12 Oct 2025
A new update to MacSim has just been released:
MacSim now treats breakpoints within a hex file - a hardware breakpoint - as a regular breakpoint that can be enabled and disabled. There is also a preference to disable these breakpoints when the file is loaded.
The position and size of any open inspector window is now saved between launches.
Various interface improvements and minor bug fixes.
9 Sep 2025
I am pleased to announce a new update to MacSim. This version has a completely revamped interface and many bug fixes. It also uses Apple’s new interface frameworks so the minimum OS version to run it is now 10.14. Unfortunatly it is also unsigned which means the first time you run MacSim you will have to approve opening it by visiting the Privacy & Security panel of the System Settings.
20 Mar 2020
Since Rondo won’t work on the latest MacOS ‘Catalina’ and I haven’t sold licenses for a number of years now, I have made a free license available to anybody who would like one.
18 Nov 2016
After a successful run of over 10 years, our MIDI playing app Rondo, has been discontinued. It still works on recent operating systems but is getting really long in the tooth and is proving impossible to update. There are vague plans for a rewrite but it could be a while. Many thanks to all the people that purchased Rondo over the years.
Rondo is still available for download from here.
26 Aug 2015
I am pleased to announce a new update to MacSim. It’s been a long time coming and it nearly didn’t happen, so I thought I’d explain what went wrong.