> I'm not sure what exactly is different between the two The 76477 (http://www.vgmpf.com/Wiki/images/4/40/SN76477_-_Manual.pdf http://www.vgmpf.com/Wiki/images

> I'm not sure what exactly is different between the two The 76477 (http://www.vgmpf.com/Wiki/images/4/40/SN76477_-_Manual.pdf http://www.vgmpf.com/Wiki/images/4/40/SN76477_-_Manual.pdf) has more pins and uses them to bring out more of the controls. The noise-clock in particular is controllable by anything that sinks its 'resistor' pin's current to ground, so a simple NPN sink driven by a slow sawtooth will smoothly vary the noise output from a 'tiktiktik' to a roar. The 76495 doesn't make that control available.