Artifact Details Title System building block 4912B adapter Catalog Number 102629798 Type Physical object Description Handwritten on PCB is "Clock Adapter For R405 or R401 Jumper from Interface To 4407 Replace 4407 Jay MSLEM900 Dec Fig.". The first 4407 has been scratched out. There's also a red tag attached with no writing on it. Date 1965 ca. Manufacturer Digital Equipment Corporation (DEC) Identifying Numbers Model number 4912 Other number 1712-18-PCC On connector in middle of board Part number 4912 B Dimensions overall: 1/2 in x 7 in x 4 1/2 in Category Component/module