IBM 8" Disks - What are they?

Amongst the things which I saved from the skip I have 4 IBM 8" floppies, the labels say: MAP ENTRY DISKETTE **M.T.=5412** P/N=4410338 E.C.=571989 DIAGN.DISK. 1 -------------------------------------------------------- CONTENTS, 0D0-FFB-FFF-FD6-143-FC0,DD6,D44, FC2,DD9,C17-FA0,FA6,FA7 -------------------------------------------------------- STAND ALONE DISKETTE **M.T.=5412** P/N=4247991 E.C.=571931 DIAGN.DISK. 2 -------------------------------------------------------- CONTENTS, LDR-FC0,LD5-FA0,E0A -------------------------------------------------------- 3340 MICRO DIAGNOSTIC DISKETTE **M.T.=5412** P/N=4247992 E.C.=571989 DIAGN.DISK. 3 -------------------------------------------------------- CONTENTS, C16-FA1-FA2-FA3-FA4-FA5 -------------------------------------------------------- 3340 DIAGNOSTIC DISKETTE **M.T.=5412** P/N=4247993 E.C.=571931 DIAGN.DISK. 4 -------------------------------------------------------- CONTENTS, C11,C12,C14,C15,C17-FA0,C18,C19, C1A,C1B,C1F -------------------------------------------------------- Can anyone tell me what these are and what they were for? I realise that they were for diagnostics of some sort and assume that the **M.T.=5412** is probably a machine type, but I am not familiar with IBM's designation numbers. At the bottom of the label is what I assume is a date in the format 77/01/05 - if my assumption is correct then these must be 30 years old. -- Regards Pete