Question about creation of isochronic tone pulses

Hello everybody,

I'd like to create a train of isochronic tone pulses with Csound. Something that looks like the pulses on this image. Please note, that those pulses aren't created just with a simple envelope. The displayed pulses are totally equal in phase and structure and the polarity changes with every single pulse.

I have just a basic experience with Csound and hopefully somebody could give me a hint, how to create something like this. Maybe some special opcode will do the job.

Thanks in advance for your help!

Best regards