Disc capacity (16 bit words) 256/sector, 3072/track, 12, 288/cylinder, 1, 253, 376/surface, 2, 506, 752/disc; two discs/drive unit (1 fixed, 1 removable); operating power requirements 120 vac plus or minus 10 percent, 60 hz plus or minus 1 hz; 10.5 in. H, 19 in w, 29.7 in d; 157 pounds; 19 in rack mounting