The diagrammatic view of the 1950-1 Maze-solving Mouse built by Claude A. Shannon.
Claude Shannon knew Edmund C. Berkeley quite well. Berkeley had two young associates working part-time with him on his early robots, by the names of Ivan and Bert Sutherland. Ivan was soon to have Claude Shannon as his Thesis supervisor. Berkeley was keen to add a maze-solver to his catalogue of small robots, and engaged the Sutherland brothers to build one. This was called "Franken" and will be subject to a later post. Shannon put together the two page document to assist Berkeley and the Sutherland brothers in their quest.
Although there are "indicating lamps" marked in the schematic, I cannot confirm that the above photo is of those indicators in that version of the maze-solving mouse.
I have not been able to confirm how many maze-solvers were built, both by Shannon and later copies by Bell Labs. We have a reasonable description of the 1951 model as it was presented to the Eighth Conference on Cybernetics. More information is available is on the later 1952 "Theseus" mouse model. See a later post on this, more well known version here.
The pdf of the 1951 paper titled "Presentation of a Maze-Solving Mouse" from the Eighth Conference on Cybernetics is available here ShannonsMaze51 .
Although the paper was presented in 1951, I believe this first version of Shannon's maze was built in 1950.