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Scancode Bit 0Keyboard Connectors
- Updated 20th March 2024
This page covers various keyboard-related physical interfaces such as connectors/plugs, modular cable sockets, PCB header pins, and cable wire colour coding. General connectors and cable sockets are organised into sections containing just that specific type of plug or socket, whereas the rest are organised into sections dedicated to their host keyboard.
Contents
Plug & socket identificationDIN/Mini-DIN socket pinoutsModular-style socket pinoutsSDL socket pinoutsIDC-style socket pinoutsD-subminiature socket pinoutsModular cable end-to-end mappings532X Datamaster Model F5150/5155/5160 XT Model F5291/5292 Model FType II 104-key, 122-key and 5170 AT Model F & 122-key Model MLexmark or Unicomp 101/102-key fixed cable Model MP/N 69H8533 5535-ZPP Numeric KeypadP/N 40N6377 4820 SurePoint KeypadSources
Note
The introduction dates given are approximate for their introduction on IBM and family keyboards, not when the connector itself was introduced in general.
DB-25 male plug
A screwable D-subminiature plug used by IBM 3270 and 5280 compatible terminal keyboards that transmitted scancodes in parallelised bits and had a clicker assembly or a buzzer. This includes the 327X-75, 327X-87 and 327X-OC type Model Bs, all IBM 5280-series Model Bs, and Type 1 104-key Model F Converged Keyboards. The amount of pins actually present could vary between exact keyboard series.
DA-15 male plug
A screwable D-subminiature plug used by various IBM terminal keyboards such as 3101, 525X-82, 6580 type Model Bs and 31XX-75 and 31XX-87 type Model Fs that transmitted scancodes in serialised bits but required more pins than later typical DIN plugs provided (ie, for specific command lines, a clicker assembly or a buzzer). It was also used by IBM 5291 Model 2 Model F keyboards for a special host-drives-capsense connectivity.
5-pin 180-degree DIN male plug
The standard DIN plug for all XT and AT keyboards. Only 4 pins are needed for a standard AT-compatible keyboard connection, but XT-compatible keyboards may use the remaining pin as a RESET pin.
5-pin 240-degree DIN male plug (w/ metal jacket)
The DIN plug used by IBM 3179, 3180, 3193, 3205 & 3290 Model 2 terminal and 3270 PC keyboards (Type 2 104-key and most 122-key Model F Converged Keyboards and Type 1 122-key Model M Converged Keyboards). This was the first of two compatible DIN-5-240 plugs, with a straight metal screwable jacket.
DE-9 male plug
A screwable D-subminiature plug used for some keyboards such as IBM 4704-family keyboards and some TEMPESTed Model F variants. It's also used an interface for RS232 serial and thus also used by various early PC mice.
6-pin Modular male plug
The 6-pin modular-style plug used by IBM 5155 Portable Personal Computer and 3153 InfoWindow keyboards. It's the same modular plug used for RJ-11, RJ-14 and RJ-25 (but they're not used in the same way thus are incompatible) and sometimes erronously referred to as any of these.
6-pin SDL female port
A modular cable socket used by many Model M keyboard variants. It always supports a AT-compatible keyboard connection but may also support a PS/2 or RS232 serial mouse connection (eg, for Models M4-1, M5-1 and M5-2) or a speaker connection (for RS/6000 keyboards) as well.
8-pin SDL female port
A modular cable socket used by many IBM POS keyboards. It's been used for an RS485 SIO keyboard connection (IBM 4680 and pre-USB 4690 series) and PS/2 keyboard and mouse connections (Model M-e PS/2 ANPOS and CANPOS Keyboards).
5-pin 240-degree DIN male plug (w/ plastic jacket)
The DIN plug used by IBM 3161, 3162, 3163, 3164, 3191, 3192, 3196, 3197 and 3206 terminal keyboards (most pre-1987 Model M Enhanced Terminal Keyboards and Type 2 122-key Model M Converged Keyboards). This was the second of two compatible DIN-5-240 plugs, with a right-angle plastic jacket.
6-pin Mini-DIN male plug
The standard mini-DIN plug for all PS/2 keyboards. Only 4 pins are needed for a standard AT-compatible keyboard connection, so versions of the plug lacking two of the pins are known. Some IBM laptop numeric keypads and POS keyboards may use all the pins to include a PS/2 mouse (passthrough or otherwise) connection as well. IBM RS/6000 keyboards may use the remaining 2 pins for a speaker connection.
