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!!
If you're just looking for QUIZBOWL or PPORTBIT,
to the bottom:
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
If you're just starting out and don't want to write any software
use SEEBITS.EXE (Above)
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
port and "fixes and unscrambles" them so that Pins 10 thru 17 on the
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: 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
/ 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
is needed, use the full PARPORT software in PARPORT.ZIP. Here's
PPORTBIT works: You type a command on the command line (Or put the
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
connector pins 2 thru 8 respectively (Any pin from 18 thru 25 is
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
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
button first, and lights up the team's LED and makes a distinctive