RAM & ROM (Edexcel IGCSE Ict)

RAM

Spec point — 1.6.1

What is RAM?

• RAM (Random Access Memory) is primary storage that is directly connected to the CPU and holds the data and instructions that are currently in use(temporary)
• RAM is volatile which means the contents of RAM are lost when the power is turned off
• For the CPU to access the data and instructions they must be copied from secondary storage
• RAM is very fast working memory, much faster than secondary storage
• RAM is read/write which means data can be read from and written to
• In comparison to ROM, it has a much larger capacity
• RAM capacity can be increased to improve performance

ROM

Spec point — 1.6.1

What is ROM?

• ROM (Read Only Memory) is primary storage that holds the first instructions a computer needs to start up(Boot file)

• ROM contains the BIOS(Basic Input Output System)

• ROM is a small memory chip located on the computers motherboard

• ROM is fast memory, much faster than secondary storage but slower than RAM

• ROM is non-volatile which means the contents of ROM are not lost when the power is turned off

• ROM is read only which means data can only be read from

• In comparison to RAM, it has a much smaller capacity

• ROM capacity can not be increased

• Some types of ROM can be changed

  • EPROM- erasable programmable read only memory
  • EEPROM- electronically erasable programmable read only memory

Differences between RAM & ROM

Flash memory

Spec point — 1.6.3

What is flash memory?

• Flash memory is a type of EEPROM (Electronically Erasable Programmable Read Only Memory)
• Non-volatile
• Fast access times
• Low power consumption
• Used in solid state drives, USB drives and SD memory cards

Worked Example Explain one negative impact of a user decreasing the amount of RAM in a computer

[3]

Answer

• Programs will load more slowly / Fewer applications can be open at the same time [1]...
• ...as they are more reliant on being read from secondary storage / virtual memory / HDD / SSD [1]...
• ...which has slower read/write times than RAM [1]