Sun3 machines usually need little or no preparation before installing
OpenBSD, other than the usual, well advised precaution of BACKING UP
ALL DATA on any attached storage devices.

You will need to know the SCSI target ID of the drive on which you
will install OpenBSD.  Note that SunOS/sun3 uses confusing names for
the SCSI devices: target 1 is sd2, target 2 is sd4, etc.

It might be a good time to run the diagnostics on your Sun3.  First,
attach a terminal to the "ttya" serial port, then set the "Diag/Norm"
switch to the Diagnostic position, and power-on the machine.  The
Diag. switch setting forces console interaction to occur on ttya.

The console location (ttya, ttyb, or keyboard/display) is controlled
by address 0x1F in the EEPROM, which you can examine and change in
the PROM monitor by entering "q1f" followed by a numeric value (or
just a '.' if you don't want to change it).  Console values are:
	00: default graphics display
	10: tty a (9600-N-8-1)
	11: tty b (1200-N-8-1)
	20: Color option board on P4

OpenBSD will use the EEPROM setting to determine which device to
use as the console, so you should make sure it is correct.