Memory and Storage Flashcards
What is a memory unit and what does it store?
A memory unit is the collection of storage units or devices together and stores the binary information in the form of bits.
What are the two types of memory and what do they mean?
Volatile and Non-Volatile. Volatile means it loses data when the power is off, it is a type of primary storage. Non-Volatile means the data is kept when the power is turned off, it is a type of secondary storage
What is the meaning of primary and secondary storage?
Primary storage stores small amounts of data and
information that will be immediately used by the CPU.
Secondary storage (also called mass storage) stores much
larger amounts of data and information (e.g., software
applications, databases, photos) for extended periods of
time
What are the three types of information that is stored in primary storage?
Data to be processed by the CPU, Instructions for the CPU as to how to process the data and Operating system programs that manage various aspects of the computer’s
operation.
What are the main types of primary storage?
Registers, RAM, ROM and cache memory
Define Registers.
Registers are part of the CPU with the least
capacity, storing extremely limited amounts of instructions
and data only immediately before and after processing
Define Cache Memory.
A type of primary storage where the
computer can temporarily store blocks of data that are used
more often (to aid performance)
Define RAM.
Stands for Random Access Memory. The part of primary
storage that holds a software program and small amounts of
data when they are brought from secondary storage. RAM is
also called main memory or working memory
Define ROM.
Stands for Read Only Memory. A type of primary storage
where certain critical instructions are safeguarded. The
storage is non-volatile and retains the instructions when the
power of the computer is turned off
Explain Registers.
- Single storage locations within the CPU used for a particular purpose
- Used to hold a binary value temporarily
- Manipulated directly by the Control Unit
- Each register is wired within the CPU directly (no address needed)
used for specific function - Size measured in bits or bytes (not MB/GB like other memory types)
- Can hold data, an address or an instruction
Explain Cache Memory.
- Cache memory is extremely fast memory that is built into
the CPU, or located on a separate chip close to the CPU - The CPU uses cache memory to store instructions/data that
are repeatedly required to run programs, improving the
overall system speed - This saves the CPU from fetching the instructions/data from the main memory which is slower
What are the two types of RAM?
Static RAM (SRAM) and Dynamic RAM (DRAM)
Explain SRAM.
SRAM is the fastest type of RAM but is more expensive. It is mainly used in registers and cache memory.
Explain DRAM.
DRAM is cheaper than SRAM due to its simpler design. It also requires more power and generates more heat. The main memory used to store instructions and data is DRAM.
Explain ROM.
- ROM holds programs and data permanently even when
computer is switched off - The contents of ROM are fixed at the time of manufacture
- ROM chip also holds BIOS software, which is the first code to run when the computer is powered on
- Stores a program called the bootstrap loader that helps start up the computer
- Different types of programmable ROM: PROM (Programmable ROM), EPROM (Erasable PROM), EEPROM (Electrically EPROM)
