Your Roland FD-8 controller it should work, also the E-pro Pearl pedal ( but i'm not 100% sure)
Roland It uses a rectangular FSR resistor, so is variable continuos signal that MD can read.
The input jack is the first on top left, visible from back
download/file.php?id=2836Try for factory defaults, boot MD with right button pressed or with AutoloadConf set to 'no'.
If you have multimeter , set around 100-200k oHm and test the TRS cable and your pedal by checking the resistance variations