Tandy 1000 HX Technical Reference Manual page 6

• TANDY COMPUTER PRODUCTS
1000 HX Main Logic Board
Contents
Section Page
Introduction 1
Specifications 3
Connector Pin Assignments 4
Option Card Description 8
Bus Interface Specifications 13
Signal Listing 13
System Timing 17
Theory of Operation 21
Main Logic Board 21
CPU Function 21
Non-CPU Function, Main Logic Board 21
Processor Address/Data Interface 21
CPU Control Signal Generation 24
IFL Equations 25
System Control Signal Generation 25
Bus Specification 25
Interrupt Function 28
Bus Interface 30
Keyboard/Timer/Sound Timer Circuits 30
Keyboard Interface 30
Timer Function 32
Sound Function 32
Joystick Interface 35
Printer Interface 35
Floppy Disk Controller Interface 38
Video System Logic 39
Main System Board RAM Timing 42
I/O Map Summary 45
Video/System Memory Address Map 62
Schematic Diagrams 63