Just to recap:
Downloaded install66.fs from
https://cdn.openbsd.org/pub/OpenBSD/6.6/amd64/
Per jggimi check she hash with sha256 - matches
dd if=install66.fs of=/dev/sd1 bs=1m
Boot from installation media; choose Shell
ls /dev/rsd* returns "No such file or directory
sysctl.disknames shows sd0, rd0, sd1
dd if=/dev/urandom if=/dev/rsd0c bs=1m returns write failed file system is full.
disklabel sd0 returns "DIOCGDINFO: Inappropriate ioctl for device
disklabel sd1 returns "/dev/rsd1: No such file or directory"
At this point I am in way over my head. My sincere thanks and appreciation to:
Head_on_a_Stick
jggimi
shep
TronDD
for taking the time to try helping me out with this.
Right now I think I'll leave it for a day and then try again. If it still doesn't
work I guess I'll have to forget about encryption and just install the OS.
Thanks again to everyone.