The need for something more

When Xenon Disco did the first gigs we had a JostyKit light sequencer that was basically a solder-it-yourself circuitboard with a pre-amp, optocouplers and triacs that splitted the inputted audio spectrum into high-, mid- and low components and switched three triacs on/off. It was very cheep but it did the job at the time.

Everyone that was part of the initial xenon-crew was studying electrical engineering in the Swedish Vocational School in Vasa. As it quite soon became apparent that we needed a "real" computer-controlled light sequencer we decided to design our own system - for obvious reasons our philosophy was at that time "If you need it - build it".

The hardware

First version of the hardware was a quite crude design (called "the triac box") with 8 channels. It basically consisted of 8 optocouplers driving 8 transistors driving 8 triacs. Anyway it fulfilled our demands as we could switch sufficiently heavy loads and interface it directly with a Commodore 64 or 128. The triac box was mounted in the end of a long bar where 16 colored lights was mounted.

Why all these Commodore computers? Well, the Amiga and the PC had entered the scene, and there was a load of these old (=cheap) C64/128:s laying around. Plus the fact that I myself was quite familiar with doing I/O programming on it.

The light sequencer was then refined with a unit that was connected between the triac box and the computer which allowed more controlled switching for eliminating e.g. feedback into the audio system, (It was called "the diabolic box" due to the fact that it 1) was a lethal hazard with 220 volts if you removed the duct-taped on carboard lid from top of it, 2) it could easily be broken if you didn't handle it all too careful, sometimes boards were not event bolted down inside the box… but hey, it was always an ever evolving proto.)

The Diabolic box also got dimming-freatures, override-features with audio control (which served as backup incase of a computer breakdown:) Low-pass filtered pre-amps for the audio feed to the computer, etc ,etc. There was always a new feature being added, and the way I remember it we often did the sound checks and then started to play with the new features - we even did a bit of pre-gig-soldering sometimes to tune everything in. Almost all hardware designs was made by J.Åkerback, usually in his room at the boarding school.

The software

The software was made by M.Westman and P.Sandström on a Commodore 128D. It was developed over a time of seven years, but the most work was put down between the years 1991 and 1993.

LSQ

First prototype was finished around April 1990 and was called "LSQ 1.3", short for Light Sequencer version 1.3. It was made by P.Sandström. Put aside user-friendliness: It worked ! 8 channels individually controlled from your fingertips! About five months later version 1.4 followed.

Now M.Westman took over LSQ development, "windowized" it into version 2.x and added a bit of assembler to speed it up. LSQ was now becoming fast, robust & user friendly.

ProLSQ

In 1992 the name was changed to ProLSQ, (v1.0) 'cause we felt that the program we used was becoming quite professional :) At this time the demand for more output channels from the light sequencer was high.

The ProLSQ was mainly used for different kinds of running-light effects, but the on future channels we wanted gobos, pinspots, sweeping lights, etc. Using the same running-light scheme there didn't seem like an all too good idea.

ProLogic

The new software branch, ProLogic-C64C version 1.03, hit the stages. It used a C64 we found lying about. Software was made by P.Sandstrom. The big change with this program was that you were able to make individual, independent, sequences for every channel. Also control of the stoboscopes was handed over to the ProLogic. It actually looked quite cool when the bass beats trigged the xenon flash tubes :)

Going ProLSQ again

Now there was two completely different systems to keep track of… no good. We quite fast got rid of the C64 and incorporated the ProLogic into the ProLSQ, code instead M.Westman did all the work on the migration.

So this lead to ProLSQ (v1.1) getting a new cool "dual-cpu"-feature instead; you could now chain two C128 machines (a "master" and a "slave" machine). This way we could control 8+8 outputs from one console, whooa! The master machine sent pulses on one of its outputs to control the slave(s).

In 1993 M.Westman and J.Åkerback left Xenon Disco, and at that time it seemed like a good idea for me to gain full control over exactly how the light sequencing hard- & software worked, should it ever have needed service or updating.

LEC - Spring cleaning

At this time all unnecessary hardware which lacked documentation (and thus could not easily be repaired in the event of a failure) was discarded, and the ProLSQ was rewritten heavily into the new "LEC 1.00", short for Light Effects Controller version 1.00. In this version functions that was rarely or never used was disposed of. The maintenance functionality (editing of sequences, etc) was moved into a separate application.

In 1997 it was time to do some thinking again. The chained-computer approach had proven to be a bit unreliable. Most problems occurred when booting the Commodores up, it also begun to feel like a bad idea to carry around two computers instead of only one. Add to this that the disco was taken over by a new generation that needed a reliable and easy operated sequencer system. A version 2.00 was made for testing out hardware for the upcoming multiplexer.

LEC 320-MUX

The soul reason for the master-slave approach was that a Commodore64/128 had only (about) 8 outputs and we needed more. Ok, let's solve it with hardware then? In 1997 came the LEC 320-MUX 1.00, short for Light Effects Controller version 320 Multiplexer version 1.00. Here we emulated 16 channels by building a multiplexer in hardware. One pin out from the Commodore was used to latch 8 channels at a time. We now had a more fail-safe system with less hardware. Imagine the impact on the light sequencer system if we would have had two or more pins for latching!

The end

Furthermore two improved versions 1.01 and 1.10 of the LEC 320-MUX was issued in 1997. No more development on our light sequencer was made after these versions as it was now a fact that cheap hardware for doing way cooler things than our light sequencer ever did was available in the shops, thus "the need for something more" couldn't any longer be met by our faithful Commodores.

As far as I know the light sequencer is today trashed but I happended to stumble over the software when rescuing old floppys to CD-ROM and made this page as a tribute to the project. Also, I dare say that all of us who worked on the light sequencer hard- and software can today agree on that we learned a lot on the way. Add to this that we did what we liked most at the time; stood on stage, playing the latest music, getting paid for it. Should the originators of the light sequencer team up today with a similar project using today's available technology and the skills we have today we would certainly come up with something way cooler...

... but that's another story…

Peter Sandstrom

16:th of March 2001

To view the feature matrix, screenshots from the diffrent versions and download disk images executable in emulator, please click here

To get a glimpse of the various electronic designs that was developed in the "XenoLab" click here

Back to Xenon home page