NetBSD/sun3x runs on all Sun3x class machines. These are the models 3/80, 3/460, 3/470 and 3/480. NetBSD runs on other Sun3 machines but they are supported under the NetBSD/sun3 1.3 release.
NetBSD/sun3x 1.3 is no longer the most recent release of NetBSD/sun3x. Subsequent patch releases to 1.3 have fixed this problem. The answer is provided below, however, if you cannot install a patch release.
Due to slight change that was made to the NetBSD kernel before the release of
1.3, the manner in which a specific NetBSD architecture boots itself from an
embedded filesystem is different from previous releases. Unfortunately, we
didn't catch this change in time for the sun3x release. Consequently, the
RAMDISK kernel doesn't automatically find the filesystem within
it. When booted, the kernel will display the following.
device md0 (0x700) not configured
root device (le0):
To proceed make sure that you do not to choose the default device (le0.) Instead, type in md0. Afterwards, you will also be prompted for the dump device and filesystem type. At both of these prompts you must select the defaults (hit enter.) The welcome banner of the RAMDISK install program should then appear, at which point you can continue normally with the instructions from the INSTALL document.
Due to a similar problem which plagued the initial NetBSD/sun3x 1.3 release, the NetBSD/sun3x 1.3.2 RAMDISK kernel doesn't work. To workaround this problem we recommend that you use the RAMDISK kernel from the older, NetBSD 1.3 distribution. It will boot properly and allow you to install the miniroot for the NetBSD 1.3.2 distribution.