Raspberry Pi only has digital HDMI signals. They are compatible with a DVI-D monitor, but not VGA. You need a converter box to convert the digital signals to VGA analog signals. There's a lot of information at the RasPi Hardware Wiki here and here.
DVI as produced by most PC video cards is DVI-I, which has pins for bit-serial digital signals (DVI-D) and other pins for VGA analog (DVI-A). Since a PC video card has both, you just need a cable to attach it to a DVI-D monitor or a VGA monitor. But this doesn't work with RasPi, since it only has digital on the HDMI connector.
Raspberry Pi only has digital HDMI signals. They are compatible with a DVI-D monitor, but not VGA. You need a converter box to convert the digital signals to VGA analog signals. There's a lot of information at the RasPi Hardware Wiki here and here.
DVI as produced by most PC video cards is DVI-I, which has pins for bit-serial digital signals (DVI-D) and other pins for VGA analog (DVI-A). Since a PC video card has both, you just need a cable to attach it to a DVI-D monitor or a VGA monitor. But this doesn't work with RasPi, since it only has digital on the HDMI connector.
