HP9836C colour alignment (grey scale tracking)

[Tony Duell]

> 
> > I notice that edge connectors are a lot less common than they used to
> > be.  I wonder if there are reliability issues by comparison with
> > other typies?
> 
> What's the difference between an "edge connector" and, say, the
> connector used for a PCI card or a modern peecee memory stick?  (Tony,
> I realize you may not be familiar with either one, but just wander into
> a mass-market computer store and I'm sure you can find plenty of each,
> probably with some examples in see-through packages.)

Last time I saw a PCI card and a PC motherboard that took it, the 
connector was certainly what I would call an 'edge connector. A finer 
pitch han the ISA one, but still an edge connector

I have to admit the latest memory modules that I've handled are SIMMs. 
The connector on those is _close_ to being an edge connector, but I 
wouldn't call it one. The pads on the SIMM are like the pads for an edge 
connecotr, but you don't push it into the socky, you put it in at an 
angle and that lift it into the clips. This means the contacts are a 
pressure type of thing, not a wiping contact as in the edge connector.

> The only difference I can see is how the "socket" side of the
> connection is usually mounted (so the socket and board edge mate
> perpendicular to the baord the socket is connected to, rather than

Actually, that's very common with older edge connectors too. Think of ISA 
cards, they're perpendicular to the motherboard. Or the boards in this 
9836. Or S100 boards. Or...

> parallel).  Oh, and the size of the contact fingers, I suppose, but
> _that_ surely doesn't count!

Indeed it doesn't 

-tony