Reverse-engineering an IBM Mainframe Vacuum Tube Pluggable Module

In this episode, we get our hands on a pluggable module out of an IBM vacuum tube computer. IBM used these awesome modules that could be pulled out as a unit, and each module consisted of some type of circuit. For example, some were cathode follower buffers, some were dual inverters, and so on. I’m not really sure what this one is, so today, we’re going to see if we can’t figure out how it works! Thanks for watching! Wiring diagram: https://i.postimg.cc/R02jHFm3/Wiring.jpg Schematic: https://i.postimg.cc/cHYPMS1F/Schematic.jpg IBM 604 Engineering Manual: http://www.bitsavers.org/pdf/ibm/604/227-7609-0_604_CE_man_1958.pdf IBM 650 Engineering Manual: http://www.bitsavers.org/pdf/ibm/650/22-6284-1_650_CE_Manual_of_Instruction.pdf Computer picture 1: https://commons.wikimedia.org/wiki/File:IBM_150_Extra_Engineers_1951.jpg Computer picture 2: https://commons.wikimedia.org/wiki/File:Ordenador_IBM650_1959_MUNCYT.jpg Pluggable module picture 1: https://commons.wikimedia.org/wiki/File:RoehreIBM_090325.jpg Pluggable module picture 2: https://commons.wikimedia.org/wiki/File:IBM_700_logic_module.jpg Music: Suco de Melancia by Red Tailed Fox - https://ocremix.org/remix/OCR01671