If a message like "It may have been corrupted or tampered with during downloading” occurs when trying to install older versions of Mac OS X, it might be that the installer is too old and the certificate has expired.
To fix this, set the date and time the install is being done to some time a few years in the past (about the time the installer would have been current). Set it using the date command from terminal: date {month}{day}{hour}{minute}{year} (example date 010101002015 for 1 am on 1 Jan 2015) then install again.
I usually write a blog post about once a week. The latest post can be viewed here: Learning from Failure: I think there is a place for parties with views I find insane. (posted 2024-11-28 at 12:41:49). I do podcasts too!. You can listen to my latest podcast, here: OJB's Podcast 2024-08-22 Stirring Up Trouble: Let's just get every view out there and fairly debate them..
TIPS PAGE