IMPORTANT: Note that RAMPROM monitors the Vcc line of the serial PROM. If an uninitialised XTB is connected to a PROM socket which then has power applied, there will be a 5-volt supply to a pin of the unconfigured Xilinx chip on the XTB. This may damage it. Always make sure that the XTB is configured before you power-up your circuit, and that you remove the power from the circuit if the XTB should lose its configuration or be programmed with another one. There should really be a resistor in the line to protect against this.
Here are the connections for a RAMPROM cable:
