[amsat-bb] Digital sats

I have a question regarding digital birds.

What space objects can I pick up with a TNC, and what birds do I need a special modem for ?

Some that come to mind, that I can use a TNC for are

+ ISS 1200 Baud AFSK + PCSAT 1200 Baud AFSK

Is the aim to have birds launch that obey

+ AX25 encoded packets + 1200 or 9600