We have a tar utility which you can use to create a standard tar format backup under AMOS, which you can then restore using the standard tar utility included with UNIX and LINUX. (Windows does not come with a tar tape utility, but there are third-party tar utilities available for purchase. One that we have used successfully is WinTar - see their web site at
http://www.spiralcomm.com)
I am not aware of a UNIX, LINUX or Windows utility which can read tapes made with MTUSAV under AMOS. But if you find one, please let us know.