CYGN-B

[Greg]

From Brian:

Yes that's the master encoder from Studio A. There were a number of encoders, but only the one in Studio A encoder had the filters and stuff to generate signals from the sound track, etc. The others were just a variation on the theme on the part in the photos with the sliders and switches. The 351 data channel consisted of 20 bytes of data repeated every every 25 milliseconds. Some of the DOG routines were triggered - like popcorn. It allowed you to jump to a new offset on each drum beat.


It turns out the Laserium business model of a single laserist performing live wasn’t the way Laserium began. In the beginning Ivan (Dryer) and Charlie (McDanald) had 4 friends controlling the x and y axis sliders to control the gain for each image used in the Blue Danube. If they had to pay six laserists to do each show – well, forget commercial success. Charlie once told me that one of the smartest things Laser Images' did was the decision to emulate those other hands. They couldn’t record the relatively high bandwidth imagery, but they could record the low bandwidth voltages the sliders generated. This left the laserist to control imagery, color modulation, joystick, and intensity modulation. It turns out the recording of those ghosts moving the sliders complemented not just the imagery originally intended, but often complimented things nobody had thought of yet. The recorded portion of the show became something akin to the score in an interpretive dance piece. (An interpretive dance score tells the dancers where to move on stage - not how to dance. Some people who have studied music visualizations talk about painting with light, Laserium was more about dancing with light.) The data track adjusted the size and position and other important things that allowed the laserist to focus on the things that made the show a SHOW. So, meta choreography is one the things Laserium did right.

The 351 data for Laserium '79 has been decoded and reviewed. This show, which I never saw, is stuffed full of great 351 choreography. In some parts rapidly changing values are used to add to the variety of effects achieved with just the minimal gains and offsets scheme.

Attached are a few more photos I have of the encoder. It would have been really fun to learn how to operate these decks. For example, I'm curious how effects where the four color channels are rhythmically chasing each other's sizes were set up.

I thought the CYGN-A thread concluded with some respectful tribute posts to some of the original crew. Those posts seem to have been removed.

I'm currently working on the wiring chart for the Audio Compressor and Amplifier section of the Audio Mod Card.

[laserist]

Those are all pictures of the stuff that made Studio A's encoder the master encoder. John Tilp, then Scott Anderson, and Darryl Davis were the principle choreographers from my time. If Jon Robertson could find the documentation it would be fun to figure out what everything did, but I'm not sure there was a documentation package for those boxes. I never saw one.

[Greg]

Here is a test of the Audio Compressor Amplifier section of the Audio Mod board.

[laserist]

I saw that inconsistentcy in the Audio Mod documentation at some point, but never looked into it. Thanks for cleaning it up.

[TheHermit]

Those are all pictures of the stuff that made Studio A's encoder the master encoder. John Tilp, then Scott Anderson, and Darryl Davis were the principle choreographers from my time. If Jon Robertson could find the documentation it would be fun to figure out what everything did, but I'm not sure there was a documentation package for those boxes. I never saw one.

John Tilp, great laserist with long straight blonde hair. The last time I saw that encoder being used, it was when Randy Resnick was putting together a show in a marquis tent for the launch of Eberhart Schooner's 'Transformation' album in Munich, with a 3 piece 'punk(?)' backing band, who called themselves, "The Police". I was involved in the initial recon and Phil 'the Moose' Gustan was there for the setup. The laser system was in the middle of the king poles, underneath the stage, projecting onto a 20' diameter parabolic screen, flown overhead.
Out of respect, Phil kept calling Ebbie 'Heir Schooner' (ref: "Yavo, Heir Commandant", Sargent Schultz, Hogan's Heroes), but I don't think that it was received by modern Germans as a compliment. "I don't know why Phil calls Ebbie that," said Ebbie's wife.
Thanks for refreshing those memory cells.

