Changes
Loaders
,/* Cassette */
=== Cassette ===
Loading from cassette effectively uses all the CPU's time because you have to keep checking it must poll the cassette signal input in order to see if it has changed, convert the sound into data.So to do music and you use a CPU other things during loading requires precise timing loop to calculate length of signal.
I think only Firebird games had loading music on cassette. The music was composed by Melvyn Wright ([http://www.melright.com www.melright.com]). The music data was embeded into the data on cassette. The data was read as a group of 3 bits and 8 data bits. The 3 bits determined if the 8 data bits were for data or for music.