• If the project is for a client or for the Web, the developer needs to identify means of delivering the product whether via server or media storage.


• The terms alpha and beta testing are used by software developers to describe levels of product development.


• Alpha releases- for internal circulation (team working on the project) only and passed among select group of mock users.


• Beta releases- is sent to a wider audience with the same limitation: this software may contain errors or bugs.


• It is important to provide well-written documentation about the installation process so that users have a clear step-by-step procedure to follow.

Compact Disc Technology

• A standard CD is 120 mm (4.75 inches) in diameter and 1.2 mm (0.05 inches) thick and is composed of a polycarbonate plastic substrate (under layer - this is the main body of the disc), one or more thin reflective metal (usually aluminum) layers, and a lacquer coating.


• As the CD spins, it reflects light from tiny infrared laser into a light receiver diode.


• The reflections are turns into data.


• Pits are 1/3 microns long, 1/2 micron wide and 1/10 micron deep.


• A CD can contain 3 miles of pits wound in spiral pattern from hub to edge.


• Photolithographic technique:
  1. A glass disc is coated with layer of photo resistant material 1/10 micron thick.
  2. A laser then exposes a pattern of pits onto the surface of the chemical layer of material.
  3. The disc is developed and silvered, resulting in the actual pit structure of the finished master disc.
  4. The master is then electroplated with layers of nickel one molecule thick one layer at the time until finished.
  5. The plastic disc is coated with thin aluminum layer for reflectance and lacquer for protection- that is the silk-screened label for marketing and packed for delivery.
  6. The activity needs to be accomplished in a particle-free clean room.

Compact Disc Standard

• 1979, Phillips and Sony launched CD technology to digitally deliver sound and music to the consumers. It is known as the Red Book Standard or Compact Disc Digital Audio standard. It defines the standard for today’s’ CDs.


• Yellow book: CD-ROM


• Green Book: CD-I (interactive)


• Orange Book: write-once, read only CD-ROMs


• White Book: VCD

Digital Versatile Disc

• DVD employs a different manufacturing process than audio and data CDs. It could store up to 15.9GB on a single disc on a double sided, Dual layered format (DVD-18).


• More common disc would be Single-Sided, Single-Layered discs offering 4.37GB of storage.


• There are three competing sets of standards for recording DVD: DVD-R/DVD-RW, DVD+R/DVD+RW and DVD-RAM.


• DVD standards are supported by the DVD Forum, DVD+ standards are supported by the DVD+RW Alliance.


• DVD RAM has better recording feature but it need specialized playback hardware.


• DVD-R/RW and DVD+R/DVD+RW are similar and can be played back on most DVD players.