This is a control panel blank that appears to be related to a disk drive or disk drive controller: all of the sections of the panel refer to the classic magnetic disk addressing scheme of cylinder/head/sector, data handling, and error…
This modem was used primarily to connect a terminal (typically a VT100 or VT52) to a remote computer system over local telephone lines. It communicated at 300 or 1200 bits/second (baud).
This is the processor for the PDP-8/e, a (relatively) low-cost minicomputer model that was introduced in 1970. (The PDP-8/e was sold with a tape drive, terminal, and cabinets that we do not have.)