A plugboard or control panel is an array of jacks or sockets into which patch cords can be inserted to complete an electrical circuit. Control panels are sometimes used to direct the operation of unit
IBM 402 accounting machine control panel wiring. This board was labeled "profit & loss summary."
Reverse side of the same 402 plugboard, showing the pins that make contact with the machine's internal wiring. The holes were called hubs.
An operator inserting a control panel into an IBM 407 Accounting Machine Another panel is on the floor nearby.
An 80-column punched card. Rows 0 to 9 are labeled. The 12 row, on top, has one punch in column 7. The 11 row, below it is not punched on this card. As cards passed through a read station, usually 9-edge (bottom edge) first, wire brushes, one for each column, would make contact through the holes.
The IBM 602 Calculating Punch, introduced in 1946, was an electromechanical calculator capable of addition, subtraction, multiplication, and division. The 602 was IBM's first machine that did division
Electromechanical memory module from IBM 602 machine