Why would you connect a 15-pin VGA connector to a 9-pin DB connector? [closed]

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.


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.


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