National Institute of the Republic of Serbia
ὅδε οἶκος, ὦ ἑταῖρε, μνημεῖον ἐστιν ζωῶν τῶν σοφῶν ἀνδρῶν, καὶ τῶν ἔργων αὐτῶν
The RAM module with ferrite cores, developed in the early 1950s, was a revolutionary type of random-access memory (RAM) that transformed computing. Jay Forrester and his team at the Massachusetts Institute of Technology (MIT) created the first prototype in 1951 to overcome the limitations of earlier memory systems such as delay lines and vacuum tubes, which were slower and less reliable. These modules had a capacity of 4Kb or 8Kb and were a key component of early digital computers. The memory capacity was determined by counting the ring-shaped magnetic cores—toroids—where each toroid represented one bit. By counting the toroids along the length (x), width (y), and height (z), the capacity in bits was calculated as the product xyz. Dividing xyz by 8 provided the capacity in kilobytes (KB). Ferrite core technology was widely used during the 1950s and 1960s in scientific, industrial, and military systems, such as the SAGE air defense network. Its reliability and speed enabled real-time data processing, marking a significant step toward the development of modern computing systems and laying the foundation for today’s memory technologies.
Creator: Jay Forrester, 1950-1960
Source: Gift of Žarko Mijajlović
Text prepared by Žarko Mijajlović
Photo by Dragan Aćimović
