What is this NES slot for? (Patreon)

Morning folks,

I've had to rush this one through a bit, as it has been my son's birthday this week, and apparently I've been incredibly busy. Also, I've had no sleep and I'm about to go to some kind of "Covid Safe" theme park, so it might still be uploading for the next half hour or so.

Hopefully it's still up to scratch and provides some brief respite.

Comment below if you notice anything glaring.

Have a great weekend!

Pete