How can I download a MacBinary Archive file to my Mac mini 2020

I can't imagine why you would want to transfer the contents of a MacBinary file to a camera.

MacBinary is a format that people invented way back in the early Mac days, to be able to take a Macintosh file that contained both a data fork and a resource fork, and encode it into a flat file that would survive a trip through a non-Mac system, This, and other similar text-based formats, were the only way to safely distribute shareware, as in the pre-Mac-OS-X days, application code and many application resources resided in resource forks.

Camera vendors sometimes do distribute camera firmware updates in the form of binary files that they want you to put onto a memory card and transfer to the camera. These binary files are in some format that has meaning to the camera (but generally not to the computer that is used as a vehicle to get them to the camera).

Are you sure that this isn't simply a case of the Mac assuming that because a file has a .bin extension (or something like that), it must be a MacBinary file (even though it isn't)? .bin, like .dat, is a very generic extension and there are a lot of different programs that have used that extension for files that have very different structure and contents.

What is the model of your Nikon and what is this "MacBinary File" supposed to contain?

FWIW, if you are downloading any file that is not directly from Nikon meant for the camera, you are taking chances that can introduce something on to your Mac system or alter you camera in a way to brick it.

Never ever download anything from any source other than the vendor of the product it is meant for, i.e. if it is a Nikon product only download from Nikon. While many sources may seem trustworthy, it is not uncommon for them to get uploaded files that have been compromised.

"Keka" is now my preferred archive tool. I used to use The Unarchiver but I seem to recall several years ago there was something critical about it. Maybe because it appears to now be associated with MacPaw (see the bottom of The Unarchiver web page), also tied to CleanMyMac which definitely gets a bad rap on these forums.

See if “The Unarchiver” can open it.

The file you are trying to download sounds like it has been stored in a "package". You can't use this package directly. You have to unpack the package on your computer to get to the file it contains. To do that you need a tool on your computer that does that. We have provided the names of two of them, for both of which you can do a quick web search and find the developers' web sites, or you can download them from the Mac App Store. I wrote a bit more about each app here --> What is the best winrar alternative for m… - Apple Community

Frankly I have never heard of a file being transferred to a camera. You provide no information about this file. Conceivably it could be a firmware update but then you need to know how to use it. I do have a digital camera but there are no files I can transfer to my camera. You may wish to get additional advice before you proceed with all this since it may involve a level of understanding that goes beyond simply not knowing how to unpack an archive file.

Have got link to that file & have you tried just copying it to your flash card, like…

1. Using a card reader, copy “******.bin” to a memory card that has been formatted in the camera.
2. Note: Be sure to copy the firmware to the root (top-most) directory of the memory card. The camera will not recognize the new firmware if it is placed in a folder under the root directory.
3. Insert the memory card into Slot 1 on the camera and turn the camera on.
4. Select [Firmware version] in the [SETUP MENU] and follow the on-screen instructions to complete the firmware update.
5. Once the update is complete, turn the camera off and remove the memory card.
6. Confirm that the firmware has been updated to the new version.

Is it really a very old MacBinary file? Or just a firmware update .bin as described by BDAqua? I suspect it is the latter.

Anyway, you could inspect it with:

macbinary probe -v file.bin
"file.bin" is a MacBinary-II file.

Or try to decode it with:

macbinary decode -v file.bin
macbinary: "2025-0615-1745-53.heic" created.

Limnos wrote:

Frankly I have never heard of a file being transferred to a camera.

Some digital cameras can save their settings to the camera's memory card and/or to a connected computer or flash drive; conversely those same setup files can be loaded onto the camera. For example in my case, I have two Nikon DSLRs that I wanted set up identically without having to go through all the individual settings manually on both cameras. So I set up one of the DLSRs, saved the settings to the camera's CF card, swapped the CF card into the second camera and loaded all the settings into it in a single step. I also saved a copy of the settings file on my Mac as a backup copy.

Firmware updates are usually loaded onto the camera by copying the update file to the camera's memory card and installing the update via the camera's menus.