[QuadList] Servo Modes

[Don Norwood]

Hi Dennis:

I agree. But wasn't the use of wire-wrap also due to board density requirements?  I don't think multi-layer (other than double-sided) pcb's were common at the time.  Here are a couple of pics (front & back) of a reference sync processor from an early 70's Ampex VPR-7900.  I don't think that level of density would have been possible with a double-sided board.  The wire-wrap system is quite reliable, and this board is still functioning perfectly 40 years later.





Don Norwood
Digitrak Communications, Inc.
www.digitrakcom.com

----- Original Message ----- 
From: "Dennis Degan" > 
> I query:
> 
> Have you ever tried to mod a printed circuit backplane?  It might be  
> easier to get to the traces, but it's STILL can be a major PIA.   ;)
> 
> Dennis Degan, Video Editor-Consultant-Knowledge Bank
>      NBC Today Show, New York
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