This information may be shared freely but not sold for profit! This data is provided in a text format to allow greater ease of cutting and pasting into various technical documents. This information compiled and provided by Dick Perron dperr@randomc.com Standard PC Cabling Pin-out Diagrams Standard motherboard power connectors ATX motherboard power connector CGA/EGA/VGA Video connectors DB13W3 Mono and Color video connectors AT and PS/2 keyboard connectors PS2/Serial mouse adaptor PS2/Serial mouse connectors IBM and EVEREX serial ribbon cable pinout Serial I/O connectors Game Port Connector Reset/keylock/battery/speaker/HDD/turbo MB connectors Parallel I/O connectors Serial Loopback Plug Wiring Parallel Loopback Plug Wiring Win95/98 Direct Cable Connection (Serial and Parallel) Null modem cable PC to PC Null modem cable PC to serial device Parallel Centronics cable MIDI In and Out connectors IR module connector USB Canle Connector 10baseT/100baseT crossover cable 100baseT4 crossover cable ******************************************************************************* CENTRONICS/DB STYLE CONNECTOR PIN NUMBERING Rule of thumb for pin numbering for standard and mini Centronics/DB style connectors is: Male Connectors Pin #1 is the first pin, top row, LEFT side when looking at the connector. Female Connectors Pin #1 is the first pin, top row, RIGHT side when looking at the connector. DIN/MINI-DIN CONNECTORS DIN and Mini-Din connectors have an alternating pin numbering scheme. See diagrams in this document for correct pin orientation. ****************************************************************************** STANDARD PC MOTHERBOARD CONNECTORS Main Board (System PCB) Standard DC Power Connector(s) O Y r e B B B B W a l B l l l l h n R l l a a a a i R R R g e o u c c c c t e e e e d w e k k k k e d d d ___________ ____________ | | | | | P8 | | P9 | | | | | ----------- ----------- Wire Color Assignment Black ------------------------------- Ground Orange -------------------------- Power Good (+5V DC) Red ---------------------------------- +5 VDC White --------------------------------- -5 VDC Yellow ------------------------------- +12 VDC Blue -------------------------------- -12 VDC Note!! When installing the P8/P9 connector be sure that the four black wires are adjacent to each other in the center of the connector. The Red and Orange wires are on the outside edge of the connector. ATX 20 pin power connector Pin# Pin# ----------------------- | 3.3V 11 1* 3.3V | | -12V 12 2 3.3V | | COM 13*(Gnd) 3 COM | | PS-ON 14* 4 +5V | | COM 15 5 COM | | COM 16 6 +5V | | COM 17 7 COM | | -5V 18 8 PW-OK| | +5V 19 9 5VSB | | +5V 20 10 +12V | -------------------------- * NOTE!! On ATX supplies the power supply on/off functions are controlled thru the motherboard connector. See pins 1, 13 and 14 for 3.3V, GND and power on signal. Peripheral DC Power Connector Y B B e l l l R a a l e c c o d k k w Wire Color Assignment Red ------------------------------- +5 VDC Black ------------------------------ Ground Yellow ----------------------------- +12 VDC IBM AT 101 KEY (ENHANCED) KEYBOARD 5 PIN DIN CONNECTOR Male End PIN SIGNAL Female End 1 ---------------------------------- KBDCLK (clock) 1 3 2 ---------------------------------- KBDAT (data) 3 1 4 5 3 ---------------------------------- KBRST (reset,not used) 5 4 2 4 ---------------------------------- GND 2 5 ---------------------------------- VCC (+5V) IBM PS/2 KEYBOARD 6 PIN MINI-DIN CONNECTOR Male End PIN SIGNAL 5 H 6 1 -------------------------------- KBDAT (data) 3 4 2 -------------------------------- not used 1 2 3 -------------------------------- GND 4 -------------------------------- VCC (+5v) 5 -------------------------------- KBCLK (clock) 6 -------------------------------- not used IBM PS/2 MOUSE 6 PIN MINI-DIN CONNECTOR PIN SIGNAL 6 H 5 1 ------------------------------- MOUSEDATA: 110 4 3 2 ------------------------------- not used 2 1 3 ------------------------------- GND 4 ------------------------------- +5V Female end 5 ------------------------------- MOUSECLK: 110 6 ------------------------------- not used PS/2 MOUSE ADAPTOR CABLE TO MOTHERBOARD 10 PIN DIL CONN Mouse port DIL Conn 1 ------------------------------- 1 Data 2 ------------------------------- 2 N/C 3 ------------------------------- 3 Gnd 4 ------------------------------- 4 VCC +5V 5 ------------------------------- 5 Clk NOTE!! This pinout is from a Biostar MB with PS2 mouse option. This PS2 to DIL connector cable IS NOT STANDARD across all MB mfg's. There are some 4 pin , 5 pin and 10 pin DIL connectors on various MB's. SERIAL MOTHERBOARD CABLE 10 PIN DIL TO DB-9 (IBM WIRING SCHEME) This is the ribbon cable from the MB serial connector to the DB-9/DB-25 COM connector DIL DB-9 DB-25 1 -------------- 1 DCD __________ 8 6 -------------- 2 RX ___________ 3 2 -------------- 3 TX ___________ 2 7 -------------- 4 DTR __________ 20 3 -------------- 5 GND __________ 7 8 -------------- 6 DSR __________ 6 4 -------------- 7 RTS __________ 4 9 -------------- 8 CTS __________ 5 5 -------------- 9 RI ___________ 22 10 ------------- 10 N/C OR KEY SERIAL MOTHERBOARD CABLE 10 PIN DIL TO DB-9 (EVEREX WIRING SCHEME) This is the ribbon cable from the MB serial connector to the DB-9/DB-25 COM connector DIL DB-9 DB-25 1 -------------- 1 DCD __________ 8 2 -------------- 2 RX __________ 3 3 -------------- 3 TX __________ 2 4 -------------- 4 DTR __________ 20 5 -------------- 5 GND __________ 7 6 -------------- 6 DSR __________ 6 7 -------------- 7 RTS __________ 4 8 -------------- 8 CTS __________ 5 9 -------------- 9 RI __________ 22 10 ------------- 10 N/C OR KEY MICROSOFT SERIAL MOUSE DB-9 CONNECTOR PIN SIGNAL 1 -------------------------------- MOUSEDATA 5 -------------------------------- Gnd 8 -------------------------------- +5V 9 -------------------------------- MOUSECLOCK PS2/SERIAL MOUSE ADAPTOR CABLE MINI DIN CONN DB-9 SERIAL CONN 1 ---------------------------------- 1 3 ---------------------------------- 5 4 ---------------------------------- 8 5 ---------------------------------- 9 GAME PORT DB-15 FEMALE PIN SIGNAL 1 -------------------------------- +5V DC 2 -------------------------------- Button 4 (A_PB1) 3 -------------------------------- Pos'n 0 (A_X) 4 -------------------------------- GND 5 -------------------------------- GND 6 -------------------------------- Pos'n 1 (A_Y) 7 -------------------------------- Button 5 (A_PB2) 8 -------------------------------- +5V DC 9 -------------------------------- +5V DC 10 -------------------------------- Button 6 (B_PB1) 11 -------------------------------- Pos'n 2 (B_X) 12 -------------------------------- GND 13 -------------------------------- Pos'n 3 (B_Y) 14 -------------------------------- Button 7 (B_PB2) 15 -------------------------------- +5V DC KEYLOCK AND POWER LED CONNECTOR PIN SIGNAL 1 -------------------------------- +5 VDC 2 -------------------------------- not used (key) 3 and 5 -------------------------- GND 4 -------------------------------- KEYBD DIS (key lock) EXTERNAL BATTERY CONNECTOR (6 VDC) PIN SIGNAL 1 -------------------------------- +6 VDC 2 -------------------------------- not used (key) 3 -------------------------------- GND 4 -------------------------------- GND SPEAKER CONNECTOR PIN SIGNAL 1 -------------------------------- SPEAKER 2 -------------------------------- not used (key) 3 -------------------------------- GND 4 -------------------------------- +5 VDC TURBO LED CONNECTOR PIN SIGNAL 1 -------------------------------- +TURBO (+5 VDC) 2 -------------------------------- GND DISK ACCESS LED CONNECTOR PIN SIGNAL 1 -------------------------------- +DISK (+5 VDC) 2 -------------------------------- -DISK 3 -------------------------------- -DISK 4 -------------------------------- +DISK (+5VDC) ENHANCED GRAPHICS ADAPTOR (EGA) VIDEO CONNECTOR DB-9 DB-9 PIN female SIGNAL DB-9 MALE CONN 1 -------------------------------- GND DB-9 FEMALE CONN 1 5 2 -------------------------------- SECONDARY RED 5 1 o o o o o 3 -------------------------------- RED o o o o o o o o o 4 -------------------------------- GREEN o o o o 6 9 5 -------------------------------- BLUE 9 6 6 ---------------------- SECONDARY GREEN/INTENSITY 7 ---------------------- SECONDARY BLUE/MONO VIDEO 8 -------------------------------- HORIZ RETRACE 9 -------------------------------- VERT RETRACE VIDEO GRAPHICS ARRAY (VGA) HDD-15 CONNECTOR HDD-15 PIN female SIGNAL HDD 15 MALE CONN 1 -------------------------------- RED HDD 15 FEMALE CONN 1 5 2 -------------------------------- GREEN 5 1 o o o o o 3 -------------------------------- BLUE o o o o o 6 o o o o o 10 4 ------------------------- MONITOR ID BIT 2 10 o o o o o 6 o o o o o 5 -------------------------------- DIGITAL GND o o o o o 11 15 6 --------------------------- RED ANALOG GND 15 11 7 --------------------------- GREEN ANALOG GND 8 --------------------------- BLUE ANALOG GND 9 ------------------------------ not used 10 -----------------------------SYNC RETURN (GND) 11 ------------------------ MONITOR ID BIT 0 (not usually used) 12 ------------------------ MONITOR ID BIT 1 (not usually used) 13 ----------------------------- HORIZ SYNC 14 ----------------------------- VERT SYNC 15 ----------------------------- not used WORKSTATION VIDEO GRAPHICS DB13W3 CONNECTOR DB13W3 female COLOR SIGNAL DB13W3 MALE CONN 1 -------------------------------- N/C DB13W3 FEMALE CONN 1 5 2 -------------------------------- N/C 5 1 o o o o o 3 -------------------------------- SENSE2 o o o o o @ o o o o o @ @ 4 ------------------------- -------SRTN @ @ o o o o o @ A1 6 10 A2 A3 5 -------------------------------- CSYNC A3 A2 10 6 A1 6 -------------------------------- N/C 7 -------------------------------- N/C 8 -------------------------------- SENSE1 9 -------------------------------- SENS0 10 ------------------------------- CRTN A1 ------------------------------- RED A2 ------------------------------- GREEN A3 ------------------------------- BLUE DB13W3 female GREYSCALE (MONO) SIGNAL 1 -------------------------------- N/C 2 -------------------------------- N/C 3 -------------------------------- SENSE2 4 -------------------------------- SRTN 5 -------------------------------- CSYNC 6 -------------------------------- N/C 7 -------------------------------- N/C 8 -------------------------------- SENSE1 9 -------------------------------- SENS0 10 ------------------------------- CRTN A1 ------------------------------- N/C A2 ------------------------------- GREEN A3 ------------------------------- N/C NOTE!! Most workstation monitors using DB13W3 connectors are FIXED FREQUENCY or are sync on green monitors and cannot be used as standard VGA monitors on a PC without a special GRFX card to match the horiz/vert frequency requirements of the monitor. COLOR GRAPHICS ADAPTER (CGA) VIDEO CONNECTOR DB-9 DB-9 PIN Female SIGNAL 1 --------------------------------- GND 2 --------------------------------- GND 3 --------------------------------- RED 4 --------------------------------- GREEN 5 --------------------------------- BLUE 6 ------------------------------- INTENSITY 7 -------------------------------- not used 8 ------------------------------ HORIZ SYNC 9 ------------------------------ VERT SYNC MONOCHROME ADAPTOR DB-9 DB-9 PIN Female SIGNAL 1 --------------------------------- GND 2 --------------------------------- GND 3 ------------------------------- not used 4 ------------------------------- not used 5 ------------------------------- not used 6 ----------------------------- +INTENSITY 7 ------------------------------- +VIDEO 8 ------------------------------ +HORIZ SYNC 9 ------------------------------- -VERT SYNC PARALLEL PRINTER