8-pin Modular male plug
The 8-pin modular-style plug used by IBM 3151, 347X InfoWindow and 348X InfoWindow II terminal keyboards (most 1987-onwards Model M Enhanced Terminal Keyboards and Type 3 122-key Model M Converged Keyboards). It's the same modular plug used for RJ-45 and ethernet (but they're not used in the same way and thus are incompatible) and sometimes erroneously referred to as either.
8-pin Mini-DIN male plug
The mini-DIN plug used by the Apple Newton MessagePad Keyboard (X0044) for a serial connection (despite also being one of the plugs for Apple LocalTalk, they're not used in the same way thus are incompatible).
Type A USB male plug
The standard host-side plug for USB devices including keyboards. The plastic part inside may be coloured white to indicate the device is USB 1.x compatible, black for USB 2.0 and blue for USB 3.x.
4-pin (4x1) IDC-style male plug
The keyboard-side plug from modular cables used for IBM USB RPOS and ANPOS w/ IPD keyboards. It's essentially a standard 2.54mm-pitch connector with a jacket to allow it to secure into a socket and levers for it to be released.
12V PoweredUSB male plug
A specialised USB plug that extends the standard Type A plug with extra pins for increased power delievery. It was used by some modular cables for USB IBM and TGCS POS keyboards.
12-pin (6x2) IDC-style male plug
The keyboard-side plug from modular cables used for IBM MPOS keyboards. It's essentially a standard 2.54mm-pitch connector with a jacket to allow it to secure into a socket and a lever for it to be released.
6-pin staggered Pogo USB male interface
A contact-based USB interface used by Lenovo ThinkPad X1 Tablet Thin Keyboards Gen 1 (TP00082K1) and 2 (TP00082K3). For a secure connection, the keyboard must be magnetically attached to its host tablet.
6-pin straight Pogo USB male interface
A contact-based USB interface used by the Lenovo ThinkPad X1 Tablet Gen 3 Thin Keyboard (TP00089K1). For a secure connection, the keyboard must be magnetically attached to its host tablet.
Type A Lockable USB female port
A modular cable socket used by the Unicomp Mini Model M. It's designed to clamp on an inserted cable to provide mechanical security and can be released by pushing the tab above the port.
XT with reset line 180° DIN
XT/AT 180° DIN
Terminal 240° DIN
PS/2 6-pin mini-DIN
Keyboard & mouse combo IBM keypad PS/2-like 6-pin mini-DIN
Apple Newton MessagePad X0044 8-pin mini-DIN
5155 XT modular-6P5C ("RJ-25" like)
Terminal modular-8P5C ("RJ-45" like)
Terminal Model M2 modular-6P4C ("RJ-14" like)
Device-side
Standard Model M SDL
RS/6000 Model M /w speaker SDL
Keyboard & mouse combo Model M4-1/M5-1/M5-2 SDL
4680 POS & Retail POS Model M7/M8/M9/M11 RS485 SDL
Retail POS Model M7/M8/M9/M11 PS/2 SDL (single plug cable)
Pre-Modular POS Model M-e PS/2 ANPOS/CANPOS w/ Integrated Pointing Device SDL (dual plug cable)
IBM Base Keyboard (3276/3278/3279) DB-25
IBM 5251/5252 DB-25
IBM 5291-2/5292 DA-15
IBM Base Keyboard (3104/3178) DA-15
Type 1 104-key IBM Converged Keyboard (3290-1/5085) DB-25
Modular cable end-to-end mappings
These tables describe the pin translation between one end of a modular keyboard cable to another (in all present cases, a form of SDL to PS/2).
| SDL end pin | PS/2 end pin | PS/2 end function |
|---|---|---|
| 1 | - | N/C |
| 2 | 1 | DATA |
| 3 | 3 | GND |
| 4 | 5 | CLOCK |
| 5 | 4 | +5V |
| 6 | - | N/C |
6-pin SDL to dual PS/2
The Y-split PS/2 cables Model Ms that have an SDL socket and an integrated pointing device such as the Models M4-1, M5-1 and M5-2 use.
