http://f4hla.free.fr/
Uppon the request from Jean-François, f1pdx, I have build a simple CW generator for ATV beacon, but it is easily adaptable to any application.
Below is the schematic and the veroboard layout. The software to burn in the PIC is available here for PIC16F84 and there for PIC16F628. Relatives source codes are available here: PIC16F84 and PIC16F628.
From the electrical schematic point of view, please understand that the Quartz+capacitor parts are only needed in the case of 16f84.