CNCZone's own slp_prlzys has a new interface design. Taking a different path, there is a header for a DB25 ribbon cable. Screw terminals for the signal I/O lines, switch interface, rectifier, connection for off board LED's, Estop. Thanks Mhel!
The other is an update of the Optically Isolated Interface Board. 4 axis, high speed optos, USB connector to support the isolators 5V input requirement from your PC.