Arpanet for ARM Macs

After upgrading to VCV 2.5.2 I had painfully to learn that Arpanet, a meticulous recreation of the beloved ARPSequencer and definitely my sequencer of choice, isn’t available for ARM Macs - as are all modules by Fehler Fabrik.

As the Fehler Fabrik web site hasn’t been updated for years I fear that Ross Cameron has left the VCV community, hopefully not for tragic reasons.

Being a complete computer idiot myself I now can only hope that somebody here is able and willing to adapt the Arpanet code for ARM Macs.

Any chance?

Kind regards,


It seems to be in the works.

and a binary build for Mac Arm64 here:

you may have to make a free github user account to download it.

Dear Jens Peter Nielsen,

thanks for your fast and - as far as I understand it - uplifting reply.

However, as said before I’m a complete and total computer idiot. (Also I’m an old fart.) Therefore I have some questions troubling me:

Do the github links you provided allow the hope that any time soon the Arpanet module will be available for download by ARM Macs at the VCV Library page, i. e. will the red marker “not macOS ARM64” disappear at that page?

Or will I have to unzip the zip file (which I was able to download) to the path “/Rack/plugins-mac-arm64/ directory” (which the search function of my Mac can’t find)? If so, will the Arpanet be recognized by the VCV app as well as by my patches like any other module?

With the hope not to misuse your kindness and

kind regards,

Wieland Samolak

What happens when you click on “open user folder” ?


Dear Peter Vos,

thanks for your advice!

I indeed located the folder and moved the unzipped folder “FehlerFabrik-Suite” there, but unfortunately opening VCV after that resulted in two times this error message:

'“plugin.dylib” can’t be opened because Apple cannot check it for malicious software. This software needs to be updated. Contact the developer for more information."

Any idea?

Kind regards,

Wieland Samolak

I’m not a mac guy but I think it’s something build into the MacOS that prevents people like you to enjoy your software :wink:

Maybe someone with a mac will come along and tell you how to circumvent the issue. :smiley:

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No Mac here either, but I have built the plugin on the official toolchain - it should have the proper signature.

Here’s a Mac Arm64 build you can test.

(link valid only for 10 days - I don’t intend to take over this plugin)

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Dear Jens Peter Nielsen,


As you might have guessed from my first sentence, it worked. Thank you very much!

And also a Thank You to Peter Vos who showed me how to place such a plugin.

Being the old fart and computer idiot that I am I now have one concern: Will the code which I just downloaded survive future updates of VCV?

Also, wouldn’t it be nice to make the code official, so that the nasty “not macOS ARM64” in the Library disappears and anybody with an ARM Mac has access to this beautiful module?

Kind regards,

Wieland Samolak


Not guaranteed. But as long as the source code is available, It almost certain that someone will make it work in future versions (often outside the library). Only VCV can issue a guarantee - you have to ask at VCV - Support

regarding making the fix official: The developer has stated that he doesn’t have the time now to update his plugin*. VCV usually does not take over the development of a 3rd party plugin to make them work in newer vcvrack releases - no matter how minor the change may seem to be.

see Plugin Licensing - VCV Rack Manual

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Thanks for the enlightenment!

yes, this is true. If a plugin/module is totally abandoned by the original developer it rarely makes it back into the library. I know if two ways:

  1. The original developer explicitly gives someone else permission to take over they module(s), and someone does this. That happened when I abandoned my 28 Squinky Labs modules and they were taken over by @robert.kock . I don’t know if there are other examples.

  2. If the original plugin license allows it, a different developer could make new module based on the source code, but would usually have to make a new panel and/or new branding for it. This also rarely happens, although it is permitted by most licenses.

Sometimes the original developer can be persuaded to “bless” a fix, and through the work of others the original author re-submits the now ported code to the VCV library. This happens sometimes.


Pgatt and I took over mschack also

There’s 5 open source modules in the library which are not ported to arm. One has the source removed from GitHub. One has the above pr which would fix it. The other three have prs from me. The authors have not merged these prs so it is safe to assume the modules are permanently abandoned

Lars has a thread here somewhere with the list of non arm modules. Edit: here Modules with ARM builds! - #73 by LarsBjerregaard

I suppose an intrepid developer could set up a github fork of those, merge the pr, add the github actions, and make a build available ourside the library.


well, sure, people do that all the time. But I think OP explicitly wanted something in the library. And that is not a path there, of course.


The prs I added to the modules upped the version and linked to the library issue! Literally two clicks and it’s done. The authors I think have either abandoned the project or ignored the github notifications.

Ahh well. Sometimes software just ends.


Hi guys,

looking again at this thread I was astounded that the discussion has continued. Before I write my probably most redundant reply I once more have to point out (and thereby starting the redundancy) that I’m an old guy with some experience in modular synthesis but not the slightest idea on how computer programming works.

This is my understanding of the topic:

Fehler Fabrik (Ross Cameron) hasn’t updated his modules, especially the beloved Arpanet for some years. Therefore they are incompatible with ARM Macs.

