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- Nov 28, 2007
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- Your Mac's Specs
- Silver M1 iMac 512/16/8/8 macOS 11.6
If you clone the internal drive to an external, using say Carbon Copy Cloner or SuperDuper it will be bootable meaning you can start up from it, choosing it in System Preferences > Startup Disk under Users & Groups. As I said boot from that, go to Disk Utility, choose the internal drive and erase.