You can use the pmagic-4.0.iso from the pmagic-4.0.iso.zip or pmagic-grub4dos-4.0.iso.zip archive. The pmagic-4.0.iso from the pmagic-4.0.iso.zip archive uses isolinux as bootloader, the pmagic-4.0.iso from the pmagic-grub4dos-4.0.iso.zip archive uses grub4dos as bootloader.
When you want to use grub4dos iso emulation without adding extra parameters to the Parted Magic kernel, you can only put the iso only in a few locations, namely /, /images/ and /pmagic/ else Parted Magic won't find the iso which is needed to access the rest of the files.
Grub4dos can use 2 distinct types of mapping: direct and memory mapping: