VTL/Dutchess logic

Eric Smith eric at brouhaha.com
Sun Oct 10 14:18:36 CDT 2010

  JP Hindin wrote:
> I'm delving deeply into the manuals that came with my IBM System/34 and in
> the Core section it mentions that the logic is "VTL and Dutchess". TTL,
> ECL, CMOS sure... but I've never heard of VTL or Dutchess, and Google
> doesn't seem to be providing (although forest/trees problem exists).
> Is this just another footnote in our history, does it go by another name,
> or am I missing something important here?
As with most everything IBM did in that era, they invented it 
themselves, so no one else used it, and there is little or no documentation.

I'm not sure about VTL, but Dutchess was a specific generation of 
bipolar gate array, containing up to 134 gates.  It was basically 
compatible with normal 5V TTL.

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