In his first reply Jens Peter Nielsen writes “It seems to be in the works.” while the links he provides rather suggest to me that it isn’t. (Most probably my lack of understanding.)

The “FehlerFabrik 2.0.2 Mac-ARM64 Build” linked in Jens Peter Nielsen’s reply doesn’t work (at least on my ARM Mac).

After Peter Vos thankfully taught me how to do so I was able to to place a working plugin within VCV which Jens Peter Nielsen even more thankfully programmed - as it seems exclusively for me because he provides the download only for a limited time and says he has no intention to make it official.

Also he confirms my suspicion that this exclusive plugin might not survive future updates of VCV and suggests to contact the VCV Support via E-Mail, which I of course did. The reply was: “We don’t tend to adopt plugins that have stopped being updated, but perhaps someone in the VCV Community might be able to with the developer’s permission.”

So my - probably naive - question is: Which technical, legal, and/or ethical reasons hinder if not Jens Peter Nielsen himself then another person of competence to implant Jens Peter Nielsen’s existing plugin to the Fehler Fabrik modules so that they stay accessible for any interested person in the VCV Library?

Should the reasons be legal, and/or ethical, would it be possible to re-label the modules and publish them again? (I remember to have encountered several modules in the VCV Library that were described as “inspired by” or “modified from” other modules.)

Getting REALLY impudent I’d like to point out that Arpanet, like its historical model, suffers from two structural shortcomings:

Each step of the Sequencer can have the logical function ON, OFF, SKIP, or RESET. Unfortunately there are only three Gate Busses. So a fourth Gate Bus would be extremely desirable. Not to compromise the original layout an individual Gate Out jack for each step would be equally effective.

The efficiency of the Arpanet/ARPSequencer would grow dramatically if the Sequential/Random toggle had a logical input (On = Random).

Maybe on the occasion of re-labeling the module a gifted person could cure these shortcomings…

@Squinky: I really love your modules, especially the EV3 for its compact efficiency and its GORGEOUS normalized sum output. If only there were CV inputs for the levels of the three sources of that output…

But I guess I better shut my mouth now before I get expelled from this forum.

Kind regards,

Wieland Samolak

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Well Wieland, you’re right and it’s all a bit of a mess regarding abandoned plugins. We had a “war” here a couple of years ago, going from one extreme to the other on this subject. Sadly, nothing got resolved into a sensible and practical “adoption policy”. The barriers are 1) Sometimes a license on artwork in a plugin, which means replacing that, that’s the minor bit, and 2) The “VCV ethical guidelines” about what can be submitted to the library.

I don’t think many folks here have an appetite for reviving that debate, or believe that Andrew will change his mind on it. So there it is…

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Made a FR let’s see what happens ? :smiley:

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Hi folks,

My lack of activity with the VCV community over the last few years is indeed the result of tragic circumstances - I’m no longer someone who writes code for fun, I now write code for a living. If that wasn’t bad enough, what spare time I do have has been taken up in the pursuit of a degree. Suffice to say, if I did have a desire to write code for it’s own sake, I don’t have the capability.

That being said I would like to allow as many people as possible to enjoy the work I’ve done in the past. cwmoriarty on GitHub has very kindly removed a dependency that was preventing the plugin from building on ARM. The main reasons I haven’t approved their pull request is that I don’t currently have a personal machine set up for development/music work, so I haven’t been able to build their version myself to review it. I’ll try and get a dev environment spun up tonight so that I can move forward with this.

As for further features, I’m not really interested in adding anything to ARPANET that wasn’t present on the original machine.

If anyone wants to fork my work for whatever reason, I have no objections. My only ask is that they not use the Fehler Fabrik name or logo, nor the specific panel designs I’ve created. That is to say, if you want to release your own versions to the public, please use your own name and artwork.

I’m of course very pleased to hear that people are using and enjoying the modules. While I don’t have time to do much work of my own, I’m always happy to listen to what people have been making with my code.

Thanks, Ross


Despite all the posts, and despite @LarsBjerregaard 's residual bad feelings, this topic is very simple, and what I posted before is accurate, and has not been contradicted by anyone. The issues are clear, mostly laid out in the original license of plugins, and VCV does have a clearly stated policy about this.

I see that the author of these modules has taken a small step to option #1, but is still saying that in order for someone to redistribute the module in question, someone is required to do whatever changes are necessary to remove the original branding. This is not unreasonable, imao, but does require some work for someone.

When I “abandoned” the Squinky Lab modules, I explicitly gave one developer permission to re-distribute them as is, with the original branding. I send emails explicitly allowing that to both @robert.kock and to VCV. There was no problem, other than that @robert.kock still needed to host the code in github, do the porting work, modify some links and such, and re-submit the plugins.

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You can use uMAP to CV control a switch. Click MAP on uMAP, then click the switch. A magenta square is added to indicate the mapping. (Input 0V to uMAP = Sequential, Input 10V = Random).

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