MFM Drive? Use a RLL-Controller, DEBUG G=C800:6 an gain about 40% space on the same harddisk. OK, the defect map does not match anymore, but no risk, no fun :-D

did you check this program? http://www.z-dbackup.de/download.html it is in german, but has great functions. There is a freeware-version that makes backups up to 4 GB. The professional versions starts at 25€ (~ 30$). Greetings from Germany Andreas