_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

https://youtu.be/zeil5cf4Oto

Neil

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

Terry Jones - Monty Python's Flying Circus.

Neil

For sure!

Once I get through the 2 year long video series on it being made, I plan to focus the rest of my days on making music videos for the channel.
This is the last electronics project I will probably do, so it's fitting that it is my most complex and most useful (for me anyhow).

In the early 80's I owned a real Moog but found it limiting due to single track and no ability (or gear) to make multi track songs.
In the 90's I used Amiga trackers but didn't really enjoy the focus on surgically plugging in notes and I absolutely refuse to learn to read music.

Soon I will finally have me dream station... a high focus on live recording, analog filters from digital waves, and 12 full tracks plus a speech synth track!
The fact that it will be 100% powered by stuff you can find in a VIC-20 just makes it all the better.

Good days coming.

Had another day out in the shack and managed to get the frame for the base completed.
There is a lot of final welding and grinding to do, but the frame skeleton is mostly complete.
If winter continues to hold off, I might be able to complete the speaker area framework as well.

The frame will have two removable pillars that include pull out floppy storage drawers.
Hidden caster wheels will jack up from the underside to allow moving the unit.

The two sections of the stand...



Here is the basic frame ready to rock the back 40...



I came very close to the original concept model...



As for the giant circuit board, I have managed to get some video displayed and a keyboard matrix decoder working.
6502 assembly is the best!

Later,
Radical Brad

That's really starting to come together, Brad!

Neil

Thanks!

It feels a lot more real now that the frame is together.
I am going to keep doing the finishing welds as long as the snow holds off.
Once it snows here, my shack out back will be inaccessible as it is down a long trail at the base of a steep hill.

When that day comes, the frame will move to my basement and I will put the keyboard in, hook up a few breadboards, pull up a bench and jam out for a while to keep my enthusiasm level high. I tend to get bored easy, so hearing some sound come out of the synth during the build will help.

Over the winter I will work on the huge hand wired circuit, 6502 code, source the glass and wood, and start a storyboard for the release of the initial video series in late 2025.

I also have a boatload of retro Commodore gear to sell (including 2 mint Super PETs and 8 VIC-20 units in the original box), so it will be a busy time in the nerd cave this year.

The Synth frame is now welded enough to move indoors for the winter. I made a subframe for the 12" CRT as well and need to make one more small part although it will be a very complex part due to extreme accuracy.

The CRT frame is fastened to the front wood panel with the bezel acting as a clamp. Four bolts integrated in the bezel pull the CRT frame as well as the CRT up against the panel and the inside edge of the bezel, which will be accurately fit to the curvature of the CRT glass.

This is somewhat similar to a Commodore PET CRT bezel although mine will be made of metal. I don't have a model of the bezel as I am now winging it in a race against the snow which should have been here a month ago. Here is how it will look once installed...



I have also made a lot of progress on the Channel and OS code, which is all 6502 assembly. I can now read data from the 1541 drive used for this project, load basic samples into one channel, and play some basic music. Composite video is also being generated at 640 x 224 and it looks great. It is so easy to run out of breadboards space in a hurry!...



Hard to fathom that what is shown above is only one half of one channel. There are 16 of these!!

Next steps will be to hand cut the VIC-20 keyboard opening in the frame and finalize the design of the channel hardware.
This will happen over the deep freeze.

As soon as the beast moves indoors, I will make a few videos of it cranking out some sound.
Later!

Radical Brad

That is an _impressive_ amount of breadboard!

I wonder about the steepness of the keyboard; it looks like an awkward wrist angle might be involved.

Neil

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

Thanks.

That breadboard represents the number of ICs on just one of the 16 channels, and that doesn't include the analog portion.
The video circuit is also about the same size as well.
So what you see in that photo is about 1/32 of what I will be hand wiring.

I chose the 45 degree keyboard install for several reasons.
First, because I need a unit as compact as possible as it has to fit a 70 inch wide by 24 inch footprint.
Second, the keyboard is only for song name loading and saving, so not used all that much.
The function keys will be used the most, so they are on a convenient place above the piano board.

I think of it more like the keyboard on a CNC machine rather than a computer.

Ps...
I see the comments might have been regarding the piano keyboard and not the user console keyboard?
If so, then the photos are misleading due to camera angle. The piano is 100% horizontal as it should be.


Brad

Thanks for the clarification, Brad: I of course was referring to the keyboard[0], as opposed to the keyboard[1].

Neil

[0] alphanumeric
[1] piano

It sounds like BDD was thinking the piano keyboard was at an angle. I guess the angle of the render did look that way.
Here are a few more shots of the unit. The model has been updated to match what I actually built (backwards methods, I know!)







Notice how challenging that CRT bezel is goin to be!
I found some 1.5 inch angle iron and will try to make it tomorrow.
The angle grinder is going to need a lot of finesse to hack out that curvature so it mates with absolute precision.

If all goes well tomorrow, this is what I will have...

Today went well on the CRT bezel design. Even managed to make a frame for the CRT and circuit board.
My CRT is a new in the box old stock Omnivision black and white 12" CNC monitor, and it is great.
I even have a second new CRT in case this one expires before I do.

When I went out at noon, I realized I had no angle iron to work with (needed 1.5 inch minimum).
Disappointed, I started cleaning up for the winter and found an old rusty bed frame. Perfect!...



A few cuts and some flap disc cleanup, and I was making the bezel frame...



Whadda ya know, it is exactly what I had envisioned yesterday...



The curvature was hacked out a bit at a time using my usual high precision method...



Not sure why, but this was very easy to do!
It didn't even need to be this close as I will be installing a rubber edge when I can find one to fit.
This is one solid bezel...



The day went so well that I also made the CRT rear support frame.
This holds the tube, PCB and clamps between the front board...



At this point I am going to find some cheap plywood to just rough in the wood paneling.
That way, I can work on the internals indoors over the winter using the frame to hold everything.

When I do the final metal work, I will probably regrind the curve so the CRT points down a bit.
Since I will be looking up at it somewhat, a slight angle might be better.
There is still almost 1.5 inches of meat to work with, so easy to do.

On last eye candy shot.
640x224 framebuffer (all 7400 logic) loaded up by a 6502...



Still need to tune the CRT a bit to get rid of the visible retrace lines and slight convergence.
Pixel clock is 12.5 Mhz, which does a nice job of filling the screen horizontally.

Of course, this is not the official name of the synthesizer, that is secret for now!

I will reveal the final name on my site by the end of the year... http://www.chopzone.com

Later,
Radical Brad