If you are running AmigaOS, you can use the HDToolBox program to adjust your native partitions prior to installation. Atari partition IDs are three ASCII characters, use LNX for data and SWP for swap partitions. If using the low memory installation method, a small Minix partition is also needed (about 2 MB), for which the partition ID is MNX. Failure to set the appropriate partition IDs not only prevents the Debian installation process from recognizing the partitions, but also results in TOS attempting to use the Linux partitions, which confuses the hard disk driver and renders the whole disk inaccessible. There are a multitude of third party partitioning tools available (the Atari harddisk utility doesn't permit changing the partition ID); this manual cannot give detailed descriptions for all of them. The following description covers SCSITool (from Hard+Soft GmBH). Start SCSITool and select the disk you want to partition (Disk menu, item select). From the Partition menu, select either New to add new partitions or change the existing partition sizes, or Change to change one specific partition. Unless you have already created partitions with the right sizes and only want to change the partition ID, New is probably the best choice. For the New choice, select existing in the dialog box prompting the initial settings. The next window shows a list of existing partitions which you can adjust using the scroll buttons, or by clicking in the bar graphs. The first column in the partition list is the partition type; just click on the text field to edit it. When you are finished changing partition settings, save the changes by leaving the window with the OK button. For the Change option, select the partition to change in the selection list, and select other systems in the dialog box. The next window lists detailed information about the location of this partition, and lets you change the partition ID. Save changes by leaving the window with the OK button. Write down the Linux names for each of the partitions you created or changed for use with Linux — see . Quit SCSITool using the Quit item from the File menu. The computer will reboot to make sure the changed partition table is used by TOS. If you changed any TOS/GEM partitions, they will be invalidated and have to be reinitialized (we told you to back up everything on the disk, didn't we?). There is a partitioning tool for Linux/m68k called atari-fdisk in the installation system, but for now we recommend you partition your disk using a TOS partition editor or some disk tool. If your partition editor doesn't have an option to edit the partition type, you can do this crucial step at a later stage (from the booted temporary install RAMdisk). SCSITool is only one of the partition editors we know of which supports selection of arbitrary partition types. There may be others; select the tool that suits your needs. Partitioning tools for Macintosh tested include pdisk, HD SC Setup 7.3.5 (Apple), HDT 1.8 (FWB), SilverLining (LaCie), and DiskTool (Tim Endres, GPL). Full versions are required for HDT and SilverLining. The Apple tool requires a patch in order to recognize third-party disks (a description on how to patch HD SC Setup using ResEdit can be found at ). For IDE based Macs, you need to use Apple Drive Setup to create empty space for the Linux partitions, and complete the partitioning under Linux, or use the MacOS version of pdisk available for download from Alsoft.