| SDL end pin | PS/2 plug | PS/2 end pin | PS/2 end function |
|---|---|---|---|
| 1 | Mouse | 5 | CLOCK (mouse) |
| 2 | Keyboard | 1 | DATA (keyboard) |
| 3 | Both | 3 | GND |
| 4 | Keyboard | 5 | CLOCK (keyboard) |
| 5 | Both | 4 | +5V |
| 6 | Mouse | 1 | DATA (mouse) |
8-pin SDL to PS/2
The single plug PS/2 cables that the IBM PS/2 ANPOS Keyboard w/ IPD and IBM CANPOS Keyboard use.
| SDL end pin | PS/2 end pin | PS/2 end function |
|---|---|---|
| 1 | 5 | CLOCK |
| 2 | 3 | GND |
| 3 | 4 | +5V |
| 4 | 2 | - |
| 5 | 6 | - |
| 6 | 3 | GND |
| 7 | 4 | +5V |
| 8 | 1 | DATA |
532X Datamaster Model F
The 5322 keyboard assembly is the integrated keyboard for the original desk-top IBM 5322 System/23 Datamaster, whereas the 5324 keyboard module is the discrete (separated) keyboard for the slightly later floor-top 5234 Datamaster. The Keyboard Adapter Card refers to a daughterboard present inside the latter. The 5324 keyboard-to-motherboard connection has two cables - the external cable between the Keyboard Adapter Card and the connector on the outside of the computer, and the internal cable from that connector to the motherboard.
5322/5324 assembly header5322 motherboard header5324 Keyboard Adapter Card header5324 motherboard header
5322/5324 assembly header
This header is present on both keyboards' main PCB. On 5322 keyboard assemblies, this header is used by a cable that goes straight to the host Datamaster's motherboard. For 5324 keyboard modules, the Keyboard Adapter Card is directly connected to this header.
2
+5V3
Scancode Bit 14
GND5
Scancode Bit 26
Scancode Bit 37
Scancode Bit 48
Scancode Bit 59
Data Strobe10
Scancode Bit 611
X12
Program Reset13
14
Data Strobe5322 motherboard header
This header is on the 5322's motherboard (CPU planar board) and is the other end of the cable between it and the keyboard assembly.
B1
Program ResetB2
B3
Data StrobeB4
Scancode Bit 6B5
Scancode Bit 5B6
Scancode Bit 4B7
Scancode Bit 3B8
Scancode Bit 2A1
XA2
Delay StrobeA3
XA4
XA5
Scancode Bit 0A6
+5VA7
Scancode Bit 1A8
GND5324 Keyboard Adapter Card header
This header is on the 5324 keyboard module's Keyboard Adapter Card for the external cable. The "Return" pins appear to be connected to Ground when they reach the internal cable. The functions of A15, A16, B15 and B16 (if any were intended) are unlabelled in IBM's documentation.
B1
Data StrobeB2
B3
Scancode Bit 6B4
Scancode Bit 5B5
Scancode Bit 4B6
Scancode Bit 3B7
Scancode Bit 2B8
Scancode Bit 1B9
Scancode Bit 0B10
XB11
Delay StrobeB12
Program ResetB13
XB14
+12VB15
B16
A1
ReturnA2
ReturnA3
ReturnA4
ReturnA5
ReturnA6
ReturnA7
ReturnA8
ReturnA9
ReturnA10
ReturnA11
ReturnA12
ReturnA13
ReturnA14
ReturnA15
A16
5324 motherboard header
This header is on the 5324's motherboard (CPU planar board) and is the other end of the internal cable between it and the outside connector for hooking up the external cable.
B1
Program ResetB2
B3
Data StrobeB4
Scancode Bit 6B5
Scancode Bit 5B6
Scancode Bit 4B7
Scancode Bit 3B8
Scancode Bit 2A1
XA2
Delay StrobeA3
+12VA4
XA5
Scancode Bit 0A6
XA7
Scancode Bit 1A8
GND5150/5155/5160 XT Model F
The IBM Personal Computer Keyboard (aka, the Model F/XT) exist in two electrical variaties - Types I and II. Type I are typically very early examples that include a reset pin, have a metal jacketed DIN plug and have a two-board internal controller. Type IIs lack a reset pin, have a plastic jacketed DIN plug and have a single controller card. Type IIs seem to be far more common than Type I. All 5155 Portable PC Keyboards are based on Type II.
