives, digital cameras and audio players, cell phones and video game systems, and also Used to exchange data on printers, cameras, scanners and copier
