Just executing the ATA3.driver command won't just make it work you also need a CD Filesystem setup with the dosdriver pointing to allegrocdfs which should be in L: or other cdfilesystem and also pointing to the correct unit number for the CD drive.
If you are using the CD2 DosDriver from the fastata package it should be pointing to the secondary master device and to use L:allegrocdfs for the CD filesystem so you need to make sure allegrocdfs is in L.
