General System 4 Functional Description PAGE SUBJECT 4-1 INTRODUCTION 4-1 CPU BOARD 4-1 80186 Microprocessor 4-3 Memory Devices 4-3 Memory Management Unit (MMU) 4-4 Floppy Disk Drive 4-4 WorkNet 4-4 Z-80A I/O Processor 4-4 HARD DISK CONTROLLER BOARD ILLUSTRATION 4-2 Figure 4-1. System Block Diagram