1977-12-20 /AP-4172F-BM/01/3a-documentation/ddt.tco 1977-12-20 /BB-H138A-BM/01/3a-documentation/ddt.tco 1977-12-20 /bb-d868a-bm/01/3-documentation/ddt.tco 1977-12-20 /bb-d868b-bm_tops20_v3a_2020_dist/01/3a-documentation/ddt.tco 1982-12-22 /BB-4172H-BM/01/4-1-documentation/ddt.tco 1982-12-22 /bb-d868e-bm_tops20_v41_2020_dist_1of2/01/4-1-documentation/ddt.tco