IBM Pluggable Unit - A Vertical Circuit Board

About this Artwork This artwork is a mixed media display celebrating the IBM Pluggable Unit. In 1947, Ralph Palmer invented the IBM Pluggable Unit to meet the technology needs of the IBM 604 Electronic Calculating Punch. Although it had many of the functions of a modern computer, the 604 was not a computer in that it did not have a stored program and was governed by the card reading process. IBM anticipated the IBM 604 would be sold in the thousands. The challenges of building, testing, and maintaining this many electronic machines had never before been considered. IBM had only made 100 of the first electronic calculators in production. This was the IBM 603 Electronic Multiplier. The Pluggable Unit was the solution for the 604. Because the Pluggable Unit had a vertical dimension rising off the flat circuit board, it provided greater circuit density and space savings. Each Unit was a simple circuit and could be tested independently of the 604 machine. If any component of the circuit was