Computers can also handle special functions like producing music, reproducing video clippings on the VDU, even though they are not normally programmed to do so. In such situations, you have to install a special piece of hardware on the motherboard, so that your PC is able to perform these functions. The special piece of hardware which is called an add-on card, is responsible for the communication between your PC and other electronic devices like TVs, VCRs, audio-systems, etc.
One such add-on card is the audio-card. This card allows audio speakers to reproduce sound/music based on instructions from the motherboard. It also allows you to control the volume and tone of the Sound/music, which is not possible using the in-built speaker. Popular brands of audio cards in the market include Sound Blaster .COVOX and Aztec.
Similar to the audio card is the video-card. It does a two-way transfer of images from the system unit to a TV/VCR for recording or playback. The text ( For example, title, cast names etc.) that appear in movies is made possible using this card. Computer Eyes and TARGA are the commonly-used video cards.
Multimedia relies on the ability of these cards to transfer sound and pictures to and from the PC and microphones, audio cassette players, speakers, VCRs and video cameras. Multimedia software lets you integrate voice and visuals into your programs. Such applications are used in training and in business presentations.