Is There a Key Combination That Will Perform a Soft Reboot During Startup?

No. Other than the long press on the power button, the Apple firmware startup doesn’t have an analog to the Ctrl+Alt+Del reset.

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If it’s the startup, try this: Option (⌥) or Alt: Start up to Startup Manager, which allows you to choose other available startup disks or volumes. If your Mac is using a firmware password, you're prompted to enter the password.

yurisend wrote:

Should've mentioned: I'm using a 2020 iMac 27".

Thank you.

Either way, it's not that I'm having difficulty selecting a startup disc, I was just trying to find out if there was a more efficient way of rebooting the computer during startup as I'm very much used to having to do it on PCs.

If you are booting up from off, holding the Alt (option) key will take you to the Startup Manager.

see > https://support.apple.com/guide/mac-help/change-your-mac-startup-disk-mchlp1034/mac

(beware this article got messy when the Silicone process was added)

I suppose it's a small point.

It's been Alt (option) for as long as I can remember.

Thanks.

You're welcome.

OK, I've faced this; here is what I found works. Maybe not supposed to be this way but it works for me. You have to be quick.

Hands off the keyboard; start the Mac. Then quickly press the proper key or keys before you hear the chime. Easy for an Option key start, not so much for an NVRAM reset.

Go to Apple > System Preferences > Startup Disk > choose the Startup Disk that you want and click Restart.

Shouldn't matter, but you never mentioned what year model iMac or what macOSs version(s) you are booting.

I was a windows user for decades; exactly what difference are you speaking of? For both, you press the power button and shortly a login screen will appear. Is yours different?

Apples have no Lock Screen like Windows does, but that can be bypassed. If that's done, the boot processes are essentially the same. Apple has a progress bar; Windows a spinner but those are only a cosmetic progress display choice.

There are startup manipulations you can do that are specific to the platforms, but that's built into the OS and inherent with you choice to use one or the other. Windows has its quirks too such as using the F12 key to get to a startup selection menu or Esc or F2 to enter the CMOS setup. F12 is much like a Mac's Option key start to select startup disk.

You may press different keys, but the processes themselves are very similar.

Why are you forcing a shutdown with the power button?

If you want to boot a different drive while the Mac is up and running, go to Apple > System Preferences > Startup Disk > choose the Startup Disk that you want and click Restart like I said earlier.

den.thed wrote:

Why are you forcing a shutdown with the power button?

Because…

I often boot from external sources (live USBs and such), and many times there are snags during boot which require me to go through the whole *hold power button to shut down, turn comp back on and boot into macos, restart again and select boot device* procedure.

This three-fingered salute is a (potential) way to de-tangle a failed bootstrap, whether an issue with the operating system being loaded or with the medium or the drive.

I’d still expect the hard-halt long-press on power, as I’d assume there’d be debris left from the failed boot.

Good point and I humbly except the flogging.

I guess my problem on this one is/was, that I never had much problem booting OS X or macOS from external drives and never owned a PC.