Charge-Coupled Device - CCD - digital camera sensor at the back of the lens, 2D barcodes - Quick Response  QR codes, UPC-A - Universal Product Code version ‘A’ Barcode, (UPC-A) /  (EAN) barcodes are used  - Used in retail and warehousing, Code 128b barcodes are used - Used in transport and shipment tracking, Guard Bars - barcode -left, right, centre markers, On a bar code - Left hand codes - all have an odd number of black bars, On a bar code - Right hand codes - all have an even number of black bars, non-volatile storage - Secondary storage that holds its data without power, Magnetic storage - for example floppy or hard disks, Optical storage - uses laser light such as CD-ROM, Solid state devices - Flash memory using floating gates, Primary storage - volatile storage such as RAM, ‘pit’ and ‘land’ - reflective and non reflective areas on optical media, advantage of an SSD - no moving read/write head, advantage of a HDD - cheaper per Tb for storage, Disadvantage of an SSD - Electrons leak over time, Disadvantage of a HDD - Seek and rotational delays, Latency - time taken to read/write disk data, Seek delay - time the HDD head takes to move across the disk, Rotational delay - time to spin to the correct sector , Transfer time - time to move the actual data,

Input, Output Storage

Skriv ut
Innebygd

Ledertavle

Visuell stil

Alternativer

Bytt mal

Gjenopprett automatisk lagring: ?