As to the prom reader I'll send it along with the various odds and ends assuming I can find it...
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As to the prom reader I'll send it along with the various odds and ends assuming I can find it...
Greg,
I used the bitbox mainly for debug, but also, it was useful if you wanted to set some spiral or cycloid frequencies that were difficult to find during the show because sometimes the images were not up for very long. With the bitbox you could set up a stable image and play for however long you needed. Also the bitbox was useful when you had something like a commercial rental for an evening and the client wanted a specific type of image on the dome. Remember, without the tape, you had no access to spirals, rotations, DOG stuff, scan-glasses, lumia, and more. (Though you could bring up scan-glasses and lumia with very awkwardly placed switches inside the projector head...). I think Bing (my backup laserist and assistant director of the Morrison Planetarium) and I did program a couple shows with the bitbox too.
Ron
Quote:
Originally Posted by Greg
A Rosetta Stone of sorts has been made available: these two (photo attached) photocopies of the two sides of an unpopulated CYGN-B board. As well, All the difficult to obtain components for the CYGN-B have been obtained, almost all were donated from an original inventory. Tremendous appreciation goes out to the giver. As well, an order for all the commonly available components (precision resistors, tantalum caps, etc.) has arrived, so now the preparations for the building of a CYGN-B is beginning in earnest.
Here's a request for comment regarding raw signal output from such sources as the DOGN that command large instantaneous moves, and it's suitability for delivery (through ILDA port) to, for example, a currently available system from a respected industry leading manufacturer.
The software I use for timeline based choreography applies an "optimization" to the actual points output to the laser. This results in virtually silent scanner operation, and accurate images that look great.
If I disable the optimization, the scanners are noisy.
The manufacturer has an excellent reputation for great scanners, and provides assurance that they are impervious to damage due to rogue signals.
Any thoughts on if it is safe to apply dogloids (signal within electrical spec for ILDA obviously) to such a system, and just ignore the noise?
First observation the dogloids are way slower than the ilda test pattern. Second these things were developed using G-124s. That is to say relatively slow non feedback scanners. You may be disappointed with the dogloids on feedback scanners. The ringing to a stop at each discreet point was a huge part of their charm. The ringing changed as the points move relative to each other, resulting in a more interesting effect as it ran through a cycle. You could emulate the ringing in code, but probably not on a 6502...
Oh, and the CYGNB ran fine on G-120 feedback scanners. Scanners making noise was normal at times with the Mark 6, but usually you couldn't hear them over the music. The first time I heard the scanners doing direct audio mod without the cover of the music was a shock.
Greg,
I neglected to include the scan of the back-side of the CYGN-B card before. Had I known you wanted it, I would have. So... here it is in all its glory. A second Rosetta Stone. Fewer blue-wire mods in some places, and more in others. Enjoy.
Ron
Attachment 56874
Quote:
Originally Posted by Greg
For anyone following along - the wire wrap jumpers were mods made when LIČ replaced their slotted can chopper with a AOM for their Beatles show (btw Sam McGee (who I despise - to this day) convinced the Beatles licensing board to grant us synchronization rights for the first time ever - Beatlemania I was told was a Yoko Ono thing, but if I'm mistaken in this statement Sam did have a severe problem with truth telling, and I find it hard to believe I've just quoted anything he ever said as factual...) those were clock signals from 2 of the three digital oscillators on the CYGNB board. It was a nice effect, but it was really memorable so it was also an "I've seen this before moment" if you used it too much in an hour long planetarium show.
Mixedgas goes to take a Tylenol after seeing a certain name come up... Shudder....
Steve
Brian,
Yes. I believe that Sam was singularly responsible for almost bankrupting Laser Images with that Beatles deal. Took years to pay that off. Poor Ivan kept hiring business people that never actually helped the company survive. Ivan was certainly a visionary we can all agree, just not a business visionary. I don't think we ever recovered from the Sam McGee era. Snake-oil salesman if I ever met one.
