Issue No. 04 - October-December (1992 vol. 14)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/85.194055
<p>EDSAC 2, which came into operation early in 1958, was designed by the team that had successfully built and operated EDSAC 1, and embodied the experience obtained with that machine. EDSAC 2 was the first computer to have a microprogrammed control unit, and it established beyond doubt the viability of microprogramming as a basis for computer design - this in spite of the fact that vacuum tubes were far from ideal for the purpose. At the mechanical level of organization, EDSAC 2 was packaged in a bit-sliced manner, with interchangeable plug-in units. This method of packaging was well matched to the vacuum tube technology of the period, and its expected advantages - arising from the replication of units - were fully realized. The article gives a description of the principal hardware features of EDSAC 2.</p>
M. V. Wilkes, "Edsac 2," in IEEE Annals of the History of Computing, vol. 14, no. , pp. 49-56, 1992.