Okay, in that case you can autoboot a disk by mounting the image:
OPEN15,8,15,"CD:diskimage.D64":CLOSE15
(or @CD:diskimage.D64 if you have JiffyDOS)
then typing BOOT
LOAD"...",8 is the same as DLOAD"... so that should be okay.
If you were using LOAD"...",8,1 that could cause the out of...