Internal Magnetic Media342 iSeries HandbookAlternate Installation Device support allows you to perform installation and recoveryprocedures using a combination of devices. Prior to V4R1, these types of activities could onlybe performed using devices attached to the first system bus. The first system bus connects tothe service processor IOP. Typically this is where the optical device or tape devices used forinstallations are attached. On OS/400 V4 systems, you can use a combination of devices thatare attached on the first system bus and on additional buses. The alternate installation deviceis not attached to the first system bus.On the Model 270 and Model 8xx V4R5 systems, the Alternate IPL device is attached to anI/O adapter that is controlled by the base IOP in the system.If you use the alternate installation function, the system uses existing support (a device onthe first system bus) to install or recover enough of the Licensed Internal Code required toperform an IPL with an IPL-type D. When using the alternate installation device support, thesystem continues the operation using media in the alternate installation device. This functionsupports installation and recovery from tape media, such as SAVSYS tapes or distributiontapes that you created, which contain Licensed Internal Code and may contain the operatingsystem, licensed programs, and data.See theBackup and Recovery Manual , SC41-5304, for more information.Tape Unit Descriptions4 GB ¼-Inch Internal Cartridge Tape Unit TechnologyThis tape may be used for save/restore, Alternate IPL, program distribution, migration, and¼-inch cartridge tape exchange. Backward read/write capability to previous generations ofQIC drives protects the customers investment in QIC technology.This tape is not compatible with System/36 tape units. For read and write compatibility, referto internal tape read/write compatibilities table on page 339.13 GB ¼-Inch Internal Cartridge Tape Unit Technology (Supported but notorderable)The 13 GB tape unit provides 16 GB capacity native and 32 GB capacity compressed with adata transfer rate of 1.5 MB/s (native) and 3 MB/s (with compression) using a 1500-footcartridge tape. The #6485 also provides 13 GB capacity native and 26 GB capacityAn Alternate IPL device must be attached to an IOA adapter card that is controlled by thebase IOP in the system. Any other tape drive can be an Alternate Installation Device.Important