Is there some way for me to connect old technology to airplay?
There is no external hardware to use airplay, if your aim is specifically to connect your MBP to AppleTV through AirPlay I think you are out of luck. There may be very tricky ways of doing this, although much of the encoding used in AirPlay is done by hardware(I believe Intel chip) that your laptop doesn't have (as far as I know). 

There are other options though for wirelessly connecting your laptop to a screen, but thats out of scope I guess.