Atlas N 40005115 DCC Sound Missouri Pacific MP #321B FB-1 Diesel Locomotive August 17, 2026 By 0 At the height of cab units, this was ALCOs foray into the market. Over 600 were built from 1946 to 1956 with 400 of them being FA units. DCC equipped. Dual mode DC and DCC operation. Supports all DCC programming modes.