Mr. Backup Z64 FAQ

You must flash a special bios, which enables HDD support like the new 2.20.
The best thing would be installing a small 2,5" hardisk since you then won't need an external powersupply.
Therefore you need an adapter that converts from 3,5" IDE to 2,5"IDE.

The HDD has to be formatted with the FAT or also called FAT16 file system. Each partition mustn't exceed 2,00GB in size. The Z64 can handle 8GB in total so you can have 4 of these 2GB partitions. To format you should use a tool like FDISK on a DOS Boot CD. You can also format within Windows.