文档介绍：
Parallel Port
Complete
Programming, Interfacing,
& Using the PC's
Parallel Printer
Port
r Includes EPP ECP
IEEE-1284
r Source code i n
Visual Basic
r User tips
INCLUDES
DISK
Jan Axelson
Table of Contents
Introduction ix
1 Essentials 1
Defining the Port 1
Port Types
System Resources 4
Addressing
Interrupts
DMA Channels
Finding Existing Ports
Configuring 6
Port Options
Drivers
Adding a Port
Port Hardware 9
Connectors
The Circuits Inside
Cables
Multiple Uses for One Port 11
Security Keys
Alternatives to the Parallel Port 13
Serial Interfaces
Parallel plete
Other Parallel Interfaces
Custom I/O Cards
PC Cards
2 Accessing Ports 17
The Signals 17
Centronics Roots
Naming Conventions
The Data Register
The Status Register
The Control Register
Bidirectional Ports
Addressing 24
Finding Ports
Direct Port 1/O 26
Programming in Basic
Other Programming Languages
Other Ways to Access Ports 31
LPT Access in Visual Basic
Windows API Calls
DOS and BIOS Interrupts
3 Programming Issues 39
Options for Device Drivers 39
Simple Application Routines
DOS Drivers
Windows Drivers
Custom Controls
Speed 45
Hardware Limits
Software Limits
4 Programming Tools 53
Routines for Port Access 53
Data Port Access
Status Port Access
Control Port Access
Bit Operations
A Form Template 60
Saving Initialization Data
Finding, Selecting, and Testing Ports
5 Experiments 85
Viewing and Controlling the Bits 85
Circuits for Testing
Output Types
Component Substitutions
iv Parallel plete
Cables & Connectors for Experimenting 99
Making an Older Port Bidirectional 100
Cautions
The Circuits
The Changes
6 Interfacing 105
Port Variations 105
Drivers and Receivers
Level 1 Devices
Level 2 devices
Interfacing Guidelines 110
General Design
Port Design
Cable Choices 112
Connectors
Cable Types
Ground Returns
36-wire Cables
Redu