I take that back, it's intermittent. Sometimes it works, sometimes it doesn't.

Sometimes it works up until I try to "Q" the player to the shell prompt, then I get garbage and I can't see anything from the player (but my typed commands still work and I can type "exit" and get the player to restart).

Must be an intermittent wiring connection somewhere, I guess I should actually solder the connections instead of crimping them.