If you get the "Sorry, the file cannot be displayed. There seems to be a technical issue ..." error when trying to view an image, a workaround is to click on the cog icon in the upper right side of the media viewer, and then select "Disable Media Viewer". We are aware of the problem and are looking for a solution.
The Tektronix 50M40 is a relay scanner card for the MI5010.
From Tekscope Volume 13 Number 3, September 1981 page 6:
The 50M40 Programmable Relay Scanner Card serves as a low-frequency scanner accommodating up to 16 inputs or outputs. The card contains 16 mercury-wetted relays that can be configured 16-to-1, 8-to-1, or 4-to-1 by positioning jumpers. Typical uses include control of larger relays, scanning a multimeter input over several signal points, turning on lights or audible indicators, and so forth.