Anyone have any idea what one would connect with this cable? Going from a 15-pin VGA connector to a DB9 is very odd.

1.5M VGA HD15 Male to DB9 Pin Male Adapter Cable White

The reason I ask is that in an effort to get some hardware that required a serial connection for use up and running at a remote site, the local support person went our and found one of these things. Obviously plugging the VGA port into a serial port is not going to work but they must have seen too many movies where folks just plugs things in and all is well. In this case, the hardware was made... non-functional.

  • We should have an "idle" tag for this type of question like slashdot. :)
    – Yitzchak
    Aug 17 '11 at 16:52

I have two pieces of equipment that use DB9 to HD15 adapter cables:

  1. RS-232: an NEC 6PGplus CRT front projector has a RS-232 serial port that uses a female HD-15 connector. The casual observer usually thinks this is a VGA input, but it's not; video has to be input by RGBHV on five BNC inputs.

  2. VGA: the original NEC Multisync computer monitor used a DB9 connector (for CGA and EGA connections). To connect to a VGA adapter, a short DB9 to HD15 cable is needed.


Cables with standard (IEEE) ends can be used for many other things other than the one thing an online store might think it's for.

RS-232 interfaces for example.

One thing that does need this cable and if video/VGA related, is that some of the older Sony Multiscan monitors could do VGA, but they had a weird DB9 connector instead of the more traditional HD15.

  • Of course. See the added explanation as to why this question came up. There were many baffled folks here at the office when we were told what the person did with the cable.
    – dwj
    Aug 17 '11 at 18:28
  • 1
    The early VGA monitors often had both digital and analog connectors, analog being 15-pin, digital 9-pin. CGA and EGA, and some modes of VGA, worked on digital connection, but to get full 24-bit VGA colorspace you needed the 15-pin analog connection.
    – Zds
    Aug 17 '11 at 20:15

I suppose there is an outside chance it's something to do with the archaic CGA connections but so far as I'm aware you can't connect them to a VGA card.

EDIT: After a poke around I think it's more likely the VGA bit is complete cobblers it's more likely to be one of these modem cables

  • The modem connection is very interesting. In the modern day, someone sees 15 pins and says "oh, VGA" and that's what goes in the summary for the part on Amazon.
    – dwj
    Aug 17 '11 at 18:27
  • I have to admin even the modem connection was new to me, I've never seen the three row connector on a serial connection although I've seen two row 25 pin connections.
    – Col
    Aug 17 '11 at 18:48
  • The cables were common for going the other direction (hooking CGA/EGA cards up to VGA monitors) for awhile, but that's just odd to see a new cable on Amazon... Feb 24 '16 at 20:15

Older palm pilot models (think M100) connected to computers via DB9. This could have been used to connect such a device to a machine where the DB9 port was already taken, or to connect it to the computer's graphics card as a display, though I have absolutely no clue why anyone would do that.

Not the answer you're looking for? Browse other questions tagged or ask your own question.