The only issue I ever (always?) had with the AOM (and PCAOM) was that it wasted a good portion of the light from the laser (and were super hard to adjust). Our shows were never quite as bright after that. Our current era of individual solid-state lasers has solved that issue. No more PCAOM necessary!!!
Ron
Quote:
Originally Posted by laserist
I have to agree. Neigher of the krypton lasers I had in 2013 were bright enough for an 80 foot dome if I had a pcaom in the light path. And I used a killer Newport 5 axis mount - so alignment wasn't the problem. Maybe something was defective - everything says 10% - I was getting 50% losses - I was literally still tweeking the electronics at 2 in the morning of the first show. When I tried to run through the show for the first time I discovered the someone reduced the gain of the beam torquer so it's only purpose was a tiny amount of color correction - rather than something you could use to perform a freaking show. Luckily I had some resistors in my kit since - again 2 AM. Nobody noticed I didn't have chopper - - - except me... I seriously thought about putting a slotted can galvo chopper back in the system, but I was so burnt out from being a one man show and working full time as well that I just never go around to it before I said, ENOUGH!
It took about a year to get what I call my "offline processing" back after shutting things down. Doing Laserium and working full time simply sucked down all my bandwidth.
Should have mentioned:
Thank you Steve, for providing some scientific papers in which the black magic underlying the design of this circuit is revealed.
A while ago in this thread, dsli_jon posted, and I didn't recognize who it was. I was confused when he mentioned we may have previously spoken, and wrongly concluded it was someone else. Thus, my reply was flippant, and made no sense. Jon and I have recently spoken, and the misunderstanding was resolved.
I have been a bit worried that at some point someone could demand I stop reverse engineering their IP, but after an exchange with Jon, I don't think that will be the case.
Ron, that's super helpful. I was wishing I had a better photo of the back, and there it was!
There is previously unknown lore surfacing in this discussion, and Brian, your technical points, as always, are much appreciated. Thanks for posting, everyone.
I had forgotten about the beam torquer. Now I remember operating that dial. That was my first encounter with the word torque.
I'm glad you got a chance to talk to Jon. I would have been high and dry if he hadn't stepped up.
See pic. (Sad trumpet sound.)
Update: The correct boards have been re-shipped. I'll be back from travels in early September and will resume posts on the building of the CYGN-B at that time.
Home at last. All the parts needed to build the CYGN-B have been mustered. Also, a real unpopulated CYGN-B board has been made available for reference. Also the stereo DACs for the C64 to poduce DOGN signal are here.
Any shipments waiting my invite now have it.
That's the +-15 power supply in back in the photo.
Oscillator 1 of the CYGN-B (photo of build progress attached) should be testing within a week.
Steve, Jon, Ron, Brian, and others following, I hope you are weathering the tumult of the times and the world with sufficient peace in your lives to find interest in the forthcoming fruits of this restoration effort.
Oscillator 1 of the CYGN-B has been assembled on the breadboard. With a variable resistor added between pin 7 and ground, the 555 appears to be functioning as a VCO, and a train of negative going pulses exists on the collector of Q2, which is the line that provides the clock signal, but the shift register and the rest of the circuit doesn't seem to be doing anything interesting. Investigation continues.
I obtained readings from all the pins in the 8 bit shift register. The clock signal is arriving at pin 8 (clock). All the bit output pins are sitting at ground, so the Johnson counter is obviously not functioning. Pin 9 (clear) is also sitting at ground, which is preventing the circuit from operating. Upon lifting clear from ground, the circuit produced the digital sine wave as seen in the photo. This is a good result. One axis of one oscillator of an authentic CYGN-B is generating it's output!
There is no signal present at the cosine and inverted sine outputs, but this I expect will resolve with further trouble shooting.
I do have a request for wisdom however, if anyone still retains a deeper understanding of how this works. The curious little N channel dual gate depletion mode MOSFET that pulls all the clear pins to ground, and had to be lifted for the circuit to work, seems like it is supposed to perform a global clear of the counter under certain conditions, but why, and when?
Next task is to investigate the MOSFET and verify that the leads have been correctly identified.
