Solid State Music - IO4 Board
This is a 2 parallel, 2 serial IO port board.  A very flexible and useful board.

The Serial ports were two fully functional with full handshaking using LSI UART chips.   Baud rates were from 55 up to 9600. The two parallel ports were had latch buffers using two 8218's.  Port addressing was quite flexible, serial on any 4 port boundary. parallel on any two port boundary.  The ports could be set to trigger interrupts.
  
The manual for this board can be obtained here.