Quick Hints 2 February 2025 - Running QMC2 for the first time / older MAME installs
Hint #1: Prior to running QMC2 for the first time, please ensure that your MAME install is up and running, i.e. passes the Gatekeeper. This restriction also applies to Intel Macs with modern MacOS systems installed. Without this, the QMC2 setup will not recognize QMC2 as an installed MAME application.
This applies to the MAME executable and the SDL2 Framework, which after each upgrade must again be manually authorized in the Privacy & Security section of the System Configuration.
If you hate this (like I do) -> go for the Homebrew/MacPorts install of MAME, as described in my dedicated post, and no Gatekeeper woes will infest your MAME updates. Further details on QMC2 are mostly still valid from my old post of 2016 on QMC2.
Hint #2: Scanning the ROM directory first time is very buggy in QMC2 and often results in crashes. Don't worry, just restart the app, choose the option "Once" and the scan ends. Be sure not to do any multitasking during this scan.
Hint #3: Older MAME installs - start from scratch: When you move to a newer MAME version after a longer time, the second tip I have is to start a new mame install by renaming the $HOME/Application Support/mame directory containing the old ini files. For example MAME 278 introduced new audio latency options that can make problems with old mame.ini files. So if you are stuck with launching MAME and end up in a blank screen, I recommend that you restart with a new mame.ini file. This should resolve most of the MAME black screens at program launch.
Update 23 December 2025 - First fully notarized QMC2 MacOS Binaries online
I finally managed to create MacOS app bundles (both ARM64/Silicon and Intel) that have been notarized by Apple. For this to succeed, I had to bundle the SDL2 Framework into the app bundle and codesign everything with hardened runtime.
Grab it here: https://github.com/estefan3112/qmc2-mame-fe-MacOS/releases/tag/v244v4
Both App versions should work flawlessly - but please look into the ReadMe file if unsure.
Update 6 May 2024 - GitHub Fork with MacOS Binaries
For easier deployment, I created a fork of the QMC2 Github Repository here:
https://github.com/estefan3112/qmc2-mame-fe-MacOS
You'll find here latest pre-compiled and code-signed versions of QMC2 for both Apple Silicon and Intel Macs. You'll also find Shell scripts for compiling the Upstream source code and self-sign the app. Right now only for Apple Silicon, soon for Intel Macs as well.
Question: I downloaded the QMC2 app, but MacOS tells me that the file is corrupted. I already tried right mouse + open at least twice, but with no success.
Answer: Sorry to hear, your QMC2 app might be in the quarantine. To lift the quarantine, please execute this command in the Terminal
xattr -cr /Applications/qmc2-sdlmame.app (please adjust the path to your QMC2.app, if required)
Enjoy.
Update March 2024 - in (far too late) Memory of Rene Reucher
Only these days, far too late, I learnt that Rene Reucher, the creator of the QMC2 frontend, passed away in spring 2023. Back in 2022, when I wrote the first version of this post, Rene has restarted his work on this quite unique MAME frontend, and it was a pleasure for me to help him out on some minor things in relation to Macs, albeit nothing crucial. From two phone calls, I remember him as a very reasonable and pleasant person. This is my very late "Sorry, and all the best, Rene."
As always, please care for the instructions in the ReadMe and do report any problems back, many thanks.
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| I started MAME with the help of QMC2, and it is still a classic frontend experience |
Original post in the following (no longer relevant and rather outdated, as it builds nicely now with Homebrew):
