Mandelbrot Core

[kobus]

All,

Did a Mandelbrot core a couple of months ago as wanted to learn about FPGAs.

Have uploaded it to https://github.com/jacquesdriessen/MiSTer-mandelbrot.

Control with the keyboard (z/x is zoom in / out, and adws to navigate). Rest of it should be self explanatory.

In terms of technical implementation:
- Only a small amount of VHDL (simply to integrate things).
- Most of the logic is done using drawings [found it amazing that you can just "draw what you want"]
- There is one part distributing all the "points to be calculated" over the pipelines.
- Could cram 20 pipelines on the design (you can individually switch the off) that do the actual work.
- And the last part then takes the output of the pipelines and moves it to the frame buffer.

I hope you will enjoy it.

Jacques.

[LamerDeluxe]

Awesome, another classic added to MiSTer and really fascinating to have it implemented in FPGA. Looking forward to trying it.

[aberu]

This is very cool! Thanks!

Now someone do the matrix effect next!

[hiddenbyleaves]

There is a genesis homebrew called Matrix Digital Rain that I boot my MiSTer into instead of the menu core.

[hiddenbyleaves]

Will this display on a crt?

[kobus]

Assume it will not display on a CRT. Using 1920x1080 HDMI Framebuffer.

[AntialiasedPixel]

This is super cool! I keep meaning to do some projects with my DE-10. I got about as far as generating some color gradients on the screen a year ago and haven't had time to tinker with it since.

What limits zooming on fractals? Is it the iterations or a memory thing? I remember using Fractint for DOS on a 386 and being able to zoom in super far. It seems like it's somewhat limited here, but I haven't played around with the settings a ton yet.

[pgimeno]

What limits zooming on fractals? Is it the iterations or a memory thing? I remember using Fractint for DOS on a 386 and being able to zoom in super far. It seems like it's somewhat limited here, but I haven't played around with the settings a ton yet.

The limit is precision. Fractint (which still lives) switches to arbitrary precision numbers at certain zoom levels, but doing the same in hardware is complicated.

[pgimeno]

Checked it now, it works great up to the precision!

Would it be possible to enable screenshots? When I tried to take one, it said "Scaler not compatible".

Also, would it be possible to add flipping of up/down and left/right? I get confused, especially with left/right.

[AntialiasedPixel]

Also, would it be possible to add flipping of up/down and left/right? I get confused, especially with left/right.

I'll second this request, the controls were opposite what I was expecting.

[Moondandy]

That's very cool you did this, there is a Mandelbrot core on the NT Mini Noir. Can this be added into the Main repro in the Other section?

[ericgus09]

I am getting a really bad display with this core anyway to override the resolution settings, doesn't seem to play nice with my DELL LCD monitor (U2410 F Size: 24 in Resolution: 1920 x 1200).. screen is scrambled and jumping all over the place.. no stable picture .. F12 menu works but the graphics are a total fail.

[bazza_12]

screen is scrambled and jumping all over the place.. no stable picture .. F12 menu works but the graphics are a total fail.

same

[Alkadian]

I confirm this behaviour, same here.

[kobus]

Checked it now, it works great up to the precision!

Would it be possible to enable screenshots? When I tried to take one, it said "Scaler not compatible".

Also, would it be possible to add flipping of up/down and left/right? I get confused, especially with left/right.

- Thanks for answering the question on zoom levels.
- Flipping left/right etc. implemented.
- Inability to do screenshots / no VGA output / fixed 1920x1080 resolution unfortunately all have to do with a design choice to use the frame buffer logic included in MiSTer instead of adding a video processor the core. If I understand things correctly the pipeline normally is "core video processor" -> VGA output [also where the screenshot is extracted https://misterfpga.co.uk/take-a-screens ... ster-fpga/) -> scaler for filtering / custom resolutions -> HDMI output. The frame buffer logic needs a (fixed) x / y resolution which is using an alternate path into the scaler [saved having to build a video processor into the core e.g. easier / much less time, but it has it's restrictions. Would be a nice feature to add this but probably take more than the entire rest of the core and wouldn't have time for that in the foreseeable future.

[kobus]

I am getting a really bad display with this core anyway to override the resolution settings, doesn't seem to play nice with my DELL LCD monitor (U2410 F Size: 24 in Resolution: 1920 x 1200).. screen is scrambled and jumping all over the place.. no stable picture .. F12 menu works but the graphics are a total fail.

So sorry to hear that - custom resolutions would be hard to implement (would need a way to pass them on thought the menu and have used all but one "bit" e.g. this wouldn't be sufficient). Only "sure" way I could think of in my other post which would to implement a video processor in HW and then pass the output through MiSTer and all it's magic to deal with all sorts of monitors but no plans / time to implement that.

[Moondandy]

Kobus, do you have any plans to add your core to Main? Am sure Sorg would be good with it going into the "Other" section. Be great to get some more exposure to this and people to get any updates automatically via the update script.

[lazytechnician]

screen is scrambled and jumping all over the place.. no stable picture .. F12 menu works but the graphics are a total fail.

same

Same for me too I'm afraid

[Moondandy]

Tried it on my new monitor, just standard 1080p resolution, and it is jumping all over the place. Could any more information help you problem shoot this? Seems to be a problem for a lot of people.

[Jae099]

I am new to the MiSTer. To install this you just download and install it on the root of your sd card, right?

[Moondandy]

I am new to the MiSTer. To install this you just download and install it on the root of your sd card, right?

Best place to put it would be in /media/fat/Other or make a new one /media/fat/Unstable

Keep in mind the core seems pretty broken, certainly over HDMI, but let us know how you get on.

[Jae099]

I'm using HDMI, so I'll let you know how it goes. Thanks for the info.

[pgimeno]

Best place to put it would be in /media/fat/_Other or make a new one /media/fat/_Unstable

Keep in mind the core seems pretty broken, certainly over HDMI, but let us know how you get on.

Beware of Markdown! I have disabled Markdown in this post to quote you so that the underscores are actually shown instead of activating cursive.

[Jae099]

20250123_153316.jpg (2.92 MiB) Viewed 5560 times

When I load the core this is what happens. And it flashes. Any idea on how to fix this?

Thanks.

[pgimeno]

Have you tried to turn it off and then on again?

Only half-kidding. Old cores suffered from a bug in the framework where changing cores totally messed up the video until the next reboot.

Apart from that, it works fine for me.

[Jae099]

I rebooted the core and tried both versions.

[LamerDeluxe]

Still works here as well, on my 4:3 iPad monitor.

[Jae099]

I have uploaded short videos to show what is happening.

Mandlebrot Zoom 20.12.11
https://imgur.com/etbS6QX

Mandlebrot Zoom 21.05.16
https://imgur.com/qSHTFXS

[remax]

On my Hdmi screen, i fixed it by adding

[mandelbrot]
video_mode=8

in mister.ini

may worth a try

[Jae099]

Do I just add it to the end of the Mister.ini file?