Dell OptiPlex G1 Service Manual page 14

1-4 Dell OptiPlex G1 Managed PC Systems Service Manual
The OptiPlex G1 systems are equipped with an integrated diskette/tape drive
controller (PIIX4e) that can support a maximum of two non-EIDE diskette and
tape drives via a 34-pin DSKT connector located on the system board. The low-
profile chassis can accommodate only one external drive device (diskette drive
or tape drive). Other chassis configurations can accommodate two external
drive devices.
NOTE: If the diskette drive and tape drive are both attached to the diskette
drive controller on the system board, only the diskette drive is configured in
the System Setup program as Drive A or Drive B. The tape drive is then listed
as Not Installed (under either the Drive A or Drive B category).
The OptiPlex G1 systems include an integrated high-performance 64-bit base-
line accelerated graphics port (AGP) subsystem, implemented on the system
board, which drives an external SVGA monitor. The AGP contains a dedicated
bus that bypasses the PCI bus and allows for interconnection of the video sub-
system directly to the Pentium II chip set for the extra-high performance
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 resolutions include 1600 x 1200 pixels with 256 col-
ors noninterlaced and 1024 x 768 pixels with 65,536 colors noninterlaced. The
SVGA subsystem consists of the following major components:
ATI Rage II C (baseline AGP 1X) video controller
2-MB synchronous graphics random-access memory (SGRAM) video
memory (expandable to 4 MB using a video-memory upgrade kit)
15-hole monitor port
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), receive video
stream data from the graphics controller (for example, TV-Out circuitry), or do
both simultaneously. Most of the video stream data transfers occur on the
AMC without congesting the PCI bus bandwidth.
The 40-pin AMC connector, shown in Figure 1-11, 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 mix-
ing 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
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C)-compatible