The "Unitor" from C-Lab provides SMPTE synchronization (to or from other SMPTE devices), two additional MIDI IN ports (II and III), two additional MIDI OUT ports (E and F) as well as a "Multi-port" for connecting the "Steady Eye" or "Human Touch".	The Notator SL dongle fits in the front of the Unitor-2. On the Unitor-N and Unitor-C, the Notator SL and Creator SL copy-protection electronics are permanently placed inside each unit respectively. The dongle slot connector can be used for any additional dongle-based program or cartridge as it's simply a 'through' extension of the Atari ST cartridge port.