Just a simple passive DAC. Design was done in ExpressPCB software. Design file.
Cut them apart with a Dremel tool carbide wheel. The DE0 pin numbers are marked on the board. You need to build a hardware VGA driver, of course. The Verilog code for one simple driver, a memory block, and a simple line routine for QuartusII. Olivia Gustafson and Alex Jaus wrote much of the Verilog.