LTC Module can be used to add Midi-thru port to Midibox, to Midi input/output activity LEDs or to connect Midibox to Computer RS232 port used as Midi a interface.
An easier way to connect to a COMM port would be to follow the “MIDIbox-to-COM” instructions, except using an RS232 Shifter Kit or the pre-assembled SMD version, RS232 Shifter SMD from SparkFun Electronics instead of the MAX232.