How do I create a MySQL slave server of a bunch of MyISAM databases on a master
Can you shutdown the master server long enough to copy the data folder to another location?

You don't have to perform a mysqldump. You could just shutdown MySQL on the master server and copy the 'data' folder (folder having your database files) to another location (or server). Next, start both servers with replication disabled (skip-slave-start). Next, issue a RESET MASTER and RESET SLAVE on both servers. Then do a CHANGE MASTER on the slave. Finally, start the slave. If you are using GTIDs, then remove the auto.cnf file on the SLAVE so that it generates a new UUID (auto.conf is usually stored in the data folder).

See this for step-by-step instructions: http://mysql-vsjr.blogspot.com/2015/09/how-to-clone-gtid-mysql-56-server-using.html