Wiring error discovered. Photo shows the sine and cosine. Huzzah!
These photos show the AM function of oscillator 1 being tested with a signal from a function generator. One great feature of the CYGN-B is how the oscillators perform all the way down to zero frequency. When the wiper meets the rail, the dot stops where it is. This effect, seen here as some sweeping bars by adding AM to an oscillator tweaked at a very low frequency, was used in the Hendrix number in LaserockII.
Greg,
Great progress! I haven't been looking at PL for a week or so. I'm very impressed with the number of prototyping boards you have arrayed out in front of your oscilloscope. Way beyond what I'd imagine anyone would do. Of course, what you see on your 'scope is not quite what you'll see with scanners. Electron beams don't have the inertia of ballistic scanners!
Great job!
Ron
Quote:
Originally Posted by Greg
Thanks Ron! I'm glad you're still here. I thought of something that would be fun to see posted here if you happen to find one in your archive: a photo of the ringing KQO. That would be the first thing I'd look for if I ever gain access to more of the documentation that has been so generously provided by contributors. The image rotator is another thing that would go really well with a working CYGN-B.
I have concluded testing of the Oscillaror1 of the CYGN-B. It is fully functional, but a mystery remains. The entire circuit involving the SD305 MOSFET, a resistor, a capacitor, a signal line from the counter, and the clear line of the counter, appears to be superfluous. The oscillator runs fine with this part of the circuit removed, but can't function with it, as the MOSFET simply holds the clear pins low, which is a perpetual clear. I can guess the purpose is to initialize the counter with a clear on power up, after which the MOSFET is supposed to function in some sort of monostable way, and keep the connection between the clear pins and ground open. It doesn't want to work this way though, so I'm leaving it out of the current build.
Interesting updates on the CYGN-B may take some time to appear, because the next phase of the project involves documenting and hard wiring this oscillator, and a duplicate for oscillator 3, before building the more complex oscillator 2 with it's famously useless triangle wave output (though that effect was great in the introduction to Turn Me On by The Tubes.)
More good news on another front: I expected the quest for stereo DAC output on the C64 to be a high hurdle, but the DigiMAX seems likely to do the trick, as I have plugged in sample code from MadModders available here:
https://www.youtube.com/watch?reload=9&v=GZsFehLtsqU
and the first run produced a great result: Wiggled first one channel, then repeatedly wiggled the other channel. This means that viewing the dogloids on an oscilloscope may not be far away.
Normally I'd use Eproms or SIn/Cos in analog for that. But the CYGN waveform looks so good when modulated that I just ordered a bunch of shift registers and precision resistors.. Here we go... Mine will use similar building blocks but will not be a CYGN-B. We loves us our Laserium., So I will be honored to have that distinct waveform. I went back and read that article I sent you, mines a 24 instead of 36 point, but no depletion MOSFET. Folks who use old style DMs regularly tell me they can be sloppy on tolerances due to the problems with the older P channel process used.
Cheers Greg!
Steve
Since this was pre-ilda, what did Laserium use as a test pattern to tune scanners to?
Steve
Steve,
Brian, please correct me if I'm mis-remembering things. When we started with our open-loop scanners, we had a special card that we plugged into the card cage somewhere (???) and it put out a 4-point square image. We tuned our home-built amps to get *just* the right ringing of the scanners at the corners of the square. Wait... Let me look into the Mark IV documentation I have here... Nope. I have schematics, but no alignment procedures. I'm barely remembering some pre-programmed pre-ILDA test pattern that we used for aligning our in-house closed-loop scan-amps, but it's been too long (It's been over 20 years (!!!) since I performed Laserium shows.) That test pattern may be on some video tape I digitized for our Laserium archive, but it would take a long time to find. If I run across it, I'll post it.
Ron
Quote:
Originally Posted by mixedgas
Ok, so two flip-flop walking ring counter to make the quad square. I've done that before. I figured one of the keys to the beautiful images was ringing on the open loop. I have a pile of open loop scanners and I know how to add the damping. So basically an General Scanning A106 amplifier with just servo, offset, and damping,. No wonder modern galvos have that "too perfect" look on consoles. Thank you for letting me know.
