Testing CDROM with PC Doctor

[James007]

I am endeavouring to test my T22 CDROM with PC Doctor.

Loading PC Doctor by way of floppies admits of the program starting immediately - with no break to allow the Fn+F4 function to swap from the floppy drive to the CDROM drive - the subject of the test. The Fn+F4 works OK normally.

The PC Doctor program seems to override the swap function and I get the usual computer objection noise. How do I test the CDROM?