Doepfer CTM64 Contact to Midi Interface (main board) - Manual (Page 16)

Another pin header labelled JP8 is located right to the main processor. The jumper installed to JP8 has
this meaning:
Normal / Toggle operation
• Jumper installed in upper position (GND, towards the XTAL): normal mode (factory setting)
• Jumper installed in lower position (+5V) toggle mode
When the toggle mode is selected the CTM64 transmits alternately note on and note off at each closing
of the contact (opening the contact has no meaning in this mode). This can be used to realize a toggle
switch e.g. in Ableton Live).
Control Change mode
When two resistors are installed to JP8 instead of a jumper the control change mode can be selected.
In this mode the CTM64 transmits Midi control change messages instead of note or program change
messages. The resistors work as a voltage divider and generate certain voltages that are used by the
CTM64 firmware to select the control change mode:
• 10KOhm from center pin to GND / 20kOhm from center pin to +5V: Control change mode normal
• 10KOhm from center pin to +5V / 20kOhm from center pin to GND: Control change mode toggle
For the control change messages the same parameters as for the note messages are taken (i.e. the
note number corresponds to the control change number).
Remark: The state of JP8 is checked only once during power on. It is not possible to change the
operation modes defined by JP8 during operation !