The T678 was Czechoslovakia's first main line freight diesel design and dates back to 1961. There was also a passenger version, classed T679 and also introduced in 1961. The surviving locos, now classed 775 and 776 respectively, went to Slovakia at partition with the last examples working from Zvolen until the mid 1990s. Preserved T678.0012 made a rare return to the Czech Republic in June 2006. It was photographed descending through the woods west of Revnicov with a Praha to Rakovnik special on 24 June 2006.