CHAPTER 10

Keyboard and Printer Interfacing

Matrix Keyboard

Flowchart

Keyboard Serial Transmission Format

Make and Break

PC Scan Codes for PC/XT

Combination Key Scan Codes for PC/XT

Extended Keyboard Scan Codes

Keyboard Status Bytes

Keyboard Cable Jack for PC

INT 09

INT 09 Summary

Keyboard Buffer

INT 09H Routine

INT 16H (part 1)

INT 16H (part 2)

PRINTER INTERFACE

DB25 (Male) Printer Connector

Centronics Printer Interface Specs

Timing Diagram for Printer

LPT Base Addresses

PC Printer Ports and Functions

Data, Status, and Control Ports

BIOS INT 17H

BIOS INT 17H (continued)

Inner workings of INT 17H

SPP

EPP

ECP

Buffering Data and Control Ports

Connecting to a LCD Module

Connecting a Stepper Motor to a Parallel Port

Buffering LPTs Data Port

LPT I/O Address

Printer Control Characters

Review (1)

Review (2)

Review (3)