fork from https://framagit.org/3hg/isotop
Install OpenBSD. See intructions.
Download isotop last archive and checksum.
$ ftp https://framagit.org/3hg/isotop/raw/master/isotop-latest.tgz
$ ftp https://framagit.org/3hg/isotop/raw/master/isotop-latest.sha256
$ sha256 -C isotop-latest.sha256 isotop-latest.tgz
If OK, extract archive and run scripts :
$ tar xvzf isotop-latest.tgz
$ sh isotop-user.sh
$ su root isotop-root.sh
When you have finished, feel free to remove every isotop-* files.