https://www.macworld.com/article/152038/logicplatinum5.htmlthis article is dated jan 2003 but the 5.3 update was posted in september / october 2002
http://web.archive.org/web/20021017112938/http://www.emagic.de/english/support/download/update.htmlif you check the download link they only post 5.4 for osx - 5.3 maybe is os9 only?
are you sure there is an osx version of 5.3?
https://www.insanely-great.com/928/0Apple-owned eMagic Releases Logic Platinum 5.3 for OS 9
September 11th 2002
By Mike Flaminio
Emagic has released Logic Plantinum 5.3 for OS 9, which has complete feature parity with the recently-released OS X native version.
Emagic notes the following improvements in the latest version of Logic:
- Enhanced Audio Engine incl. Support of multiple output instrument plug-ins
- Aux Channels
- Additional Audio Engine Features
- Plug-In Enhancements
- Track Mixer Enhancements and Changes
- Track Automation Enhancements
- Score Editor Improvements
- Software Instrument Changes
- EXS24 Enhancements
- Logic Control Changes
- General Improvements and Changes
This is a free update for owners of Logic 5.0, available for immediate download.
Analysis: OS 9 isn't quite dead yet, despite Apple's ownership of eMagic. One reason there are many audio apps (such as BIAS', eMagic's) which will remain as OS 9 versions for some time is because most music pros agree that OS X has lousy audio support to this stage, although Jaguar has taken some steps to ameliorate this. MIDI input is one problem. Another is that many VST plug-ins have not been updated to work in X and will only function when used in OS 9 (for example, in Bias' Peak VST, which is available as a Carbon OS 9/X app. But we can probably expect some killer OS X apps out of Apple-owned eMagic in the future - maybe iMusic?