JOHNNIAC

from The Free On-line Dictionary of Computing (8 July 2008)

Johnniac

   <computer> A {mainframe} computer based on a design by {John
   von Neuman} built at the {Institute for Advanced Study}, USA.
   The Johnniac went live in 1953 and was decommissioned in 1966.
   Its memory consisted of 80 special "{Selectron}" {vacuum
   tubes}, each of which held 256 bits of data.

   (2003-06-07)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

JOHNNIAC
       JOHN von Neumann Integrator and Automatic Computer