DISCO: DISplay COmmander

Print stuff on a geeky LC-Display connected to your Linux workstation 


My olde display:

Copyright C.Bingel 2008

Last updated 2008-02-25

"Disco" is software for controlling a HD44780-based LC-display that you connect to your PCs printer port. The software is primarily for Linux and is developed on RedHat 7.0 (which really shouldn't matter). The communication between the server process and the clients uses an arbitrary UDP-port (default 5252). The hardware is quite easily built yourself. And almost all smaller LCD's that you can buy are actually based on the HD44780-chip.

Disco has the following built-in features:

  • Print text-string at coordinate
  • Clear display
  • Reinitialize display
  • Manage scrolling text with several concurrent scrolls at different speeds, directions, sizes and positions.
  • Simple password protection
  • Define up to eight own characters (only through perl-module Disco.pm)
  • Designed to have a small "footprint" (the executable is only ~11kb)

The software consists of:

  • disco, which is the daemon program that runs in the background and controls everything
  • lcdcommand, a rudimentary commandline client
  • Disco.pm, a Perl-module for controlling the display from a Perl program
  • Swedish.pm, a Perl-module for creating and remapping swedish characters åäöÅÄÖ, which are normally not supported by the hardware
  • example.pl, simple example perl program


A simple drawing of the hardware:

A more thorough documentation of the HD44780 can be found here.


This software is released under GNU General Public License

Release history

v1.3 Fixed un-smooth scrolling while writing a lot to other parts of the display
v1.2 Experimental version, never released
v1.1 Added support for own-defined characters and a perl-module for adding swedish characters (åäöÅÄÖ) to the display's character-set
v1.0 First public release