Greg- "I'm curious how effects where the four color channels are rhythmically chasing each other's sizes were set up."
Are you referring to the two colormod prisms with a 'beam torquer' scanner? The 1st prism separated the RYGB beams, enough to use knife edge pickoff mirrors to reflect one beam width onto each of the 4 scanners. The second prism stopped those beams from continuing to diverge, making them perfectly parallel. The beam torquer scanner translated the parallel beams across the knife edge pickoff mirrors, effectively changing the colors being reflected onto each XY scanning head.
The angle of incidence on both prisms was critical to the beam torquer's deflection, otherwise the color group wouldn't stay parallel, causing an undesirable colored 'twisted rope' effect.
Not sure if this answers Greg's question, but hope it helps.
I love reminiscing over this stuff.
Hyperspace leap 45 years later:
Having modified 2 of my projectors, I'm building a new control system, using Teensy 3.6 MCUs, with audio DACs for 8 channel QOSCs, doing all the work inside each projector (no FB3/4, nor ED3 DACs). I'm using Teensyduino's audio library with Arduino's IDE. Easy peezy.
The Teensy QOSCs are each independently controllable via usbMIDI, from either Cakewalk's DAW and/or a MIDI control desk. So far all of that's working as a proof of concept, with an Akai APC40 MIDI controller.
But, the parts are on their way for a new custom MIDI laser controller (floating in the back of my mind for decades), using software controllable RGB LED lit pushbutton/rotary encoders (color indicates current 'level'), RGB LED backlit pushbuttons (color indicates bank/status), and an easily programmable, multipage Nextion touch screen to reconfigure all of the controls into banks. It will also be used for slider gains, along with my 17" multitouch computer screen for directly controlling the DAW's channels.
Just thought I'd share what I'm up to with some folks who understand what it's all about.
Best Regards & Happy New Year, Laserheads!

[laserist]

I don't remember who told me the story. It could have been Phil, but short story - Somebody threw a Halloween Costume party, John Tilp just died his hair black and showed up as the only one without a "costume". Nobody recognized him and kept asking who the guy without a costume was...

[Greg]

I'm curious how effects where the four color channels are rhythmically chasing each other's sizes were set up.

Glad you're still here, TheHermit. Yeah, no, nothing to do with the colormod. That subject will come back up when the expansion of Brian's colormod signal to RGB circuit to include 4 RGB channels with fixed color offsets and beam torquer is imminent. I'm talking here specifically about the RYGB gains that are present in the 351 data frame. The visualized 351 for Cars I posted a link to contains effects where, for example, The gains (image sizes) sweep between blue inside green inside yellow inside red, to the opposite, where blue is the biggest and red is the smallest. Obviously this was done using the encoder. It looks too perfect to have been done with four fingers on sliders, though maybe not. Musicians do develop skill. I believe the answer is that that cannot be known at this time, though there is a legend of documentation in the possession of Jon.

Photos show the triangle signal and the 90 degree phase shift at 100 Hz circuits, as well as the direct audio mod effect, which looks as expected. The next steps become more interesting, as little golden obsolete multipliers with kooky networks of trim pots are involved. I'll look back through the threads, as I think multipliers, laser trimming, external resistors, quadrants etc. were previously discussed.

[TheHermit]

I'm talking here specifically about the RYGB gains that are present in the 351 data frame. The visualized 351 for Cars I posted a link to contains effects where, for example, The gains (image sizes) sweep between blue inside green inside yellow inside red, to the opposite, where blue is the biggest and red is the smallest. Obviously this was done using the encoder. It looks too perfect to have been done with four fingers on sliders, though maybe not. Musicians do develop skill. I believe the answer is that that cannot be known at this time, though there is a legend of documentation in the possession of Jon.

Photos show the triangle signal and the 90 degree phase shift at 100 Hz circuits, as well as the direct audio mod effect, which looks as expected. The next steps become more interesting, as little golden obsolete multipliers with kooky networks of trim pots are involved. I'll look back through the threads, as I think multipliers, laser trimming, external resistors, quadrants etc. were previously discussed.

Glad to still be here, all things considered. TBH, I didn't really understand the question from the get-go. RYGB gains? So, instead of solenoid beam shutoff flags, each scanning head had it's own intensity scanner? R= 0 phase, Y=90 phase, G= inverted 0/180 phase, B= 270 phase for colormod, perhaps?
You guys are in way over my head when it comes to old analog electronics. Prior to lasers, I was a tool and die maker for Northrop. So, designing and machining optical systems were my side gig as a laserist. I've designed some panel layouts, but left the electronics engineering to the professionals.
Looks like you and Brian are trying to restore some old salvaged Laser Images gear to a fully functional projector? Sure, why not if you've got all the bits and pieces. That would literally be a monument to the laser entertainment industry, worthy of building a planetarium dome around.
What are the odds for its completion?

[mixedgas]

See attached

Steve

[TheHermit]

See attached

Steve

Yes, that was our London Laserium projector in 1978. Great to see those mechanical drawings, as well as the modular electronics drawings of the waveform generators, mixers, & multipliers. See if you can spot the similarities with my current Teensy modular connections on my latest controller project:

Teensy Laser Controller:

The LFOs can also provide DC offsets and user defined images/waveforms. Some good ideas simply stand the test of time. Or am I just an old laserist at heart, still stuck in the past?