NEC Advanced Personal Computer Manuals

Table of Contents

• • 6

    Table of Contents
  • 14

    Preface

• 16

  Chapter 1 Hardware Overview

  • 17

    System Block Diagram

• 20

  Chapter 2 Processor Pcb

  • 20

    Processor PCB
  • 21

    Processor PCB Block Diagram
  • 22

    Mother Board/Card Cage Interface
  • 23

    Card Cage Socket Contact Assignments
  • 23

    Interrupt Lines
  • 27

    Processor Timing
  • 29

    RFSH Signal Timing
  • 31

    Device Interface Circuits
  • 32

    Microprocessor
  • 33

    Direct Memory Access
  • 33

    DMA Instructions
  • 35

    DMA Command and Mode Registers
  • 36

    DMA Request and Mask Register
  • 38

    Interval Timer
  • 38

    DMA Status Register
  • 38

    Interval Timer Block Diagram
  • 39

    Interrupt Control
  • 39

    Timer Commands
  • 40

    Interrupt Control Block Diagram
  • 41

    Interrupt Control Commands Summary
  • 43

    Interrupt Initialization Command Words
  • 44

    Interrupt Operation Command Words
  • 45

    Memory
    • 45

      System Memory Map
    • 46

      Main Memory
    • 46

      Main Memory Block Diagram
    • 47

      Battery-Backed Memory
    • 47

      Battery-Backed Memory Block Diagram
    • 48

      Read Only Memory
  • 48

    Parallel Printer Control
    • 48

      Interface
    • 48

      Programming Considerations
    • 49

      Parallel Printer Control Block Diagram
    • 50

      Parallel Printer Connectors Pin Assignments
    • 52

      Parallel Printer Interface Signals
    • 54

      Parallel Printer Controller Instruction
    • 55

      Parallel Printer Controller Interface Timing
    • 55

      Parallel Printer Controller Instruction Sequence
    • 56

      Parallel Printer Controller Interface at Paper Out Status
  • 57

    Keyboard
    • 58

      2.8.1 Keyboard Layout and Scan Codes
    • 58

      Keyboard Layout
    • 60

      Interface
    • 60

      Keyboard Interface
  • 61

    Calendar and Clock Generator
    • 61

      Keyboard Interface Lines
    • 62

      Circuit Description
    • 62

      Clock/Calendar Block Diagram
    • 63

      Clock/Calendar Instruction Format
    • 63

      Programming Considerations
    • 64

      Clock/Calendar Format
  • 65

    Jumper Settings

• 66

  Chapter 3 Controller Pcb

  • 66

    Mother Board/Card Cage Interface
  • 68

    Controller PCB Block Diagram
  • 69

    Crt Display Control
    • 69

      Buffer Memory
    • 70

      Character-Code Representation in the Character Code
    • 70

      CRT Display Control Block Diagram
    • 70

      Display Buffer Memory
    • 71

      Attribute Description for Character Attribute Code
    • 72

      Controller PCB
    • 73

      Programming Considerations
    • 74

      GDC I/O-Address and Bit Map
    • 75

      Contents of the GDC Status Register
    • 83

      GDC Command Constants
  • 85

    Crt Display Unit
  • 86

    Flexible Disk Drive Controller
    • 88

      Bit Description of the FDC Main Status Register
    • 89

      Programming Considerations
    • 92

      FDC Commands