Finding datasheets on the net (was Disc analyser news update)

I have never found any useful information on ICs using Google. As you say, you get plenty of sites that claim they can sell you the IC.. COnsideirng that sometimes the number I have entered is a custom part (or an HP house-number or...) I wonder how genuine these ICs are. Or are they any device with the right package renumbered. After all, it it deosn't work in my circuit, that's my fault... I find http://www.datahseetarchive.com/ and http://www.digchip.com/ have many, but by no means lal, of the data sheets I need. For current devices the manufacturer's site generally has a data sheet to download, but a lot of the devices I need data on have been out of prodcution for many years. but the web sites rarely have access to obsolete device data sheets. (I can still rememebnr Motorola sending me photocopies of ancient linear IC data sheets stampped 'This is for inforamtion only, device no longer avaialble' or something like that. Great, it told me what the defective part was and I could design a replacement,) Anyway, fidning data on an IC when you know the neumber is a totally differnt ptoblem to finding out what ICs are avaialble, and what their interesting features are. That I used to do by reading data books. And as I've said repeatedly, I can't do that on the web.