I did the same, built a VGA adapter without using the chip.
It worked fine for 3 or 4 hours then I got a big blue puff of smoke from the back of my A1200 (before I towered it) which fried my video out port. Since then my motherboard can only output video on the rgb or composite ports, can't even use the video port to hook up to a scart TV as I used to.
Fortunatly there was no other serious damage and now I have a graphics card anyway.
In any case I suggest you buy a proper vga adapter or build one with the chip for safety.
Pteppic
