[rescue] Sun 3, Sunos 4, 3/60 Boot Block ?

[Chris Quayle]

Hi,

I've been trying to build a new system disk for an old
Sun 3/60 system.

Around 1993, built a disk enclosure with 2 x 766 ESDI fh
drives and 60 meg magtape + interface boards to convert
to scsi. It was my first desktop Sun system, used for
a number of years until upgrading to Sparc. Pulled it
out a couple of years ago, all ok other than a flaky
psu. Tried it again this year, but root sd0a is US.

Have dump files for the root, usr and home partitions,
so formatted another drive in a Sparc LX, also running
SunOs and restored the partitions from backup. Have
searched all the usual places, but can't find any
reference to install the boot block, or whether this
needs to be done before or after restoring the root
partition ?. Have tapes., but no working tape drive and
would be better to have the machine back as it was.
Assume dd may be relevant, or, there is an
installboot command on the LX, but not clear how to
use it it this instance, though it should perhaps
work if given the right Sun3 boot file

Any ideas ?...

Regards,

Chris