Dell OptiPlex GX1 Service Manual page 17

The OptiPlex NX1 system contains an integrated controller and diskette drive
connector but is not equipped with a diskette drive. If you run the diskette-
based diagnostics, this computer requires an external diskette-drive kit as
described in Chapter 2, "Basic Troubleshooting."
The OptiPlex GX1 and OptiPlex NX1 systems include an integrated high-
performance 64-bit accelerated graphics port (AGP) subsystem, implemented
on the system board, which drives an external SVGA monitor. The AGP con-
tains a dedicated bus that bypasses the PCI bus and allows for interconnection
of the video subsystem directly to the Pentium chip set for the extra-high per-
formance required for 3D video subsystems. This architecture also off-loads
the PCI bus providing greater performance for devices attached to the PCI bus.
The maximum supported resolution is 1600 x 1200 with 65,535 colors at
75 Hz. The SVGA subsystem consists of the following major components:
ATI Rage Pro (AGP 2X) video controller
4-MB synchronous graphics random-access memory (SGRAM) video
memory (expandable to 8 MB via a video-memory upgrade kit)
15-hole monitor port
The integrated audio controller is a single chip that connects to the ISA bus.
The audio controller has analog jacks for line-in and microphone input. The
single line-out output jack provides stereo output for a line-level input to an
external amplifier or drives stereo headphones. See "Technical Specifications"
found later in this chapter for audio jack input and output specifications.
The ATI multimedia channel (AMC) implements a local graphics bus that allows
external devices to attach directly to the graphics controller. The AMC allows
devices to transfer video stream data to the graphics controller, for example,
MPEG-2 decoding for digital video disk (DVD) applications, or to receive video
stream data from the graphics controller to the device, for example, TV-Out
circuitry, or to do both simultaneously. Most of the video stream data trans-
fers occur on the AMC without congesting the PCI bus bandwidth.
The 40-pin AMC connector, shown in Figure 1-12, consists of three ports into
the graphics controller: a digital video stream (DVS) port for video input into the
graphics controller, a multimedia peripheral port (MPP) for video input and out-
put from the graphic controller, and an inter-integrated circuit (I
serial control port for controlling the attached devices. A fourth port, audio
mixing bus (AMB), is not supported by the system. To route mixed audio from
an AMC-compliant adapter card to the system board, CD-ROM audio cables
must be attached from the adapter card's CD-ROM audio input and CD-ROM
2
C)-compatible
System Overview 1-5