Microprocessor controls and EMD’s new 710G engine first appeared together in SD60 demonstrators EMD 1 through 4 between May and June 1984. Years later, the prototypes were still testing new technologies out on the road. Witness SD60 No. EMD 3 on the lead of a Burlington Northern Santa Fe coal train at East Dutch, Wyoming, on June 14, 1997, now riding on a set HTCR-II radial trucks that will become standard on locomotives starting with the SD60MAC model.