That's exactly what you need, carvedeye.

I've used one of those myself, but it was WAAAAAY back, & now I can't remember how it was done except that involved terminal software on each machine. (like what you would use to access one of the old dialup BBS's)
If memory serves, the Amiga end was easy, but (typically) the PC end was more difficult to set up.
No doubt someone here will be able to explain better.