How to: use MacsBug

How to use MacsBug even if you are not a developer?

MacsBug 6.6.3 (499 KB), MacsBug is Apple's assembly-level 680x0 and PowerPC debugger for Mac OS. It can be used to debug code running in most execution environments, from applications to drivers, and everything in between. It's often used as a bug-reporting tool by many 3rd-party developers, as well as Mac OS system software developers. This is the latest version and works on all Macs released until summer 2000 (including Cube). The reference and debugging guide is here (pdf, 1.4 MB). Homepage.

This is a very useful tool not only for programmers but also for normal users. I used it too. I try out lots of software (freeware), and my computer used to freeze (requiring the forced restart, 3 button restart) quite frequently. After installing MacsBug, i was able to identify the source of my problems, and after deleting the software, everything is running smoothly.

A short note on how to use MacsBug: After installing MacsBug properly, you will see the sign 'Debugger installed' during startup. When any problem arises, the MacsBug gets activated, and you will be in a command-line interface (very different from MacOS, quite shocking when i first saw it). You must remember a few commands before installing this: 'rs' (without the quotation marks) to restart the computer after MacsBug is activated.

If you have data that you really need to save, you can try typing 'es' or exit to shell where you exit the MacsBug command line interface, and go back to MacOS desktop. If you do this, either the application at fault shuts down, and all else goes on as usual (where you can then proceed to save your data) or the whole computer freezes (requiring a 3 button restart).

If you are trying out new software, you might want to generate a standard log by typing 'stdlog'. This will generate a lot of details about your computer and the cause of the problem on a text file on the desktop.

Those with iMacs will find MacsBug convenient because you can type 'rs' to restart the computer, and there is no need to look for a paper clip everytime it freezes. Again with MacOS X, the OS freezing will be a thing of the past!