The part number you listed in your post is for a printing mechanism, not a whole printer (just the mechanics). You would still need a so-called interface board with the actual printing electronics.
The one capable of serial communication goes by the name FTP-628DSL305R. Click on the link and look at the picture. Does that look like a project one might come up with while discussing on a forum?
If you do have the board, interfacing it to a 8051-based µC is easy: throw a **broken link removed** in the mix between µC's UART and the Rx/Tx of the printer's interface board.
This would pretty much take care of the electronics.
When you've completed this part of your project, welcome back to take a look at the software as well.