2nd VGA output from DE1

I have a design which can output either

a) text screen, 1 bit R, 1 bit G, 1 bit B, at 60Hz

b) graphics screen, 4 bit R, 4 bit G, 4 bit B, at 50Hz or 60Hz

to the VGA connector, and I have one of the switches select which.

I would like to be able to see both of these outputs at once, on two separate VGA monitors.

Part of the reason for two monitors is the fact the refresh rates may not always agree.

The other reason is that its just more usable this way.

So I figure I'd hook up one monitor to the VGA connector, and display the graphics on it, taking advantage of the 3x 4 bit VGA DACs already on the DE1 board.

The text mode screen, is much simpler, only having 8 colours.

So I figure I could drive the VGA signals onto the GPIO pins, and then make a GPIO to VGA connector.

In principle this sounds easy, but I'm a little concerned about the voltages and currents required, as I know virtually nothing about the analog side of electronics (its all '1's and '0's to me).

http://www.fpga4fun.com/ponggame.html shows that such a circuit might be easy, but requires some resistors of the right values.

What would a similar circuit look like for bridging Altera DE1 GPIO to VGA?

Particular resistor values? I don't want to fry my board.

I presume the GPIO connector has a suitable GND to use?

Some output pins better to use than others? Some "buffered", some not?

Any special pin assignment settings required in Quartus?

{{{ Andy