I've been asking the same question on 68KMLA and we haven't found a solution.
I'm trying to connect a G3 PDQ to a PB100 thru Target Mode.
On the PB100 end, all is good. I've got the proper connectors etc
On the G3 PDQ end, the problem I have is that the G3 wants to boot from SCSI whatever I do.
Hitting "D" does not help (does nothing)
A lot of documentation about open firmware and keys to hold during boot time is incorrect on the internet.
This is an old world mac, I can enter open firwamre ( ctrl/opt/O/F) but the command "multi-boot" does not exist.
Holding "D" doesn't seem to exist
There seems to be no way to prevent a G3 to boot from SCSI if you ever connect it to a SCSI drive, which makes no sense to me...
Any help/advice appreciated.