1 / 6

Information and Communication Technology

Information and Communication Technology. File Access Modes Tsang Wing Luen S4C (28). File Access Modes. Sequential Access Mode Direct Access Mode Also called Random Access Mode. Sequential Access Mode. Not common Has to wind the tape until the desired record is underneath the read head

kailey
Download Presentation

Information and Communication Technology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Information and Communication Technology File Access Modes Tsang Wing Luen S4C (28)

  2. File Access Modes • Sequential Access Mode • Direct Access Mode • Also called Random Access Mode

  3. Sequential Access Mode • Not common • Has to wind the tape until the desired record is underneath the read head • Need longer time and unpredictable • Mainly used for back up and recover of database and files of servers • E.g. magnetic tapes

  4. Direct Access Mode • When the target location is moved underneath the read/write head, the reading or writing process operation can proceed.

  5. Hard disk • The most common storage • Most essential secondary storage device • Has high reliability, speed and capacity • Need shorter time and predictable to access data (access time: around 10ms) • Besides hard disk, floppy disk, optical disk and USB flash drive also support direct access mode.

  6. Optical disks • Operate in direct access mode • Limited in capacity and speed of data access • Used for storage of multimedia files • E.g. DVD-R, DVD-RW, CD-R, CD-RW

More Related