Manuals

System Board and Functions: Dell Dimension XPS 50/66 FS

System Control | Real-Time Clock | System Board Removal

System Control

Much of the control logic has been integrated into a single application-specific integrated circuit (ASIC), which has the following features:

• Cache memory controller
• Main memory controller
• System BIOS support logic
• Fast gate A20 and microprocessor reset logic
• Local bus controller
• Clock generation logic
• ISA bus state machine
• Data conversion logic
• Port B register
• NMI logic
• DMA controller
• Interrupt controller
• Counter/timer circuits
• Clock and wait-state control logic
• Configuration registers

Real-Time Clock

The RTC is provided by the MC146818. The clock is accurate to within 1 minute/month.

64 bytes of CMOS NVRAM are provided to maintain the clock and user-settable system parameters. Backup is provided by a 4.5-V alkaline battery.

System Board Removal

After removing the cover, cables, and all expansion cards, the system board can be taken out by removing 5 screws.