Laser growing up

[laserist]

This is 'The Ghost in the Machine' for Laserium. It's a drawing for a 351 Encoder that was used to do choreography for Laserium shows.

[lasermaster1977]

This is 'The Ghost in the Machine' for Laserium. It's a drawing for a 351 Encoder that was used to do choreography for Laserium shows.

Thanks for sharing that. It was leading edge automation for the time and very inventive.

[Greg]

That gives some insight on what these consoles did (I'm assuming these photos are related.)

Interesting to note that there is a Dog Freq. The effect of this parameter is being documented in a video along with the results of the restored DOGN code I am currently editing.

The 351 data for Laserock2 has actually been preserved, although not decoded yet. Attached is .zip file containing a .wav file that is a short excerpt of this data. Much gratitude to the party with the rare equipment and expertise who rescued this signal from imprisonment in an obsolete format. A couple of other critically relevant releases have surfaced here on PL thanks to the same: a description of the structure of the signal, necessary for decoding, and (Thanks Ron) some documentation regarding the assignment and use of the decoded 351 values. I think it would be interesting to identify and visualize as much of this original choreography as possible.

Anyone happen to know what the big volumes in the photo next to the encoder contain?

[laserist]

That gives some insight on what these consoles did (I'm assuming these photos are related.)

Interesting to note that there is a Dog Freq. The effect of this parameter is being documented in a video along with the results of the restored DOGN code I am currently editing.

The 351 data for Laserock2 has actually been preserved, although not decoded yet. Attached is .zip file containing a .wav file that is a short excerpt of this data. Much gratitude to the party with the rare equipment and expertise who rescued this signal from imprisonment in an obsolete format. A couple of other critically relevant releases have surfaced here on PL thanks to the same: a description of the structure of the signal, necessary for decoding, and (Thanks Ron) some documentation regarding the assignment and use of the decoded 351 values. I think it would be interesting to identify and visualize as much of this original choreography as possible.

Anyone happen to know what the big volumes in the photo next to the encoder contain?

Schematics if I'm any judge. I've seen the schematics for the add on box for the master encoder, but I don't have them. I think mostly they were just notch filters that could do a spiral reset or whatever...

I wrote a visual basic program that would read a wave file of the 352 data, decode, and write it to an access database with a time stamp - you know delusions of doing something clever someday...

[Greg]

You did!? That's the hard part. Do you still have that project? I've done a fair bit of VBA programming.

[laserist]

You did!? That's the hard part. Do you still have that project? I've done a fair bit of VBA programming.

It really not that hard. It's about the timing between the zero crossings. I'm pretty sure I've got it somewhere.

[lasermaster1977]

It really not that hard. It's about the timing between the zero crossings. I'm pretty sure I've got it somewhere.

Wouldn't it be easier to build a hardware decoder?

[laserist]

Wouldn't it be easier to build a hardware decoder?

If I was trying to do classic Laserium I'd just build up a 352 board and the ancillary ADMX and DMUX boards. That wouldn't be very helpful going forward as the dual one-shots the 352 board was designed around are obsolete. Today a micro-controller could do the decoding and even the low pass filtering for the Analog signals.

The first step in my experiment in 2013 with Laserium was to digitize the old analog tapes. They had been sitting in a warehouse for a generation. There's a thing called sticky shed syndrome, and all of the 3M tapes had terminal cases. The oxide wasn't attached anymore. (I know about the oven technique, thanks...) Luckily there was one copy on Maxell tape that was okay. The reason to decode the data on a PC and stick the result in a database was I was worried about data dropouts. Having it all in a database would allow me to develop code to fix the problem or even just clean it up manually. Then write it back as a wave file.

[laserist]

Thanks for sharing that. It was leading edge automation for the time and very inventive.

Nobody does shows like Laserium anymore, and it's not my intention to demean what's being done today. But in case somebody comes along with the energy and drive to do something closer to Laserium, I'm trying to layout enough information so they have a something to go on. Laserium did have a look of its own, and some of what made that look unique involved design concepts that you need to think in terms of four scan pairs to realize the utility. Fixed rotation for example...

[lasermaster1977]

Nobody does shows like Laserium anymore, and it's not my intention to demean what's being done today. But in case somebody comes along with the energy and drive to do something closer to Laserium, I'm trying to layout enough information so they have a something to go on. Laserium did have a look of its own, and some of what made that look unique involved design concepts that you need to think in terms of four scan pairs to realize the utility. Fixed rotation for example...

Time marches on, things change, which is good and sorrowful to some extent, but there was no better illusionary back drop for a 45-50 minute laser show than a planetarium with a start ball, any planetarium any star ball. I applaud your rational for wanting to fully document what Laserium achieved. I, too, have always preferred and found huge value in RYGB pairs of scanners, be they open-loop or closed-loop for presentations. But now RGB 30K pairs would still be terrific. Fixed rotation is the one biggy, the one thing I always wanted to do like Laserium but never figured out a practical way to do it back then, and I lacked the math skills to help.

the dual one-shots the 352 board was designed around are obsolete.

There is always the ubiquitous 556 dual timer/one-shot...

I've done a small amount of VB programming, but not recently. I'm impressed with the idea of using VB code to read and decode WAV data. Anything I can do to help, let me know.

I here you on the sticky tape syndrome. All my 1/4" show tapes were stored in my house for decades. Tracks 1 & 3 were music 2 & 4 XY waveforms. I'd digitized tracks 1 & 3 and 2 & 4 to WAV files. 2 & 4 that contained my laser XY analog signals about 10 years ago or so, all stored tails-out. Depending on the tape formula the sticking was worse and I had to very, very slowly re-wind the tape to the supply reel. I just need to phase-shift track 2 or 4 a tiny bit to restore XY phasing and planned on doing this with my Goldwave app but never got-a-roundtoit.