What is the ruling on printing the Holy Quran on cassette tapes and compact discs, what is the degree of its sanctity, and is it permissible to swear by the Mushaf recorded on them?

Cassette tapes and CDs on which the Holy Quran is recorded do not have the ruling of a Mushaf. As for recording the Quran in the manner mentioned, there is no harm in it, as long as it does not compromise the Quran.