SBC6120 (a build-it-yourself PDP-8 clone) Last Buy and EndofLife - test-drb@ccmp.vtda.org

5 Jun 2006

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Subject: Re: SBC6120 (a build-it-yourself PDP-8 clone) Last Buy and EndofLife
   From: William Donzelli <aw288 at osfn.org>
   Date: Mon, 05 Jun 2006 14:49:06 -0400 (EDT)
     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>

  Oh, and anything you want to be reliable......

Also, when sockets are used in large quantities, manufacturing yield takes
a dump. We have all mashed a pin or two in our lifetimes, trying to get
something inserted (anyone that hasn't is a liar!). Now multiply that by
several orders of magnitude on the assembly floor.

ENgineers should try there best to avoid sockets. Period.

William Donzelli
aw288 at osfn.org 
I use them where there are programable parts that can't be blasted in
circuit.  Sometimes when the part used is a temporary sub (74ls for a 74HCT).
My preference is machined pin or the better sidewipe when I have to.

However my worst experiences are socketed board for failures that 
were the socket itself.  TI and RN made a edgewipe that was the absolute
pits for relibility. By edgewipe I mean the narrow edge of the pin
not the wider face.  I've desocketed 4 NS* MDS controllers that used them
both kit and factory and all had no bad parts but plenty of inop sockets.

Allison