CompuPro - Interfacer II
The Interfacer-II was a triple parallel single serial channel (RS-232) board designed specifically for full electrical and mechanical compatibility with the IEEE 696/S-100 standard.

Features, such as full RS232 handshaking, a crystal controlled baud rate generator, a reliable hardware UART, three full duplex parallel I/O ports with handshaking and interrupts and a selectable rate interrupt clock allow for maximum flexibility in almost any system. The serial channel could be addressed as a 2 port black anywhere within an 8 bit's CPU 265 byte I/O space. The baud rate was switch selectable. A 1602 UARD chip was used. The parallel ports I/O ports can be a block of 4 ports anywhere in the 256 byte address space. One status port and 3 actual ports.
 
The manual for this board can be obtained here.

 

Other CompuPro S-100 Boards
CPU8085-88  CPU86-87  CPU-Z  Disk1  Disk1A  Disk1B  Disk2  Disk3   EconoROM2708  Interfacer 1  
RAM Boards   Interfacer 3  Interfacer 4  Interfacer II   M-Drive  MPX-Board  PC-Video  
System-Support1  System-Support2   SPIO  Spectrum  SP186   CPU-286   68000  32016  SPUZ