Speaking of Dolby, a recent inSync question resulted in me responding that the various Dolby noise reduction schemes are not compatible with one another (see TTOTD 9/17/98). This is true, except for one exception I forgot about (which of course was pointed out by a diligent inSync reader). The exception is that Dolby S noise reduction is somewhat compatible with Dolby B. That is, tapes with Dolby S encoding can be played back successfully using Dolby B noise reduction. I had forgotten that, even though I now remember Dolby making quite a big deal about it at the time Dolby S was introduced.