Async logic

[Alexey Toptygin]

On Sun, 21 Mar 2010, Brad Parker wrote:

> Now I will make one caveat.  A lot of the early DEC designs used pulse 
> or asynchronous logic.  I would avoid that.  I would stick with 
> completely synchronous design.  So, if you are reading an old book and 
> it talks about async design, I'd skip that part.  Certainly anything 
> from Mick & Brick on is fully synchronous.

What's wrong with pulse or async logic designs? I personally find them 
fascinating, but I've never gotten to play with an implementation of 
one... Are there problems with designing like this that made people switch 
to sync designs? Anyone know of any good books on non-synchronous logic 
design?

 			Alexey