Glossary

TAPE DRIVE INTERFACES
The hardware and software used to establish communication between a host and the device.

ATAPI (AT attachment packet interface) – A command protocol used for accessing IDE peripheral devices.

Floppy – A physical interface between the host computer and backup device enabled through a floppy disc controller.

Parallel – An interface option that allows the user to connect a limited number of PC peripherals to each other.

TAPI
Abbreviation of Telephony Application Programming Interface, an API for connecting a PC running Windows to telephone services. TAPI was introduced in 1993 as the result of joint development by Microsoft and Intel. The standard supports connections by individual computers as well as LAN connections serving many computers. Within each connection type, TAPI defines standards for simple call control and for manipulating call content.

The Telephony Server Application Programming Interface (TSAPI) defines similar capabilities for NetWare servers.

Telephony
The science of translating sound into electrical signals, transmitting them, and then converting them back to sound; that is, the science of telephones. The term is used frequently to refer to computer hardware and software that performs functions traditionally performed by telephone equipment. For example, telephony software can combine with your modem to turn your computer into a sophisticated answering service. Voice mail is another popular telephony application.

Temporal scalability
A type of scalability in which an enhancement layer uses predictions from a pel derived from a lower layer using motion vectors.

3:2 pull-down
A method for overcoming the incompatibility of film and video frame rates when converting or transferring film (shot at 24 frames per second) to video (shot at 30 frames per second).

The first film frame is actually exposed on three video fields, and the next film frame is exposed on two fields, the next film frame on three fields, and so on. Thus, two of every five video frames will consist of fields that contain information from two different film frames. The resulting effect is noticed as flicker during freeze frame use.

Terminal Adapter
A device that connects a computer to an external digital communications line, such as an ISDN line. A terminal adapter is a bit like a modem, but whereas a modem needs to convert between analog and digital signals, a terminal adapter only needs to pass along digital signals. As ISDN becomes more common, future computers will probably have terminal adapters built in. Currently, though, you need to purchase a separate terminal adapter if you want ISDN access. You can get an internal adapter or an external adapter than connects to your computer's serial port.

Texture mapping
The process of taking a picture, and drawing it onto a polygon. This can be used to add emblems, textures, or pictures to the rendered polygons.

Texture Thrashing
Constant swapping of video memory content to replace old textures with new ones requested by the application, causing a performance slowdown. Having more video memory and AGP helps eliminate this problem.

Texture Transparency (color-keying)
If a texture has a color-key color, then that color will not be rendered. As an example, this could be used for rendering text or objects with holes in them, such as a car door with an open window.

Time code
A frame-by-frame address code time reference recorded on the spare track of a videotape or inserted in the vertical blanking interval. The time code is an eight-digit number encoding time in hours, minutes, seconds, and video frames.

Time code generator
A signal generator designed to generate and transmit SMPTE time code.

Top field
One of two fields that comprise a frame of interlaced video. Each line of a top field on a screen is located immediately above the corresponding line of the bottom field, so that the lines of the two fields interlace.

Triangle setup engine
Special circuitry in the graphics chip that computes the mathematical aspects of what is needed to draw 3D images on the screen. This frees the CPU to perform other computations.

Triple buffering
Triple buffering is a technique of dividing the frame buffer into three areas: two drawing buffers and one display buffer. This allows the application to display a frame of animation from one buffer while drawing the next frame into the other buffer and then start rendering in the third buffer while the other two buffering are still in use, therefore further increasing performance.

Tri-linear filtering
A combination of bi-linear filtering and mip-mapping which enhances even more the quality of texture mapped polygons. For each polygon that is rendered, the two "MIP maps" that most closely match the polygon size will be used to compute pixel colors that are the most realistic. This technique is superior to both bi-linear and mip-mapping.

TRAVAN STADARDIZED MEDIA FORMATS

TR-1. Provides 400 Mbytes of uncompressed capacity, or up to 800 Mbytes of compressed capacity.

TR-3. Provides 1,600 Mbytes of uncompressed capacity, or up to 3,200 Mbytes of compressed capacity.

TR-4. Provides 4 Gbytes of uncompressed capacity, or up to 8 Gbytes of compressed capacity.

TR-8. Provides 10 Gbytes of uncompressed capacity, or up to 20 Gbytes of compressed capacity.

TSAPI
Short for Telephony Server API, an API developed by Novell and AT&T that enables programmers to build telephony and CTI applications. TSAPI is similar to TAPI, which was developed by Microsoft and Intel. But whereas TAPI has been implemented for the Windows operating system, TSAPI runs on Netware platforms. Another key difference is that TAPI can be used for both client - and server -based applications whereas TSAPI is strictly a server API.