PC/AT Combo I/O Chip

This document provides comprehensive technical specifications, functional descriptions, and timing diagrams for the VL82C106 PC/AT Combo I/O Chip. The chip is designed to reduce motherboard component count by integrating:

• Two 16C450-compatible UART serial ports
• A bidirectional parallel printer port with Extended Mode
• A 146818A-compatible Real Time Clock (RTC) with 66 bytes of standby RAM
• A PC/AT- or PS/2-compatible keyboard/mouse controller
• Integrated Drive Electronics (IDE) bus control logic
• Seven programmable chip select registers for auto-configuration

The manual details pin assignments, signal descriptions, register maps (for both the keyboard controller and RTC), and AC electrical characteristics, making it essential for hardware designers implementing this IC on a motherboard.