Emax

it's a service or diagnostics disk?

Ok

I found it.

M.U.S.T. DISK
The M.U.S.T. disk (Max Universal Sound Test Disk) is provided to facilitate easier and more
thorough functional tests and troubleshooting. The disk contains various presets, which have
Emax parameter set-ups programmed into them. When used in conjunction with the
Functional Test Procedure, the M.U.S.T. disk provides a very complete test of Emax
functions. We recommend that you play other disks (such as the Piano) in addition to the
M.U.S.T. disk after performing your functional test in order to make certain that the unit is
problem free.
Note: It is a good idea to keep your M.U.S.T. disk updated with the most recent version of software so that you
won't have to worry about software problems while doing your functional test.