Due to having more input and outputs pins, this board is the best choice for the Keymmodore Project if you want to have less work on the wiring. With this board keyboard and joysticks have their own separate pins.
Also, another nice feature, is the fact that the C-64 Keyboard connector can be plug directly to the board, there is no need to extensions or adaptors.
The resistors value for the LEDs can change. I choose those looking for colors not being too bright but also uniform. Don’t forgert to insert the resistor for the power LED in case you go for that choice.
The drawing of the DB-9 connectors are inverted to make the diagram easier to read. Look at the corresponding pin numbers.
How to solder the pin strip header to the board
(to plug the keyboard connector directly)
I recommend to solder a strip of 20 pins over each side of the Teensy++2.0. The pins has to be on the components side. Do not buy the already solderer version or solder it otherwise!!!
(well, if you did it already just let me know and I’ll try to make a 3D frames for you. You just need to remove one pin as you can see below)
To be able to plug the keyboard connector directly, you have to shift one position the pin strip of one side, leaving the last pin outside the board.
That’s because C-64 keyboard connector has no hole in Pin 2 working as a «key» preventing to be plug in the wrong direction. Follow the instructions in the pics below.
An advice about Pin D6
Pin D6 has a LED connected to it. You can identify the Pin and the LED indicated with a red rectangle in the picture. If you have a weird behavior, like «ghost» keys pressed, remove the LED. I’ve found some strange issues with the LED. In some boards, the left/right cursor key, also «pressed» the colon key.
It can be easily removed with your soldering iron.