One cable type absent from this list is the USB cable. I don't have access to one of these cables so I have not had an opportunity to examine it. My understanding is that it is an "active" cable, containing USB-to-PS/2 conversion circuitry, so a simple pinout may not be sufficient to duplicate it.
Console Cables (KVM to keyboard/mouse/display)
A user has reported success using pinout #2 as a console cable to connect the master
keyboard, mouse, and display to the KVM by simply using female connectors in place of male. This technique may
also work for the other cable types. Please let me know if you have success doing this.
Pinout 1: The DB25M connector itself
The table below shows the function of each pin on the DB25M connector. Use this information if you need to build a custom cable other than the five listed above. Note that some pins serve multiple functions depending upon what system that particular port is configured for. The video and GND pins always serve the same function regardless of mode setting.| Pin | Function | Pin | Function |
|---|---|---|---|
| 1 | GND | 14 | Red Video |
| 2 | GND | 15 | Green Video |
| 3 | GND | 16 | Blue Video |
| 4 | GND | 17 | |
| 5 | HSYNC Sun CSYNC | 18 | |
| 6 | VSYNC | 19 | |
| 7 | ADB Data(1) PC Keyboard CLK Sun Keyboard In(2) | 20 | Apple CSYNC |
| 8 | ADB Data(1) PC Keyboard DATA INV Sun Keyboard Out(3) | 21 | |
| 9 | ADB Power-On PS/2 Mouse CLK | 22 | GND |
| 10 | ADB Data(1) PS/2 Mouse DATA | 23 | GND |
| 11 | Power (+5VDC) | 24 | |
| 12 | Serial Mouse TXD Sun Mouse Out | 25 | Serial Mouse RXD Sun Keyboard In(2) |
| 13 | Serial Mouse RTS Sun Keyboard Out |
* Directions such as Rx, Tx, In, and Out are switchbox relative computer.
* Any pins not mentioned are unconnected (N/C).
(1) All three ADB Data pins are tied together on Apple ADB cables.
(2) Both pins are tied together on Sun cables.
(3) The KVM provides Sun keyboard output here using positive logic. Sun systems use negative logic so this signal is the opposite of what must be fed to the Sun. An external inverter contained in the cable recitifies the situation. See Pinout 6 for details.
Pinout 2: PC PS/2 keyboard, PS/2 mouse, and HD-DB15 video cable
This cable will connect a BlackBox KVM to a standard PC using PS/2 Keyboard and Mouse connectors and a HD-DB15 SVGA video connector.Tested On: Several PC clones with varying motherboards and video cards. All worked without a problem.
| KVM DB25 Male  |
Dir |
Keyboard MiniDIN-6 Male  |
Mouse MiniDIN-6 Male |
Video HD-DB15 Male  |
Function |
|---|---|---|---|---|---|
| 1 |  | 4, 5 | GND | ||
| 2 | | 6 | GND | ||
| 3 | | 7 | GND | ||
| 4 | | 8 | GND | ||
| 5 |  | 13 | HSYNC | ||
| 6 | | 14 | VSYNC | ||
| 7 |  | 5 | KBD CLK | ||
| 8 | | 1 | KBD DATA | ||
| 9 | | 5 | MSE CLK | ||
| 10 | | 1 | MSE DATA | ||
| 11 |  | 4 | 4 | +5VDC | |
| 14 | | 1 | RED | ||
| 15 | | 2 | GREEN | ||
| 16 | | 3 | BLUE | ||
| 22 | | 10, 11 | GND | ||
| 23 | | 3 | 3 | GND |
The GND signals can be connected to any of the 6 GND pins on the DB25M. I've depicted them in no particular order. Any pins not mentioned are unconnected (N/C).
