- The first step in the process of converting an analog signal into a
digital representation. Accomplished by measuring the value of the analog
signal at regular intervals (called samples). These values are then encoded to
provide a digital representation of the analog signal.
- The extremes of operating range wherein the output is constant, regardless
of changes in input.
- The ability to vary the information content of a program by changing the
amount of data that is stored, transmitted, or displayed. In a video image,
this translates to creating larger or smaller windows of video on screen
- Process of uniformly changing the size of characters or graphics.
- SCSI Configured Automatically.
- System control interrupt. A system interrupt used by hardware to notify
the operating system of ACPI events. The SCI is an active low, shareable,
- Small computer system interface. Pronounced "scuzzy." An I/O bus designed
as a method for connecting several classes of peripherals to a host system
without requiring modifications to generic hardware and software.
- Software development kit.
- Sequential Couleur a Memoire (Sequential Color with Memory). The
television standard for France, Russia, and most of Eastern Europe. As with
PAL, SECAM is based on a 50-Hz power system, but it uses a different encoding
process and displays 819 horizontal lines per frame at a scan rate of 25
frames per second (50 fields per second). See also NTSC and PAL
- Hardware or software functionality that interprets a time-stamped music
data stream and sends packets to music hardware as their time comes due.
- In terms of device stacking in ActiveMovie, indicates that a pin
represents possible connections that are attached to, rather than those that
attach. Compare with source.
- Simply Interactive PC. A vision guiding investments that Microsoft is
making in software and hardware advances to make the PC as simple, convenient,
and approachable as an appliance.
- Smart Battery
- A battery subsystem that conforms to the ACPI requirements and
implementation defined in Smart Battery Charger Specification and
- Smart Battery table
- An ACPI table used on platforms that have a Smart Battery subsystem. This
table indicates the energy level trip points that the platform requires for
placing the system into different sleeping states, plus suggested energy
levels for warning the user to transition the platform into a sleeping state.
- A two-wire interface based on the I˛C protocol. The SMBus is a low-speed
bus that provides positive addressing for devices, as well as bus arbitration.
- SMBus interface
- ACPI defines a standard hardware and software communications interface
between an operating system bus driver and an SMBus controller using an
- System management interrupt. An operating-system–transparent interrupt
generated by interrupt events on legacy systems. By contrast, on ACPI systems,
interrupt events generate an operating-system–visible interrupt that is
shareable (edge-style interrupts will not work).
- SMPTE timecode
- An 80-bit standardized edit time code adopted by the Society of Motion
Picture and Television Engineers. See timecode.
- 1) Microsoft Systems Management Server. Provides a centralized management
service for distributed systems. 2) Short messaging service.
- socket services
- In Windows, a protected-mode VxD that manages PC Card hardware. Provides a
protected-mode PCMCIA Socket Services 2.x interface for use by Card Services.
A socket-services driver must be implemented for each separate PC Card
controller that is used.
- software device
- A filter in kernel streaming and ActiveMovie that has no underlying
hardware associated with it.
- software modem
- Also host-based signal processing or pumpless modem. Performs
signal processing on the host CPU and implements the controller using V.42bis.
The modem hardware consists of a telephone-line interface and
digital-to-analog and analog-to-digital conversion circuitry. The hardware
does not contain a DSP or a microcontroller. Compare with
- Sound Blaster
- Hardware produced by Creative Labs, Inc., that represents for MS-DOS–based
games one of the major hardware interfaces for both audio and music
(specifically MIDI) data.
- In terms of device stacking in kernel streaming or ActiveMovie, indicates
that a pin represents possible connections that attach, rather than those that
are attached to. Compare with sink.
- Sony/Phillips Digital Interface. The current standard for digital
connection to consumer audio devices is the S/PDIF connector. Microsoft is
encouraging the use of USB or IEEE 1394 as the digital connection between
stereo equipment and PCs rather than adapting S/PDIF to meet PC needs.
- Service Provider Interface. Component in Microsoft networking, TAPI, and
other communications technologies.
- spin down
- A power-management capability in which a hard drive shuts down its spindle
- static resources
- Device resources, such as IRQ signals, DMA channels, I/O port addresses,
and memory addresses, that cannot be configured or relocated.
- static VxD
- A VxD that is loaded statically during system startup. A static VxD can be
loaded in a number of different ways, including device enumeration by the Plug
and Play static device enumerator.
- Still Image class in the WDM architecture. The class of filters that deal
with still-image capture. A WDM STI minidriver provides support for
still-image devices under the WDM still-image architecture.
- STI plug-in
- In the STI class architecture, a module that manages the translation of
standard DDI calls to device-specific sequences in order to support
vendor-specific device features.
- An object representing an entity on an adapter capable of receiving,
processing, or supplying data. Notice that a stream is identical to a WDM
Stream architecture pin. A stream can accept data from or supply data to the
processor, such as a stream representing an MPEG input, or can simply route
data through hardware, such as a stream representing an NTSC output jack on
the back of an adapter. The purpose of representing nondata hardware with a
stream is that the properties of the hardware can be controlled by software.
- stream request block
- (SRB) The fundamental streaming mechanism to control and make requests of
minidrivers. A set of SRBs are provided for each minidriver to access
particular capabilities of a given driver and are specific for each data
stream supported by the device. An SRB comprises a command and data associated
with that command. A HW_STREAM_REQUEST_BLOCK structure contains all
information relating to a specific SRB.
- Simultaneous voice/data. A technology used in TAPI-based modem technology.
- Super VGA. A video standard established by VESA to provide high-resolution
color display on IBM-compatible computers. The most commonly implemented SVGA
standard is 1024x768 pixels resolution.
- Also Y/C video. A video signal that separates the luminance and
color (Y and C) components of the signal for improved quality over composite
video. The type of video signal used in the Hi8 and S-VHS videotape formats.
It transmits luminance and color portions separately, using multiple wires,
thus avoiding the NTSC encoding process and its inevitable loss of picture
- A compression system that requires equal processing capability for
compression and decompression of an image. This form of compression is used in
applications in which both compression and decompression are used frequently.
Examples include still-image databasing, still-image transmission (color fax),
video production, video mail, videophones, and video conferencing. Compare
with asymmetrical compression.
- Any operation that proceeds under control of a clock or timing mechanism.
Compare with asynchronous.
- system board
- Also motherboard or planar. The primary circuit board in a
PC that contains most of the basic components of the system.
- system context
- The volatile data in the system that is not saved by a device driver.
- system devices
- Devices on the system board, such as interrupt controllers, keyboard
controller, real-time clock, DMA page registers, DMA controllers, memory
controllers, FDC, IDE ports, serial and parallel ports, PCI bridges, and so
on. In today's PCs, these devices are typically integrated in the supporting