System/74

Does anyone have any info on the IBM System/74? I can't really get much access to it because it's gathering dust in a supply room. Also, I have a bunch of data tapes for reel to reel recorders. They are labelled: ADES v.4.0 1600bpi Bad Tape Nova Eclipse ADES 3.0 1600 bpi (labelled bad) 1/4 micro linewidth control patterns, Bell Labs; RDOS dumps of 1/4 micro patterns Tape 0008 Pattern file 2 (A) Tape 0009 Pattern file 3 3/14/91 Tape 0010 Pattern file 4(C-I) Tape 0012 Pattern file 6(L-R) ADES TAPE Advanced Diagnostic Executive System 800 bpi Rev.3.0 7/16/86 5130 Cuchiving Disk (a large list of nonsense follows) 4/1/86 800 bpi DAYDUMP A (I) DAYDUMP A (II) FORTH.FL C-NOVA CONTROLLER Rev. F Any idea what this stuff is, and for what machine(s)?