[{"data":1,"prerenderedAt":109},["ShallowReactive",2],{"connector:at-power-p8-p9:en":3},{"connector":4,"prose":94,"confirmations":108},{"schemaVersion":5,"governance":6,"meta":19,"pins":50},"1.0.0",{"publication":7,"verification":10,"provenance":15},{"status":8,"publishedDate":9},"published","2026-10-24",{"status":11,"verifiedDate":9,"verifiedBy":12,"checklist":13},"verified","Claude (documentary review against IBM Personal Computer AT Technical Reference 1502494, March 1984, pp. 1-57–1-58; pinoutguide.com cross-check; owner GO 2026-10-24; no bench claim)",{"schema":14,"technicalFacts":14,"relationships":14,"sources":14},true,{"sourceUrls":16},[17,18],"https:\u002F\u002Fbitsavers.org\u002Fpdf\u002Fibm\u002Fpc\u002Fat\u002F1502494_PC_AT_Technical_Reference_Mar84.pdf","https:\u002F\u002Fpinoutguide.com\u002FPower\u002FMotherboardPower_pinout.shtml",{"slug":20,"name":21,"title":22,"standard":23,"positionCount":24,"layout":25,"category":26,"source":27,"specs":38,"overview":43},"at-power-p8-p9","AT Power Supply P8\u002FP9 Motherboard Connectors","AT Power Supply P8 and P9 Motherboard Connector Pinout (IBM PC\u002FAT)","IBM Personal Computer AT (1984)",12,"row","power",[28,33],{"label":29,"url":17,"authority":30,"documentType":31,"publisher":32},"IBM Personal Computer AT Technical Reference 1502494 (March 1984), System Board pp. 1-57 and 1-58: power-supply connectors P8 and P9 (table on p. 1-58)","primary","manufacturer_documentation","IBM",{"label":34,"url":18,"authority":35,"documentType":36,"publisher":37},"pinoutguide.com: AT motherboard power supply connector pinout (cross-check: wire colours, side-by-side fitting)","secondary","reference_manual","pinoutguide.com",{"standard":39,"positions":24,"noteKeys":40},"Two 6-position plugs (P8 + P9) on one 12-position header",[41,42],"pages.at-power-p8-p9.overview.notes.view","pages.at-power-p8-p9.overview.notes.order",{"summaryKey":44,"useCaseKeys":45,"beforeYouWireKeys":47},"connectors.atp8p9.summary",[46],"pages.at-power-p8-p9.overview.useCases.boards",[48,49],"pages.at-power-p8-p9.overview.before.blackWires","pages.at-power-p8-p9.overview.before.negative",[51,56,60,64,68,73,76,79,82,86,89,92],{"n":52,"category":53,"signal":54,"role":55,"standardized":14},1,"control","Power good","P8 pin 1: Power good, tells the motherboard that the supply voltages are stable",{"n":57,"category":26,"signal":58,"role":59,"standardized":14},2,"+5V","P8 pin 2: +5 VDC",{"n":61,"category":26,"signal":62,"role":63,"standardized":14},3,"+12V","P8 pin 3: +12 VDC",{"n":65,"category":26,"signal":66,"role":67,"standardized":14},4,"-12V","P8 pin 4: −12 VDC",{"n":69,"category":70,"signal":71,"role":72,"standardized":14},5,"gnd","GND","P8 pin 5: ground",{"n":74,"category":70,"signal":71,"role":75,"standardized":14},6,"P8 pin 6: ground",{"n":77,"category":70,"signal":71,"role":78,"standardized":14},7,"P9 pin 1: ground",{"n":80,"category":70,"signal":71,"role":81,"standardized":14},8,"P9 pin 2: ground",{"n":83,"category":26,"signal":84,"role":85,"standardized":14},9,"-5V","P9 pin 3: −5 VDC",{"n":87,"category":26,"signal":58,"role":88,"standardized":14},10,"P9 pin 4: +5 VDC",{"n":90,"category":26,"signal":58,"role":91,"standardized":14},11,"P9 pin 5: +5 VDC",{"n":24,"category":26,"signal":58,"role":93,"standardized":14},"P9 pin 6: +5 VDC",{"title":95,"description":96,"card":97,"intro":98,"overview":99},"AT Power Supply P8 and P9 Connector Pinout (IBM PC\u002FAT)","AT power supply P8 and P9 pinout from the 1984 IBM PC\u002FAT manual: Power good, +5 V, +12 V, −12 V, −5 V and the four ground contacts that must sit in the middle.","Pair of 6-pin motherboard power plugs used by AT and Baby-AT power supplies.","Before ATX, a PC power supply fed the motherboard through two identical 6-pin plugs, P8 and P9, side by side on one 12-pin header. Select a contact to see its role.",{"notes":100,"useCases":103,"before":105},{"view":101,"order":102},"Positions 1 to 6 are P8 pins 1 to 6 and positions 7 to 12 are P9 pins 1 to 6, in the order the two plugs sit on the motherboard header.","Pin assignments follow the IBM PC\u002FAT Technical Reference (March 1984), page 1-58.",{"boards":104},"IBM PC\u002FAT, Baby-AT and LPX motherboards, from 1984 to the late 1990s",{"blackWires":106,"negative":107},"P8 and P9 are not keyed against swapping. Fit them so that the four ground contacts, P8 pins 5–6 and P9 pins 1–2, are next to each other in the middle; a swapped pair puts the wrong voltages on the board.","The −5 V and −12 V rails served ISA-era chips and serial ports; later ATX supplies dropped −5 V.",null,1793836411316]