Use the Data Recorder on the Famicom without the keyboard?

Hello everyone!

So I saw this schematic on the nesdev wiki and would love to do this to my Famicom. It's a circuit that allows you to use the Famicom Family BASIC Data Recorder on the NES without the Famicom Family BASIC keyboard. I looked up a pinout of the NES expansion port and the Famicom 15 pin expansion port and found the required signals to be on both connectors:

NES pin 1 equals Famicom pin 15
NES pin 2 equals Famicom pin 1
NES pin 12 equals Famicom pin 13
NES pin 43 equals Famicom pin 12




My question is can someone please identify some of these components in the schematic? I'm assuming C1 47n means a 47uf capacitor and so on for the caps? What does the symbol connecting C1 to NES EXP. PIN 1 mean? What's up with the black rectangle on C3? Also, what is U1? Is it a transistor?

Any help would be highly appreciated!

 

C1 - 3,3uF polar capacitor, black rectangle means minus (negative electrode). U1 is an operational amplifier, very common one. Google will give you the datasheet in the first 3 links.