Pinout 3: PC XT keyboard, Serial mouse, and HD-DB15 video cable
This cable will connect a BlackBox KVM to a standard PC using an XT Keyboard, Serial Mouse, and a HD-DB15 SVGA video connector.Tested On: Currently untested.
| KVM DB25 Male |
Dir |
Keyboard DIN-5 Male  |
Mouse DB9 Female  |
Video HD-DB15 Male |
Function |
|---|---|---|---|---|---|
| 1 | | 4, 5 | GND | ||
| 2 | | 6 | GND | ||
| 3 | | 7 | GND | ||
| 4 | | 8 | GND | ||
| 5 | | 13 | HSYNC | ||
| 6 | | 14 | VSYNC | ||
| 7 | | 1 | KBD CLK | ||
| 8 | | 2 | KBD DATA | ||
| 11 | | 5 | +5VDC | ||
| 12 | | 2 | MSE RXD | ||
| 13 | | 7 | MSE RTS | ||
| 14 | | 1 | RED | ||
| 15 | | 2 | GREEN | ||
| 16 | | 3 | BLUE | ||
| 22 | | 10, 11 | GND | ||
| 23 | | 4 | 5 | GND | |
| 25 | | 3 | MSE TXD |
The GND signals can be connected to any of the 6 GND pins on the DB25M. I've depicted them in no particular order. Any pins not mentioned are unconnected (N/C).
Pinout 4: Apple ADB keyboard and mouse, and HD-DB15 video cable
This cable will connect a BlackBox KVM to a Apple computer using an ADB Keyboard and Mouse, and a HD-DB15 SVGA video connector.Tested On: Currently untested. The pinout was determined from an assembled (i.e., not moulded) cable so I'm fairly confident it is correct and the real cable does not harbor any hidden electronics.
| KVM DB25 Male |
Dir |
Keyboard/Mouse MiniDIN-4 Male  |
Video HD-DB15 Male |
Function |
|---|---|---|---|---|
| 1 | | 4, 5 | GND | |
| 2 | | 6 | GND | |
| 3 | | 7 | GND | |
| 4 | | 8 | GND | |
| 5 | | 13 | HSYNC | |
| 6 | | 14 | VSYNC | |
| 7 | | 1 | ADB DATA | |
| 8 | | 1 | ADB DATA | |
| 9 | | 2 | ADB PWRON | |
| 10 | | 1 | ADB DATA | |
| 11 | | 3 | +5VDC | |
| 14 | | 1 | RED | |
| 15 | | 2 | GREEN | |
| 16 | | 3 | BLUE | |
| 22 | | 10, 11 | GND | |
| 23 | | 4 | GND |
The GND signals can be connected to any of the 6 GND pins on the DB25M. I've depicted them in no particular order. Any pins not mentioned are unconnected (N/C).
Pinout 5: Apple ADB keyboard and mouse, and DB15 video cable
This cable will connect a BlackBox KVM to a Apple computer using an ADB Keyboard and Mouse, and a DB15 VGA video connector.Tested On: Currently untested. The pinout was determined from an assembled (i.e., not moulded) cable so I'm fairly confident it is correct and the real cable does not harbor any hidden electronics.
| KVM DB25 Male |
Dir |
Keyboard/Mouse MiniDIN-4 Male |
Video DB15 Male  |
Function |
|---|---|---|---|---|
| 1 | | 1 | GND | |
| 2 | | 6 | GND | |
| 3 | | 11 | GND | |
| 4 | | 4,13 | GND | |
| 5 | | 15 | HSYNC | |
| 6 | | 12 | VSYNC | |
| 7 | | 1 | ADB DATA | |
| 8 | | 1 | ADB DATA | |
| 9 | | 2 | ADB PWRON | |
| 10 | | 1 | ADB DATA | |
| 11 | | 3 | +5VDC | |
| 14 | | 2 | RED | |
| 15 | | 5 | GREEN | |
| 16 | | 9 | BLUE | |
| 20 | | 3 | CSYNC | |
| 22 | | 14 | GND | |
| 23 | | 4 | GND |
The GND signals can be connected to any of the 6 GND pins on the DB25M. I've depicted them here exactly how they are wired on BlackBox's cables. Any pins not mentioned are unconnected (N/C).
