Have a look at these links:
- https://wiki.friendlyelec.com/wiki/imag ... rfaces.pdf
- https://wiki.friendlyelec.com/wiki/imag ... rfaces.pdf
- https://wiki.friendlyelec.com/wiki/imag ... 231016.pdf
Schematics:
- https://wiki.friendlyelec.com/wiki/imag ... 09_SCH.PDF
- https://wiki.friendlyelec.com/wiki/imag ... 04_SCH.pdf
CAD:
- https://wiki.friendlyelec.com/wiki/imag ... 04_DXF.zip
Cheers !

HP_