For those of you going" say what" older galvos have a torsion bar to return the shaft to the center position, and it can add all sorts of ringing and harmonics to an image. Modern galvos don't need it, the position sensor and servo loop forms a virtual spring.
So now I just need to figure out the joystick and offset, and how the splits to the four scan heads worked. I have an idea of how to do it with op-amps.
What do you call it when the 4 colors go off from center in symmetry with the same image ??? It is my favorite effect.. Its what got me interested in like 1986 or so. It led to a career. Pink Floyd's song Sheep, with a still frame of a 8 bit sheep outline, going from an overlapped white sheep, out to one up, one down, one left, one right, translating out from center, and spinning, on the way. Of course with one in red, one in green, one in blue, one in yellow on Lumia. That one and Blue Danube.. Between Buhl and Bradenton, lasers on weekends and lasers on vacation got me hooked...
"Get a "B" average or better in your Junior Year, I'll get you the HENE".. Love, Dad..
Steve
There was an alignment board that plugged into the multiplier summer position that had 8 toggle switches to insert a square wave at the 4 x/y outputs. The damping was adjusted to center the ringing of the square wave. The CYGN-B wasn't really all that influenced by damping. The dogloids were where the damping (or lack of damping) would really show an effect.Quote:
Originally Posted by ronhip
Laserium had fixed rotation option for each color that was done with op-amp "networks". Variable rotation done with 4 quadrant multipliers.Quote:
Originally Posted by mixedgas
I think you're talking about swept spirals... or just swept offsets.
Here's a dogloid. (photo)
To do: Fully test and tidy the code, hack the digimax to get DC output and possibly separate the four DAC outputs so at least two of the four DOGN channels may be enjoyed at the same time.
I will have to begin linking to videos of this output, as this is doing a manner of clever motions that need to be seen.
Getting DC from the DigiMAX only required shorting two caps. These photos show examples the DOGN output, including the dogloid which I previously speculated involved a ramp waveform (It doesn't.) As Brian predicted, these are a bit disappointing, even seen here on the beautiful Tektronix 604A. I have a request in to a local university for the return of my Catweazle, from which I'll produce a catalog of each DOG patch, and my 594 HeNe will be happy to finally get a chance to do something useful.
The freaky thing is I can imagine the next step in most of those images. Admittedly I sat and watched the last show (for at least!) 5 nights a week for 4 years before I did my first Laserium show.
Thanks!
Greg,
Looks like you've made great progress! From what I see on your sillyscope, you've got it working beautifully! You're giving me Laserium flashbacks!
I had never heard the term "Catweasle", however, and had to do a search. I still don't really understand how an obscure medieval British sitcom relates to medieval Laserium imagery.
Ron
Quote:
Originally Posted by Greg
It relates through Karn Evil 9, not really. I see what you mean, it's not obvious through a search that catweazle refers to galvos by MediaLas:
http://www.laserist.org/Laserist/Tech_focus_p4.html
Photos show the dogloids tested with G100 scanners, an audio amp, and the unmodified DigiMAX (no DC.)
DC test coming next.
You have a yellow HeNe? Rare! I have one at the Exploratorium that I put into an exhibit.
Ron
Quote:
Originally Posted by Greg
I just think it's cool that if you get far enough from 575nm digital cameras will stop seeing green...
Here are some photos of more Laserium Flashbacks from the DOGN. Providing DC to the audio amp input to drive the G100's works but only for little DC. Conveniently, converting 0 to 5VDC DAC output into -+10V control voltage is a very common thing to do, and VREF is available on one of the pins of the DigiMAX C64 8 bit stereo DAC. And I have the Catweazle back (Thank you Michael of The Photon League), so a video catalog of DOGN output with laser is coming.
Four of the 16 dogloid patches are a waving conductor's baton effect that kind of looks like a light saber or a drum stick, and is very recognizable from the old shows. One photo here imperfectly shows this.
