Apple · Desktop
iMac 27-inch 2020
A2115 · iMac20,1 · iMac20,2 · iMac 27 2020
OptionHold
Startup Manager / boot disk menuHold immediately after pressing power, then choose an available startup disk.
Command-RHold
macOS RecoveryHold immediately after pressing power to start from the built-in recovery system.
DHold
Apple DiagnosticsUse Option-D if local diagnostics does not start.
Option-Command-P-RHold
Reset NVRAM / PRAMApplies to Intel Macs, not Apple silicon Macs.
Manufacturer verified · checked
Intel Macs use startup key combinations rather than a PC-style BIOS setup key.