I haven't closely examined many different computer PSUs. The ones I've taken apart are mostly cheap Chinese ones and they're all closely similar. Most of them use a TL494 or an SG3525 as the PWM controller. Today, I happened to look at an old ATX PSU PCB which uses a chip I'm not familiar with. The number is LPG-899 and it has "Linkworld" printed in cursive font. The logo is a filled triangle with a globe inserted half way on one side. Curious, I searched for a datasheet but couldn't find one. That made me even more curious and I kept on searching for some time, without success.
It's in a 16-pin DIP package but the pin-outs are different from the ones I know about. The push-pull outputs are taken from pin 7 and 8, driving two C945 transistors (Japanese low-power NPNs) which in turn drive the output transistors.. The +5V output of the PSU is fed back directly to pin 2, so this looks like Vcc. The +12V output is goes via a resistive voltage divider to pin 3. Pin 5 is grounded. I didn't check the rest. Is anyone familiar with this IC?