Artifact Details Title Sense switch 1981A system building block Catalog Number 102728517 Type Physical object Description The object consists of a green board with an aluminum frame and a blue plastic connector. There are three rows of transistors and various resistors on one side. On the other side there is a solder circuit and a grid lettered A-Z. Date 1963 ca. Manufacturer Digital Equipment Corporation (DEC) Place Manufactured Maynard, Mass. Identifying Numbers Model number 1981 A Printed in solder near the insertion end Other number 1981 Stamped into the face of the aluminum frame Serial number 0124553 Dimensions overall: 1/4 in x 4 1/2 in x 7 in Category Component/module