Type I mainboard header (with reset pin)Type II mainboard header (without reset pin)Type II Wire colour coding key
| Colour | Header | Plug (180-degree DIN) |
|---|---|---|
| Brown | +5V | 5 |
| Red | GND | 4 |
| White | Data | 2 |
| Black | Clock | 1 |
| Silver | N/A (grounding screw) | - |
Mainboard header
Orientation: position the host board as such that this header is to the left side of said board.
10
Count 649
Count 328
Count 167
X6
X5
X4
Count 83
Count 42
1
Count 211
Key Down12
GND13
+5V14
X15
X16
X17
Count 118
GND19
Strobe20
GNDHeader to Soarer's Controller mapping
Note that this keyboard's header pinout has three GND pins - you only need to use one of the pins and you're free to use any one of them.
| Header | Teensy 2.0 | Arduino Micro | Pro Micro |
|---|---|---|---|
| Count 2 | B1 | SCK | 15 |
| Count 4 | B2 | MOSI | 16 |
| Count 8 | B3 | MISO | 14 |
| Count 16 | B4 | D8 | 8 |
| Count 32 | B5 | D9 | 9 |
| Count 64 | B6 | D10 | 10 |
| Key Down | D0 | D3 (SCL) | 3 |
| GND | GND | GND | GND |
| +5V | VCC | +5V | VCC |
| Count 1 | B0 | RXLED | RXLED |
| Strobe | D1 | D2 (SDA) | 2 |
Note
The cable header pins may be apart of a much larger array of pins. If this is the case, the missing pin indicated below can be used to recognise where to connect the cable or converter solution.
X
+5V
Clock
GND
Data
| Colour | Header | Plug (PS/2) |
|---|---|---|
| Black | +5V | 4 |
| Red | Clock | 5 |
| White | GND | 3 |
| Yellow | Data | 1 |
| Silver | N/A (grounding screw) | - |
Mainboard header
Key: K - keyboard pin, M - mouse pin
1
X2
X3
X4
1: DATA (M)5
2: DATA (K)6
3: GND7
4: +5V8
5: CLOCK (M)9
6: CLOCK (K)10
PE| Colour | Header | Plug (PS/2) |
|---|---|---|
| Yellow | 4 | 1 |
| Green | 5 | 2 |
| Blue | 6 | 3 |
| Red | 7 | 4 |
| White | 8 | 5 |
| Black | 9 | 6 |
| Black | 10 | PE |
- JP2: 5-pin (4 used) membrane rows
- JP3: 9-pin membrane columns
- JP4: 10-pin (9 used) magnetic stripe reader
Note: JP4 silkscreening has 0 to 1 as its range, which for the sake of readability, I've replaced with a scale of 1 to 10 respectively going forward.
Mainboard header
Orientation: use silk-screening on the PCB itself or the absent pin 17 as reference.
Note: pin 15 is shared between JP4 pin 1 and magnetic stripe reader shield (SHD).
1
9 (JP3)3
7 (JP3)5
4 (JP3)7
6 (JP3)9
1 (JP3)11
3 (JP2)13
2 (JP2)15
1 (JP4) & SHD17
19
5 (JP4)21
7 (JP4)23
9 (JP4)2
8 (JP3)4
3 (JP3)6
5 (JP3)8
2 (JP3)10
1 (JP3)12
4 (JP2)14
1 (JP2)16
2 (JP4)18
4 (JP4)20
6 (JP4)22
8 (JP4)24
10 (JP4)| Colour | JP4 pin |
|---|---|
| Black | 1 |
| Brown | 2 |
| Orange | 4 |
| Yellow | 5 |
| Green | 6 |
| Blue | 7 |
| Purple | 8 |
| Grey | 9 |
| White | 10 |
Ardent Tool - pinout for RS/6000 Model M SDL diagramIBM SY34-0171-0 - 5322 information (PDF page 82 onwards)IBM SY34-0241-1 - 5324 information (PDF page 82 onwards)KbdBabel - IBM 5251/5252 pinoutSandy55 - pinout for Terminal Model M2 modular-6P4C diagramsnuci - info on the differences between Type I and II Model F/XTsTheMK#1822 - PS/2 pin positions for Modular POS Model M-e 6x2 IDC diagram
