NEW 1.1.3 Input, output and storage

Which of the following is a disadvantage of virtual storage?

• A cloud provider can take responsibility for backup of your files

• If your connection to your virtual storage goes down you lose access to your files

• Files may be held in many locations

• You can spread your file load across different servers

Answer explanation

Virtual storage is any storage which may appear to be local but is physically located elsewhere, for example on a network server, remote building on in the cloud. While many cloud based providers are quite cheap there is often an ongoing monthly cost to storing your data, and this can be quite high if you want them to store large volumes of data. However, it often comes with additional benefits such as collaboration, automatic backup and file version history.

Which of these is not a characteristic of ROM?

• Small capacity

• Non-volatile

• Large capacity

• Holds the bootstrap

Answer explanation

Compared to the RAM, the ROM has a relatively small capacity. It stores the instructions for starting the computer.

A school with a limited budget is likely to use what type of storage on its file servers?

• Optical

• Solid state

• Magnetic

• Cloud

Answer explanation

Magnetic storage would provide a school with the highest capacity storage at the cheapest price per GB on the servers.

Which of these is an optical storage device?

• Hard disk

• Cloud

• DVD-RW

• Flash memory

Answer explanation

DVD-RW uses laser light, so it is optical. Hard disk uses magnetism so it is magnetic. Flash memory uses floating gate transistors so it is solid state. The cloud is typically using remote hard disk drives.

Which of these is not a property of flash memory?

• Durable

• Solid state

• Slower than a hard disk

• Stores the BIOS

Answer explanation

Flash memory is faster than a hard disk which is why computer users like to have an SSD in their computer. Flash memory is also used to store the user-configurable part of the BIOS.

A desktop PC with an internal single drive of 16TB is likely to be:

• Optical

• Magnetic

• Solid state

• ROM

Answer explanation

An 16TB drive is likely to be very expensive as a solid state drive, therefore a magnetic hard disk is the most likely type of secondary storage. Optical drives do not have 16TB capacity.

What is a purpose of the ROM?

• To store instructions for embedded systems

• To store the results of calculations from the ALU

• To store the operating system on a modern PC

• To store instructions for applications software on a PC

Answer explanation

One purpose of the ROM is to store the programs for an embedded system. Games cartridges might be an example where the game itself is held on the cartridge, with player saved data held on flash memory on the games console.

Which of the following is NOT a feature of virtual storage?

• All your files are located on your local computer only

• All your files can be backed-up automatically

• Collaboration on files is possible in real-time

• All your files are located on many remote servers

Answer explanation

Virtual storage is any storage which may appear to be local but is physically located elsewhere, for example on a network server, remote building on in the cloud. While many cloud based providers are quite cheap there is often an ongoing monthly cost to storing your data, and this can be quite high if you want them to store large volumes of data. However, it often comes with additional benefits such as collaboration, automatic backup and file version history.

What is meant by the term volatile in the context of memory?

• The changing state of the clock

• Data is lost when the power is turned off

• A description of ROM

• Data is stored on the hard disk

Answer explanation

Volatile means power is required to retain the data. This is because the RAM is made of electrical capacitors and transistors that lose their charge if not continually refreshed.

From lowest to highest, order these examples of storage media by their typical capacity. A solid-state drive in a mobile phone. A DVD-R to distribute a film. A hard disk in a desktop PC.

• Hard disk, DVD-R, Solid state

• DVD-R, Hard-disk, Solid-state

• Solid-state, Hard disk, DVD-R

• DVD-R, Solid-state, Hard disk

Answer explanation

Optical disks such as CDs and DVDs are very cheap but limited by capacity and their large physical size. Solid-state is the most expensive, but has the fastest data read/write speed. Hard disks are gradually being replaced by solid-state drives; however, they are much cheaper byte-for-byte and therefore usually have a higher capacity.