Farfisa compact MIDI retrofit Installation manual
Vitalii KulakovMIDI kit for Farfisa Compact (CC23 versions without percussion) Like on this photo
Installation:
Board installed under switchboard. For this, sometimes you may need to cut the springs a little bit to make free space between the MIDI board and switches in the installation area. Skip this step if distance between board and springs is good, or some insulation like blue paper tape. 
2. Drill holes with 3.2-4mm drill bit on the next places: 
Take screws, spacers, nuts and install the board. 
Then drill holes for the LED, button and DIN5 connector For example good place at the right side of the keyboard. First step is - drill plastic part, second - drill wood part with bigger wood drill bit and make a canal for wires.
Drill dimensions:DIN5 18mmLED = 4.8-5mm.(better if less 5mm to strong holding in the hole)Push button = 12.5-13mmWiring:Set includes ribbon cable with next dimensions for note and other connections.C (Do) = 90cm. C# (Do diesis) =115cm. D (Re) = 95cm. D# (Re diesis) = 110cm.E (Mi) = 130cm.F (Fa) = 115cm. F# (Fa diesis) = 135cm.G (Sol’) = 105cm. G# (Sol’ diesis) = 120cm.A (La) = 140cmA# (La diesis) = 130cm. B ( Si) = 150cm. MIDI connector, Led, Button = 180cm.Power = 85cm.Bass octave out = 80cmOut to switch board 2x30cm. Farfisa Generators boards
Same shown on MIDI PCB Where @ means note and number of connection points on farfisa (from left to right how is shown on picture).
jFor bass octave sound out need to solder here on PD PS10 
Numbers on MIDI PCB say about the same numbers at the farfisa side. 1-12 on switch board, PD_PS10 on PD contact on the PS10 board.Here is the points and wires number to connect MIDI board out signals to farfisa switch board: shielded wires marked as 1-12. They coming from key contact array
Solder MIDI connector (number for pins marked on the PCB), Led, Button and wires to power supply. 
Here is point to connect: actual voltage under load here is 15V
To teach the MIDI channel, push the black button (LEARN) LED will blink two times and stay ON to wait for MIDI messages. When messages are received LED will blink five times and turn OFF and then will ON with every NOTE ON messages on the selected channel. Now the channel saved to memory and not changed before will be rewritten.
Then drill holes for the LED, button and DIN5 connector For example good place at the right side of the keyboard. First step is - drill plastic part, second - drill wood part with bigger wood drill bit and make a canal for wires.Drill dimensions:DIN5 18mmLED = 4.8-5mm.(better if less 5mm to strong holding in the hole)Push button = 12.5-13mmWiring:Set includes ribbon cable with next dimensions for note and other connections.C (Do) = 90cm. C# (Do diesis) =115cm. D (Re) = 95cm. D# (Re diesis) = 110cm.E (Mi) = 130cm.F (Fa) = 115cm. F# (Fa diesis) = 135cm.G (Sol’) = 105cm. G# (Sol’ diesis) = 120cm.A (La) = 140cmA# (La diesis) = 130cm. B ( Si) = 150cm. MIDI connector, Led, Button = 180cm.Power = 85cm.Bass octave out = 80cmOut to switch board 2x30cm. Farfisa Generators boardsSame shown on MIDI PCB Where @ means note and number of connection points on farfisa (from left to right how is shown on picture).jFor bass octave sound out need to solder here on PD PS10 Numbers on MIDI PCB say about the same numbers at the farfisa side. 1-12 on switch board, PD_PS10 on PD contact on the PS10 board.Here is the points and wires number to connect MIDI board out signals to farfisa switch board: shielded wires marked as 1-12. They coming from key contact arraySolder MIDI connector (number for pins marked on the PCB), Led, Button and wires to power supply. Here is point to connect: actual voltage under load here is 15V To teach the MIDI channel, push the black button (LEARN) LED will blink two times and stay ON to wait for MIDI messages. When messages are received LED will blink five times and turn OFF and then will ON with every NOTE ON messages on the selected channel. Now the channel saved to memory and not changed before will be rewritten.