Go ahead and ridicule my inefficient use of breadboard. Here are oscillators 1 and 3 of the CYGN-B prior to the permanent build. One axis of each oscillator is output to the sillyscope. Notice that the lissajous is rock stable. This proves that the legend of the syncing 555's is true. Investigating this unique feature of the CYGN-B is something I have wanted to do for a long time.
Here's an update photo of the CYGN-B build. Oscillator 2 is in progress. The oscilloscope photos each show two oscillators. The signal is taken from one of the output "bits" of that oscillator's Johnson counter. One photo shows illegal states, which sometimes occur on power up. The other photo shows the same signals after use of the counter reset button I added. The schematic shows the reset circuit which replaces the MOSFET part of the circuit.
I remember reading the book "A Yaqui Way of Knowledge" years ago. One episode which stuck with me was, in my interpretation, a cautionary tale directed toward givers of gifts. The narrator takes it upon himself to seek out a sorcerer whom Don Juan had mentioned. On finding and meeting the person, the narrator name drops Don Juan, and the sorcerer gives the narrator a gift of rare plants, and cryptic instructions regarding their care. Unfortunately, the narrator is not the accomplished sorcerer he was mistaken for, and the gift is wasted and lost. The takeaway being, make sure the person to whom one gives a gift actually recognizes the full scope of what is being given.
It's a drag, but I have to travel again. Fortunately, an entirely unexpected shipment arrived today. Two days later and I would have missed it. There is much to present and discuss regarding what was sent. The item of immediate use which I am thrilled to receive is the (see photo) plate of metal from a V!b panel in which the CYGN-B controls get mounted.
Something of great potential significance that was also graciously sent to me, is a collection of four un-populated printed circuit boards that are obviously modules of the mark 6 or perhaps the mark 4. Of course I would very much like to know which modules these boards are. I'll post photos once I get where I'm going, and we'll see if anyone has some educated guesses to throw.
I have photographed the newly sent materials, put most of it in a bank vault awaiting my return, and packed up the CYGN-B to take with me, as I expect to be able to complete the build while I'm away.
An update regarding the DOGN: This project is basically complete now, except for porting the DOGN algorithms to the cyc emulator. See the photo for the three small pieces of hardware needed. One is the SD card reader that replaces the 1541 disk drive. All that is on the card is a less than 2K file containing the assembled code. Another item seen in the photo is the DigiMAX stereo DAC. The third is an easy to build set of two potentiometers (paddles) which connect to game port 1. This setup requires only the C64 keyboard and power supply, SD reader, DAC, and dials box. In other words, the monitor and disk drive do not need to be set up in order for the DOGN code to load and run.
I have set up the Catweazle galvos and obtained video footage of all the DOGN effects and patches, and also a demonstration of using the pots to offset the frequencies of the dogloid oscillators. This footage will become available as a short documentary on the DOGN Which I will edit and post while I am away.
Ron, would you care to describe the exhibit in which your yellow HeNe is being used? I remember in the 1970's, the Ontario Science Center had two HeNe (red) lasers used in exhibits, apart from their world class laser demonstration. None of this now exists. One was a demonstration of audio transmitted by modulation of the light, and the other was showing the internal reflections of a laser beam in a glass rod, representing an optical fiber.
I apologize, but there's still stuff to come... including a thumb drive that will ID the boards - most of Laserium's boards were 44 pin Vector wire wrap boards, I'll be sending some of those too. What you do (or don't) is up to you... ;-)
Greg,
The exhibit I mentioned is basically a laser demonstration table. Sorry, I don't seem to have a photo right now. Maybe after the pandemic. On this table, and protected under a plastic cover, we have RGB laser diodes, and the yellow HeNe. The beams come out parallel and separated by about 6" and travel across the length of the table about 1" above the tabletop. We keep them down low on the table to increase safety. All beams are 5mW or below. We have various optical devices (mirrors, lenses, cylindrical light pipes, shower-glass, diffraction gratings, and much more) that our "Explainers" (what we call our student docents) can use to demonstrate principles of light. We also have an ultrasonic mister they can use to reveal the beams. It's all pretty basic, but you get the idea.
