A bit count instruction would be very handy in a project I've been working on lately, which is a new packet radio link level protocol for amateur packet radio. This protocol uses forward error correction, so it needs a highly reliable way to delimit the start of each physical link frame. A pseudo-random "sync" sequence is the standard way to do this, and you detect it with a correlator. The bit count instruction would come in handy here, since the only other fast way to do it is to use table lookup. Phil