ParPort: PC Parallel Port Software

"You GOTTA Have Blinkin' Lights!"

YOU can use a PC Parallel Printer Port to light up LEDs and sense if switches are on and off. To get started, just plug a couple of visible LED's right into a printer parallel port connector, as seen above. (NOTE: Best to use a separate port card, NOT the one right on your motherboard. Or use any OLD PC for experimentation.) YOU can build BitMachines that make decisions or write your own software using ParPort support routines. And it's FreeWare: No registration, no Nagging!

Hey, it's 2011. Is there Still a DOS??? If you can get an OLD PC with a parallel printer port for free, give this a try:

-- FreeDOS is here: (CLICK) and FreePASCAL is here: (CLICK)

NOTE: DO NOT Install FreeDOS except on an old machine and when you know you will completely WIPE the Hard Drive!!


Get SEEBITS.EXE and start experimenting now: SEEBITS.EXE Size: 15 K

Get ParPort PC Parallel Port Software here: PARPORT.ZIP Size: 150 K

COMPUTER DEMOLITION! Take an old computer apart with kids. How-to manual. COMPUTER DEMOLITION Size: 300K

PR Crane: A computer-controlled crane made from an IBM Graphics Printer! PRCRANE.ZIP Size: 300K

(If you download this and use it in some way, or have any problems, please let me know, so I have some idea of who/how many are interested!)

If you're just looking for QUIZBOWL or PPORTBIT, scroll to the bottom:

PARPORT PC Parallel Port Software Info

These routines have been developed over several years of use with school kids, primarily in grades 5 to 8. The courseware that I put together is referred to as "Bits & Bytes". Sometimes kids get into a longer-term project called "BitMachines" where they design and build some funny computer-controlled machine. Recently we did a year-long project with 50 6th-graders in Vermont titled "The Engineering Design Process".

PARPORT utilizes an IBM-compatible machines PRINTER PORT, often called the PARALLEL PORT.

PARPORT 'fixes' the funny way the bits and ports were designed, specifically to control a printer.

All you need to do is think of your machine as having

  1. An 8-bit OUTPUT port, with the 8 bits connected to pins 2 thru 9 on the connector
  2. An 8-bit INPUT port, with the 8 bits connected to pins 10 thru 17 on the connector (Pins 18 thru 25 are GROUND).
You've probably heard of how weird the parallel port is! It's true, but this software fixes it by moving the funny input bits around and inverting those that need it. This level of software is for those who write their own programs in Turbo Pascal (From Borland) and want to control the parallel port.

If you're just starting out and don't want to write any software YET, use SEEBITS.EXE  (Above)

SEEBITS: Fullscreen Parallel Port Software

SeeBits: DOS Fullscreen Control and Monitoring of Parallel Port Bits with large 'Bits' that can be seen across a classroom

SeeBits uses a "Printer Port" (often called a "Parallel Port") SeeBits runs under DOS on any IBM-compatible computer. OLD XT or AT type machines are good, cost about $20 these days, and you can dedicate one to controlling projects, equipment or your home.

SeeBits is the simplest, beginning software to use to start. ALL it does is allow you to turn 8 OUTPUT bits ON and OFF, and display the state (ON or OFF) of 8 INPUT Bits. Later, you may want to SEQUENCE things, and perform LOGIC to be able to make decisions. For this you will need to write software of your own, or use a Sequencing program such as  BITMACH.

OUTPUT PORT: SeeBits uses output bits of a printer port for OUTPUTS to control External devices such as LED lights, beepers, relays or transistors. Pins 2 thru 9 on the printer port are used. The BIT numbers and PIN numbers may both be seen on the SeeBits screen bits.

INPUT PORT: SeeBits uses bits from two funny input ports on the printer port and "fixes and unscrambles" them so that Pins 10 thru 17 on the printer port appear as 8 available bits. NOTE: Bits 1 and 2 often "float" down (ON). You can connect 4.7K 'pullup' resistors from input pins to Pin 1 to fix this if needed.

OUTPUT CONNECTIONS are from Pins 2 thru 9 to GROUND (Use any Pin 18 thru 25).

INPUT CONNECTIONS are from pins 10 thru 17 to GROUND (Use any pin 18 thru 25).

NAMEBITS and BITMACH: State Machine Programming      Here:  BITMACH.ZIP

These are companion programs that create a state-machine programming environment that needs no compiler to write programs that run using bits on the parallel port. I call this the BITMACHINE. You can create many useful programs such as an alarm system, a 'Quiz Bowl' controller, sequential machines such as Traffic Lights or Washing Machines., a cable tester, or any other machine you can think up that uses logic and input and output bits.

NAMEBITS: NAMES the parallel port bits according to your use of them

BITMACH: Define, run and debug machine sequences that make decisions based on parallel port bits, timers, counters etc. Control output bits. Control program sequence.

Get PPORTBIT Software here: PPORTBIT.ZIP Size: 40 K This software lets you turn output bits on the Parallel / Printer port ON or OFF  from the command line in DOS or at a DOS prompt in Windows.  This is an easy way to get started controlling things with your PC.  For more complicated uses, or when more decision-making is needed, use the full PARPORT software in PARPORT.ZIP.  Here's how PPORTBIT works: You type a command on the command line (Or put the command in a 'batch' (.BAT) file.  You must know (1) What printer/parallel port you will use (LPT1 or LPT2 or LPTM), and (2) which bit (Zero thru Seven) you want to control. NOTE: Bits 0 thru 7 are connected to the port connector pins 2 thru 8 respectively (Any pin from 18 thru 25 is ground).
So, PPORTBIT is used this way:  PPORTBIT <port> <bit> <ON|OFF|FLIP>   Examples: PPORTBIT LPT1 4 ON  -or-  PPORTBIT LPT2 2 OFF
You can also do: PPORTBIT LPT1 CLEAR ALL to turn all bits off at once.  "FLIP" means to change the bit to the opposite state (INVERT it).
Drop us an email with any questions.

Get QUIZBOWL Software here: QUIZBOWL.ZIP Size: 40 K This software uses "BitMachine" State Machine programming sequences to implement a 'QUIZBOWL' game in which up to 4 teams compete to answer questions first. Each team has a pushbutton in front of them they push to commit to answer. The software detects which team pushed their button first, and lights up the team's LED and makes a distinctive beep.