Ron
Quote:
Originally Posted by Greg
Here is the link to the dogloids catalog video:
https://youtu.be/fJ7kAR7D8yU
Attached photos show oscillator 2 of the CYGN-B now working. That means all three oscillators are now done except for the minor bug seen in the photo. The discontinuity in the sine wave shows a wiring error involving the rows of resistors.
I'm away from home for a while, and the only oscilloscope I could scrounge up doesn't have xy mode. I did stuff a 2W RGB system into my back pack though, so I should be able to document the operation of the CYGN-B with that and post the results. There was only one staff screening carry on, and that person seemed to be completely unfamiliar with the sight of bags of resistors, a soldering iron, a guitar capo, the CYGN-B, etc. But the thing that most flustered the person was simply a gimbal mount. Kept asking WHAT is this?
Brian, I'm super psyched with the possibility of seeing and testing specimens of the wire wrap vintage technology. As mentioned though, I'm not at home to receive shipments, so please contact me for arrangements prior to sending anything.
The DOGN board could never have run as fast as your video does at times. Its timing was based upon a 555 timer generating a reset signal. At some point the reset stepped on the image algorithm and that's all she wrote until you turned down the speed control.Quote:
Originally Posted by Greg
That is interesting. I wondered what the 555 was for. It also explains why the entry point to the code in the documentation is labeled RESET.
Here is a repost of information provided previously by Brian regarding the CYGNB panel controls:
The CYGNB was built around a 44 pin Vector form factor (4.50" x 6.50" x 0.062"). Some of the early boards were wire-wrapped - and were geek Artwork. It used 10K - 10 turn pots for frequency. There was a 10V reference on the board for the frequency pots. The gain/symmetry used Allen Bradley triple coax modpots dual 10k for X&Y and a single 20K for symmetry. The symmetry worked by exposing the X or Y summing junction to ground. The AM & FM gain each used 10K dual coax modpots. Polarity was done with EAO switches. The master Gain was a 10K dual pot. All the pots were linear. (end quote)
Attached photo shows the Allen Bradley coax modpots. I've figured out how to mix and match these to get what is needed. I'm short a 20K, but I can work around that.
Something I'd like to know is if the other side of the frequency control pot receiving the 10V reference voltage connects to ground, connects to the wiper, or is not connected.
First, I've been looking at old hardware to send out and I may have been wrong about the am/fm pot either I've got a bunch of stuff for something else or the am was 10k the fm was 100k.Quote:
Originally Posted by Greg
Second, the 10k - 10 turn frequency pots had ground and 10 volts across the pot and the wiper went to the input of the VCO.
Ok, that's great info, thanks Brian. I'll keep that in mind when testing the build which is nearing completion. If you do decide to send materials, please contact me for an address update so nothing irreplaceable gets misplaced.
Ron: in case you want to send me your board at some point and have me repair it and send it back to you, I'd be happy to do so. I doubt there is anything on that board I couldn't diagnose and fix, and the legacy inventory I'm currently holding has spare parts.
Oh, I've got some odds and ends lying around that I'm never going to use for lasers since my design philosophy has evolved a bit over the years, but it can wait until you get home. At the moment I want to build up a box that will take The Radiator's ILDA output and insert Laserium style Color Mod I, II, and chopper. The Radiators #9 preset has something like a Laserium color mod using a LFO, so you can do gain (somewhat), but the gain has visible steps & isn't remotely as responsive as I'd like. I've thought about buying a MIDI surface, but - old school... Next step, four output channels with master x/y gain, individual gains, variable rotation, fixed rotation, and joysticks with damping and overrides. We'll see how it goes from there.Quote:
Originally Posted by Greg
i took a look at preset #9.. I don't if by "gain" you mean intensity or something else, but LFO1 and LFO2 are sending some data to the intensity channel and that may make it less responsive than what you're expecting. If you unroute those signals, it might be smoother for you.Quote:
Originally Posted by laserist