Pinout 6: Sun Type 4, 5 keyboard and mouse, and 13W3 video cable
This cable will connect a BlackBox KVM to a Sun computer using a Type 4 or Type 5 Keyboard and Mouse, and a 13W3 SVGA video connector. It is more complex than the other cables because it requires some active electronics (an inverter) to be wired onto the DB25M. I don't know why the KVM switchbox itself does not do the inversion instead of driving up the cost and complexity of the cable.Tested On: Sun Sparc 5 with TCX (AFX port) framebuffer and also on an Ultra 1 with a CG6 framebuffer. I used the discrete inverter shown below; I have not tested with a prepackaged TTL inverter chip.
| KVM DB25 Male |
Dir |
Keyboard/Mouse MiniDIN-8 Male  |
Video 13W3 Male  |
Function |
|---|---|---|---|---|
| 1 | | 10 | GND | |
| 2 | | A1-GND | GND | |
| 3 | | A2-GND | GND | |
| 4 | | A3-GND | GND | |
| 5 | | 5 | CSYNC | |
| 7* | | 5 | KBD OUT | |
| 8# | | INV to 6 | KBD IN (INV) | |
| 11 | | 3, 8 | +5VDC | |
| 12 | | 4 | MSE IN | |
| 13# | | 6 | KBD IN | |
| 14 | | R (A1) | RED | |
| 15 | | G (A2) | GREEN | |
| 16 | | B (A3) | BLUE | |
| 22 | | 1 | GND | |
| 23 | | 2 | GND | |
| 25* | | 5 | KBD OUT |
# DB25 pin 8 connects through an inverter to MiniDIN-8 pin 6, which also connects to DB25 pin 13. For the inverter, you can use a TTL logic part such as the 74LS04 or build your own using a transistor and two resistors as shown below. The discrete version will be a bit smaller, but prepackaged is more convenient.
Discrete Inverter:
Prepackaged Inverter:
The GND signals can be connected to any of the 6 GND pins on the DB25M. I've depicted them in no particular order. Any pins not mentioned are unconnected (N/C).
Pinout 7: SGI PS/2 keyboard, PS/2 mouse, and 13W3 video cable
This cable will connect a BlackBox KVM to an SGI machine using a PS/2 keyboard and mouse, and 13W3 video connector. The keyboard and mouse connections are identical to those on a PC cable. The 13W3 video pinout is the same as a Sun cable except the sync signals are not connected (SGIs typically use sync-on-green).Tested On: SGI Indy R4000 with Indy 8-bit video
| KVM DB25 Male |
Dir |
Keyboard MiniDIN-6 Male |
Mouse MiniDIN-6 Male |
Video 13W3 Male |
Function |
|---|---|---|---|---|---|
| 1 | | A1-GND | GND | ||
| 2 | | A2-GND | GND | ||
| 3 | | A3-GND | GND | ||
| 7 | | 5 | KBD CLK | ||
| 8 | | 1 | KBD DATA | ||
| 9 | | 5 | MSE CLK | ||
| 10 | | 1 | MSE DATA | ||
| 11 | | 4 | 4 | +5VDC | |
| 14 | | R (A1) | RED | ||
| 15 | | G (A2) | GREEN | ||
| 16 | | B (A3) | BLUE | ||
| 22 | | 3 | GND | ||
| 23 | | 3 | GND |
The GND signals can be connected to any of the 6 GND pins on the DB25M. I've depicted them in no particular order. Any pins not mentioned are unconnected (N/C).
Changelog
7/4/2003: Initial revision.7/12/2003: Updated Sun cable description to show required inverter. Updated top-level DB25M pinout to reflect the Sun inverter. Changed signal direction names to be relative to the KVM switchbox, not the computer.
7/27/2003: Added SGI cable pinout. Added "Tested On" section to all cables.
8/29/2004: Added success report for using pinout #2 as a console cable.
Feel free to send questions and comments to me at akropel1@rochester.rr.com.
This page is not associated with or endorsed by BlackBox Corporation in any way.
This page is not associated with or endorsed by Rose Electronics in any way.
Copyright (c) 2003 by Adam Kropelin, All Rights Reserved.