Yeah. It was neat. But it rebooted in under a second so a complete crash was no biggie.

RAM wasn't even cleared so usually no (or limited) data loss.

I thought it was PR#6 (redirect output) to boot from the disk controller in slot 6. I wonder what redirecting input would do.

That was it at the AppleSoft BASIC prompt (or IN#6). But the parent poster commented on how to do it from assembly.

There is an even quicker way from the monitor:

6 CTRL+P

Will instantly divert output to slot 6. (and boot the disk if there is hardware there)

Both worked to start a boot from the disk controller in that slot.