I am almost certain that my Quartus II web 13.1 program creates RTL schematics with errors in them. (I have not upgraded the installation afterwards because my computer is offline!).

Understood KhaiY. But since the current file worked in Xilinx without the BRAM_16x1S file, it wasn't needed and therefore not given in the mentioned book. And if I had that file I wouldn't know how to add it to the project anyhow. Especially if it can't be added to the existing vhdl file. I already tried to do that previously to get it compiled in Quartus until I found out that it already worked in its present version in Xilinx ISE 14.6.

Thanks.

Best regards.

Albert.