CONNECTOR DB-25 DB-25 PIN (Female) SIGNAL DB-25 MALE CONN 1 ------------------------------- > STROBE * DB-25 FEMALE CONN 1 13 2 ------------------------------- > DATA 0 13 1 ooooooooooooo 3 ------------------------------- > DATA 1 ooooooooooooo ooooooooooo 4 ------------------------------- > DATA 2 ooooooooooo 14 25 5 ------------------------------- > DATA 3 25 14 6 ------------------------------- > DATA 4 7 ------------------------------- > DATA 5 8 ------------------------------- > DATA 6 9 ------------------------------- > DATA 7 10< ------------------------------ ACK * 11< ------------------------------ BUSY 12< ------------------------------ PAPER END 13 ------------------------------ SLCT (select) 14 ------------------------------ >AUTOFEED * 15< ------------------------------ ERROR * 16 --------------------------->INITIALIZE PRINTER * 17 ------------------------------- SLCTIN (select in) 18 thru 25 ----------------------- GND Note!! * denotes an active low signal. DB-25 MALE PARALLEL LOOPBACK CONNECTOR WIRING 1 to 13 Strobe to select 2 to 15 Data o to ERROR 10 to 16 ACK to INIT 11 to 17 BUSY to SLCTIN 12 to 14 PAPER END to AUTOFEED SERIAL I/O PIN OUTS RS-232 SERIAL (COM) PC PORT CONNECTOR DB-9 DB-9 PIN (Male) FUNCTION ABBREVIATION 1 --------------------------- Data Carrier Detect CD or DCD 2 ------------------------------ Receive Data RD or RX 3 ---------------------------- Transmitted Data TX or TD 4 ---------------------------- Data Terminal Ready DTR 5 ------------------------------ Signal Ground GND 6 ------------------------------ Data Set Ready DSR 7 ------------------------------ Request To Send RTS 8 ------------------------------ Clear To Send CTS 9 ------------------------------ Ring Indicator RI Transmitted and receive data are referenced from the data device and not the modem. RS-232 SERIAL (COM) PC PORT CONNECTOR DB-25 DB-25 PIN (Male) FUNCTION ABBREVIATION 1 ---------------------------- Chassis/Frame Ground GND 2 ------------------------------ Transmitted Data TX or TD 3 -------------------------------- Receive Data RX or RD 4 ------------------------------ Request To Send RTS 5 ------------------------------- Clear To Send CTS 6 ------------------------------- Data Set Ready DSR 7 ------------------------------- Signal Ground GND 8 ---------------------------- Data Carrier Detect DCD or CD 9 ------------------------- Transmit + (Current loop) TD+ 11 ------------------------ Transmit - (Current Loop) TD- 18 ------------------------- Receive + (Current Loop) RD+ 20 --------------------------- Data Terminal Ready DTR 22 ----------------------------- Ring Indicator RI 25 ------------------------- Receive - (Current Loop) RD- NOTE!! Current loop technology was supported in the PC and XT interfaces. Current loop was discontinued when the AT interface was introduced. Transmitted and receive data are referenced from the data device and not the modem. DB-25 FEMALE SERIAL LOOPBACK PLUG WIRING 2 to 3 Xmit to Rec data 4 to 5 to 22 RTS to CTS to RI 6 to 8 to 20 DSR to CD to DTR DB-9 FEMALE SERIAL LOOPBACK PLUG WIRING 2 to 3 Xmit to Rec data 7 to 8 to 9 RTS to CTS to RI 6 to 1 to 4 DSR to CD to DTR SERIAL PORT LOOPBACK DIAGNOSTIC TESTING RULES When the diagnostic asserts RTS (output) it then tests for the presence of CTS and Ring Indicator (input). If CTS and RI are detected the RTS driver and CTS/RI receivers are considered operational. When DTR is asserted (output) the diagnostic tests for the presence of CD and DSR (input). If CD/DSR are detected the DTR driver and CD/DSR receivers are considered operational. Data is Xmitted and received on the data lines and the data is compared in the diagnostic buffer. If any status's are not detected an error message is displayed. RS-232 SERIAL DB-9 to RS-232 DB-25 ADAPTOR DB-9 PIN (Female) DB-25 PIN (Male) 1 ------------------------------------- 8 DCD 2 ------------------------------------- 3 TXD 3 ------------------------------------- 2 RXD 4 ------------------------------------- 20 DTR 5 ------------------------------------- 7 GND 6 ------------------------------------- 6 DSR 7 ------------------------------------- 4 RTS 8 ------------------------------------- 5 CTS 9 ------------------------------------- 22 RI Use this pin out to adapt between the two serial connector types. RS-232 SERIAL DB-25 to DB-25 NULL MODEM CABLE DB-25 PIN (Female) PC DB-25 PIN (Female) PC 2 ------------------------------------- 3 3 ------------------------------------- 2 7 ------------------------------------- 7 4 ------------------------------------- 5 5 ------------------------------------- 4 6 ------------------------------------- 20 20 ------------------------------------ 6 Note!! All other pins are unused. Use this cable pinout for direct connection between two IBM compatible computers. (LAPLINK) RS-232 SERIAL DB-25 to SERIAL PRINTER NULL MODEM CABLE DB-9 Female PC DB-25 PIN Female PC DB-25 PIN Male printer 2 < RD --------- 3 <------------------------------------- 2 Transmitted data 3 > TD --------->2 -------------------------------------> 3 Receive data 5 < GND -------- 7 <------------------------------------> 7 Ground 8 < CTS -------- 5 ------------------------------------ 6 to 8 to 20 1 to 4 to 6 6 to 8 to 20 4 to 5 DTR/DSR/DCD DTR/DSR/DCD RTS to CTS Note!! Use this cable pinout for direct connection between a PC serial port and a serial printer. The 1/4/6 and 6/8/20 loopbacks are to enable the interface as if a modem was attached. Win95/98 Direct Cable Connection Interlink Cable (Serial port) DB-9---DB-25 (Female) DB-25---DB-9 (Female) 5 7 <------------------------------> 7 5 Gnd-Gnd 3 2 <------------------------------> 3 2 Xmit-Recv data 7 4 <------------------------------> 5 8 RTS-CTS 1&6 6 <------------------------------> 20 4 DSR-DTR 2 3 <------------------------------> 2 3 Recv-Xmit data 8 5 <------------------------------> 4 7 CTS-RTS 4 20<------------------------------> 6 1&6 DTR-DSR Win95/98 Direct Cable Connection Interlink Cable Parallel port (4 bit) DB-25(Male) DB-25(Male) 2 <------------------------------> 15 N/A 3 <------------------------------> 13 N/A 4 <------------------------------> 12 N/A 5 <------------------------------> 10 N/A 6 <------------------------------> 11 N/A 15 <------------------------------> 2 N/A 13 <------------------------------> 3 N/A 12 <------------------------------> 4 N/A 10 <------------------------------> 5 N/A 11 <------------------------------> 6 N/A 25 <------------------------------> 25 Ground-Ground ECP Direct Cable Connection (8 bit) Untested, For the experts only! This pinout was listed for testing two parallel ports and is thought to be correct for running two computers via ECP Direct Cable Connection. DB-25 Male DB-25 Male nStrobe 1 <---------------------------------> 10 nACK Data 0 2 <---------------------------------> 2 Data 0 Data 1 3 <---------------------------------> 3 Data 1 Data 2 4 <---------------------------------> 4 Data 2 Data 3 5 <---------------------------------> 5 Data 3 Data 4 6 <---------------------------------> 6 Data 4 Data 5 7 <---------------------------------> 7 Data 5 Data 6 8 <---------------------------------> 8 Data 6 Data 7 9 <---------------------------------> 9 Data 7 nACK 10 <---------------------------------> 1 nStrobe Busy 11 <---------------------------------> 14 nAutoFwd PError 12 <---------------------------------> 16 nInit Select 13 <---------------------------------> 13,17 Select, nSelectIn nFault 14 <---------------------------------> 17 nSelectIn nAutofwd 15 <---------------------------------> 11 Busy nInit 16 <---------------------------------> 12 PError nSelectIn 17 <---------------------------------> 15 nFault Gnd 18-25 <------------------------------> 18-25 Gnd STANDARD CENTRONICS PARALLEL CABLE DB-25 TO