Chapter 1, "System Overview": Dell™ Dimension™ P133v, P166v, and P200v

System Features | System Unit | Interrupt Assignments | DMA Channel Assignments

System Features

Advanced Expansion System | EIDE Subsystem | Hard-Disk Drive Options

In addition to the standard features found in a traditional personal computer, the Dell Dimension 133v, 166v, and 200v systems include the following new and/or advanced features:

• Optional 256 KB of pipelined burst SRAM.

• Math coprocessor functionality internal to the Intel® Pentium® microprocessor.
  
  
• An ISA and PCI expansion subsystem connected to the PCI bus.
  
  
• Two high-performance EIDE interfaces that each support up to two devices, for a total of four EIDE devices. Of these four EIDE devices, up to two can be 1-inch-high, internal EIDE hard-disk drives with capacities from 850 MB to 2.5 GB. Higher capacities will be offered as they become available.

• Memory that can be expanded up to 64 MB.

• A built-in SVGA subsystem with an integrated graphics accelerator that interfaces with the PCI bus.
  

Most of these features are briefly described in this chapter. For a complete list of System Features, see Technical Specifications.
When following the descriptions in this manual, assume that the locations or directions relative to the system unit are as shown in Figure 1-1.

NOTE: Some service procedures for mini tower systems recommend laying the system unit on its right side to improve service access, but the descriptions continue to use the directions shown in Figure 1-1.

Figure 1-1. System Unit Orientation
Figure 1-2. Front-Panel Features of the Desktop System
Figure 1-3. Internal View of the Desktop System
Figure 1-4. Front-Panel Features of the Mini Tower System
Figure 1-5. Internal View of the Mini Tower System
Figure 1-6. Back-Panel Features

CAUTION: To avoid possible data or file structure corruptions, the reset button should only be used when the system cannot be rebooted by pressing <Ctrl><Alt><Del>. Before you use the reset button to initiate a hardware reset, close any open application programs and files if possible.

CAUTION: Ensure that all expansion-card slots have either a card-mounting bracket or a metal filler bracket installed. Omitting these brackets can disturb the normal airflow in the system unit, resulting in possible damage to system components.

Advanced Expansion Subsystem

This computer system offers an advanced expansion subsystem that can support a mixture of traditional ISA expansion cards (called legacy expansion cards), Plug and Play ISA expansion cards, and PCI expansion cards. Either the ISA Configuration Utility (ICU) or the operating system provides the means to configure the various types of expansion cards and avoid resource conflicts that might arise.

After all legacy expansion cards have been configured with the ICU or by the operating system, the system automatically assigns any required memory space, IRQ lines, and DREQ lines to any installed Plug and Play expansion cards and PCI expansion cards the next time the system is booted.

The "Configuring Expansion Cards" section of the online System User's Guide provides instructions for using the ICU to configure the system.

NOTE: If you are using the Microsoft® Windows® 95 operating system, the functions provided by the ICU are handled by the Device Manager, which can be accessed by double-clicking the System icon in the Control Panel. See your Windows 95 documentation for instructions on using the Device Manager to manage resources and resolve conflicts. The expansion-card slots include three ISA expansion-card connectors and three PCI expansion-card connectors, resulting in a total of six expansion slots.

EIDE Subsystem

The EIDE subsystem includes two EIDE interfaces (primary and secondary), each of which can support up to two EIDE devices such as high-capacity EIDE hard-disk drives, CD-ROM drives, and tape drives.
When an EIDE tape drive or CD-ROM drive is connected to the same interface connector as a hard-disk drive, the performance of the hard-disk drive is degraded. Therefore, the primary EIDE interface should be used for connecting hard-disk drives only. Any EIDE tape drives or CD-ROM drives should be connected to the secondary EIDE interface.

NOTE: The externally accessible drive bays at the front of the system unit are normally used for diskette drives, CD-ROM drives, or tape drives. Hard-disk drives should be installed in the internal drive bays described in the next subsection, "Hard-Disk Drive Options."

Hard-Disk Drive Options
A 1-inch-high EIDE hard-disk drive is installed in the primary hard-disk drive bay in the card guide assembly at the front of the chassis. An optional 1-inch-high EIDE hard-disk drive can be installed in the secondary hard-disk drive bay located next to the 3.5-inch diskette drive.

For best results, any installed hard-disk drives should be connected to the primary EIDE interface and any other EIDE devices should be connected to the secondary EIDE interface.

System Unit

Power Supply | System Board

The following subsections provide service-related information about the system unit.

Power Supply

DC Power Distribution | DC Power Connector Pin Assignments

The 200-W power supply can operate from an AC power source of 115 VAC at 60 Hz or 230 VAC at 50 Hz. The power supply provides the DC operating voltages and currents listed in Table 1-1.

NOTE: The power supply produces DC voltages only under its loaded condition. The DC power cable connectors must be connected to their corresponding power input connectors on the system board or drives for these voltages to be measured.

Table 1-1. DC Voltage Ranges

DC Power Distribution

Figures 1-7 through 1-10 provide the following information about DC power distribution:

• Power-supply cable identification
  
  
• Typical DC power connections for diskette, tape, CD-ROM, and hard-disk drives
  
  
• Pin assignments of DC power connectors
  
  
• Power distribution to sockets and connectors on the system board

Figure 1-7. DC Power Cables
Figure 1-8. DC Power Distribution

DC Power Connector Pin Assignments

You can measure the power-supply output voltages at the back (wire side) of the DC power connectors without disconnecting them. Figures 1-9 and 1-10 show the wire side of the connectors.

Figure 1-9. DC Power Connector P1
Figure 1-10. DC Power Connectors P2, P3, P4, P5, P6, and P7

System Board

Main Memory | Configuration Jumpers

The subsections that follow provide service-related information about system board components.

Figure 1-11. System Board Features

Main Memory

The two DIMM sockets (BANK0 and BANK1) accommodate up to 64 MB of memory using SDRAM DIMMs. SDRAM DIMMs improve the performance of the computer's memory subsystem by reducing the need for wait states. SDRAM devices have a synchronous interface to the devices to which they are connected and are governed by the system clock. These features reduce wait states often required for conventional memory devices to ensure that timing signals have been set up correctly. In equivalent configurations, SDRAM DIMMs are faster than EDO DIMMs because of fewer wait states.

Configuration Jumpers

See "Jumpers/Switches/Controls".
Figure 1-12. Configuration Jumpers

Interrupt Assignments

DMA Channel Assignments