[HH] drive two monitors with a Raspberry Pi

[Tom Metro]

Gert van Loo (of Gertboard fame) figured out how to get the Raspberry
Pi's GPU to drive the GPIO pins, which if equipped with a simple
resistive ladder D-to-A converter, can then drive a VGA monitor. Between
that and the existing HDMI port you can drive two displays. Clever.

http://hackaday.com/2014/09/10/raspberry-pi-gets-vga-dual-screen-support/

(Required a model B+ in order to have enough GPIO pins.)

 -Tom