The original IBM-PC's Parallel Printer Port had a total of 12 digital outputs and 5 digital inputs accessed via 3 consecutive 8-bit ports in the processor's I/O space.

• 8 output pins accessed via the DATA Port
• 5 input pins (one inverted) accessed via the STATUS Port
• 4 output pins (three inverted) accessed via the CONTROL Port
• The remaining 8 pins are grounded

25-way Female D-Type Connector

Various enhanced versions of the original specification have been introduced over the years

• Bi-directional (PS/2)
• Enhanced Parallel Port (EPP)
• Extended Capability Port (ECP)

so now the original is commonly referred to as the

Examples

• A Digital JoyStick • An LCD Module • Stepper Motor Control

• Analog-to-Digital and Digital-to-Analog Conversion

• Francis J. Deck's Two-Chip I/O Expander

• Jim Fuller's Robotics Resources include a Simplified Output Interface and a 4-way Input/Output Interface

• Kris Heidenstrom's LPTCAP parallel print capture system

• Kyle C. Quinnell's Building an 8-bit PC-Based Logic Analyzer

• Sebastian Dehne's Parallel port powerSwitch

• Controlling an LCD module

• PC-to-PC file transfer

• Data logging system for a PC

• Zhahai Stewart's IBM Parallel Port FAQ/Tutorial version 0.96

• Craig Peacock's Beyond Logic covers both Parallel and Serial Ports and more...

• Peter H. Anderson's Use of a PC Printer Port for Control and Data Acquisition

• Warp Nine Enginering's Introduction to the IEEE 1284 Parallel Port Standard

• more

last updated: 26-Jan-98 Ian Harries <ih@doc.ic.ac.uk>