CENTRONICS 36 DB-25 PIN Male (PC) Centronics 36 Male CENTRONICS 36 MALE 1 --------------------------------------> 1 Strobe * CENTRONICS 36 FEMALE 1 CONNECTOR 18 2 <-------------------------------------> 2 Data bit 0 + 18 CONNECTOR 1 \ ------------------ / 3 <-------------------------------------> 3 Data bit 1 + \ ------------------ / \------------------/ 4 <-------------------------------------> 4 Data bit 2 + \------------------/ 19 36 5 <-------------------------------------> 5 Data bit 3 + 36 19 6 <-------------------------------------> 6 Data bit 4+ 7 <-------------------------------------> 7 Data bit 5 + 8 <-------------------------------------> 8 Data bit 6 + 9 <-------------------------------------> 9 Data bit 7 + 10 <------------------------------------- 10 Acknowledge * 11 <------------------------------------- 11 Busy + 12 <------------------------------------- 12 Paper out + 13 <------------------------------------- 13 Select (in) * 14 -------------------------------------> 14 Auto Feed * 15 <------------------------------------- 32 Error * 16 -------------------------------------> 31 Initialize printer * 17 -------------------------------------> 36 Select (out) * 18 thru 25 Gnd 16, 19 thru 30, 33 Ground 15, 17, 18, 34, 35 No connection Note!! * denotes and active low signal. This pin out depicts the newer bi-directional parallel port with input and output capabilities often used with external tape drives and accessory devices. If pins 31 or 32 are grounded on a cable the printer will fail to come ready when attached to the PC. This is common on low cost parallel printer cables. MIDI 5 PIN DIN IN AND OUT CONNECTORS MIDI In MIDI Out pin Signal pin Signal 1 N/C 1 N/C 2 N/C 2 GND 3 N/C 3 N/C 4 Current Src 4 Current Sink 5 Current Sink 5 Current Src IR Module Connector Pin Signal 1 ----------------------------- IRTX 2 ----------------------------- GND 3 ----------------------------- IRRX 4 ----------------------------- N/C 5 ----------------------------- Vcc USB Cable Connector Pin Signal A1 ------------------------------ Vcc A2 ------------------------------ Port0 data- A3 ------------------------------ Port0 data+ A4 ------------------------------ Gnd B1 ------------------------------ Vcc B2 ------------------------------ Port1 data- B3 ------------------------------ Port1 data+ B4 ------------------------------ Gnd 10baseT and 100baseTX crossover cable diagram For direct connection from NIC to NIC with no hub RJ45 Pin# RJ45 pin# TD+ 1 <-----------------------------> 3 RD+ TD- 2 <-----------------------------> 6 RD- RD+ 3 <-----------------------------> 1 TD+ RD- 6 <-----------------------------> 2 TD- The receive data pair (the two wires designated RD) must be a twisted pair, and the transmit data pair (designated TD) must be a twisted pair. When using 10 Megabit (10baseT), category 3, 4 or 5 cable may be used. When using 100 Megabit (100baseTX), the cable must be category 5. 100baseT4 crossover cable diagram For direct connection from NIC to NIC with no hub RJ45 pin# RJ45 pin# TX_D1+ 1 <--------------------------> RX_D2+ 3 TX_D1- 2 <--------------------------> RX_D2- 6 RX_D2+ 3 <--------------------------> TX_D1+ 1 BI_D3+ 4 <--------------------------> BI_D4+ 7 BI_D3- 5 <--------------------------> BI_D4- 8 RX_D2- 6 <--------------------------> TX_D1- 2 BI_D4+ 7 <--------------------------> BI_D3+ 4 BI_D4- 8 <--------------------------> BI_D3- 5 The receive data pair (the two wires designated RX_D2) must be a twisted pair, the transmit data pair (designated TX_D1) must be a twisted pair, the first bi-directional pair (designated BI_D3) must be a twisted pair and the second bi-directional pair (designated BI_D4) must be a twisted pair. Category 3, 4 or 5 cable may be used. Note: These are not IEEE supported configurations and as such, these pinouts are only supported for test purposes. (they do work in practice)