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Usually, the "ports" on the computer are female but this one in specific appears to be a male port. I have never seen one and google images are also causing a confusion from seeing this:

enter image description here

If that's right then I guess the serial plug/connector should be female?

It would also help if the same is cleared up for parallel ports.

DavidPostill
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user12184
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    Ron's right. I would add that the port right next to it is an (S)VGA port. If you see a similar port with only 9 holes, but a female port, then that is likely a video port (pre-VGA, quite possibly using EGA or CGA), not a serial port. – TOOGAM Jan 18 '16 at 23:40
  • Possible duplicate of [Is DB-25 port Serial or Parallel?](http://superuser.com/questions/547374/is-db-25-port-serial-or-parallel) – sawdust Jan 19 '16 at 00:07
  • Dang that is an older PC, it has ps2 ports. – Moab Jan 19 '16 at 00:45
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    @Moab: Really? I have seen those same purple and green ones on modern motherboards as well. – user12184 Jan 19 '16 at 01:00
  • I have not seen them in years, saying that I have not bought a motherboard to build a PC in years. – Moab Jan 19 '16 at 01:26
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    @Moab: Like this one for [example](https://www.asus.com/uk/Motherboards/H81MP_PLUS/) – user12184 Jan 19 '16 at 01:45
  • Be alert when referring to the gender of XLR jacks and sockets as used for professional speaker gear, as used in stage audio or public address systems. I've met multiple musicians who refer to them the wrong way around. – Criggie Jan 19 '16 at 11:06
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    Pins = male. That's pretty much it. – Django Reinhardt Jan 19 '16 at 13:57

1 Answers1

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That is a male serial connector. The big one is a female parallel connector. It used to be common to have both 25-pin serial ports (true RS-232 ports) and 25-pin parallel ports (smaller than the original Centronics parallel ports). The parallel ports were female, and the serial ports were male. This prevented accidentally connecting a cable to the wrong port.

This, of course, was not always the case, but it was a very common way of doing things.

Basil Bourque
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Ron Maupin
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  • Hm, well you said "male serial connector" and "female parallel connector", aren't the connectors 'male' and the ports should be 'female'? – user12184 Jan 18 '16 at 23:38
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    @user12184 -- "connector" and "port" don't necessarily have the meaning that you seem to ascribe. Connectors can be any gender. You may be thinking of (male) "plug" and (female) "socket". – sawdust Jan 18 '16 at 23:44
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    Those are connectors, sometimes called ports. Cables for those connectors will have opposite connectors. Your serial port has a male connector, and the cable for it will have a female connector. For the most part, a male 25- or 9-pin connector on a PC means that it is a serial port, a 25-pin female connector on a PC means it is a parallel port, and a 9-pin female connector is a VGA port. – Ron Maupin Jan 18 '16 at 23:44
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    Answer is IBM PC specific (without mentioning its limitation). Gender of DB-25 for RS-232 more often depended on whether device was DTE or DCE. – sawdust Jan 18 '16 at 23:46
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    @sawdust, I said it was a common way, but it was certainly not limited to IBM. Many computer manufacturers adopted this. I did mention that it was not always the case. – Ron Maupin Jan 18 '16 at 23:49
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    Using a DB25 for a parallel port originated on the IBM PC so that the connector would fit on an adapter bracket. Other computers at the time used the standard Centronics connector, which is too big for the IBM PC bracket. Hence the need for IBM to assign a gender to each type of port. The connectors didn't have the color coding as seen in the photo either. – sawdust Jan 18 '16 at 23:59
  • @RonMaupin: The 9-pin female connector is a VGA port? I see 15 pins for on that blue port which is referred to as VGA. Unless, you mean one of the green or purple one (not sure about them). – user12184 Jan 19 '16 at 00:03
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    @sawdust, yes, and...? I did write that it was smaller than the original Centronics connector. IBM may have originated it, but many manufacturers adopted it, and, as I wrote, it was common. It was only briefly IBM-specific before becoming widely adopted. There is nothing that defines any of this as a standard (other than requiring a 25-pin connector in the RS-232 standard). I gave a generic answer to try to explain what the OP saw in the picture. – Ron Maupin Jan 19 '16 at 00:08
  • @user12184, yes. The original VGA connectors were 9-pin, but have changed over time to the 15-pin connector. "_DE-15 has been conventionally referred to ambiguously as D-sub 15, incorrectly as DB-15 and often as HD-15 (High Density, to distinguish it from the older and less flexible DE-9 connector used on old VGA cards, which has the same E shell size but only two rows of pins)._" [VGA connector](https://en.wikipedia.org/wiki/VGA_connector). – Ron Maupin Jan 19 '16 at 00:11
  • *"but many manufacturers adopted it,"* -- Apparently you're referring to the **PC clone** manufacturers. There's no such gender "standard" for industrial and communications equipment. – sawdust Jan 19 '16 at 00:22
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    @sawdust, yes, PC clone manufacturers among others. I had a project to replace a couple of large, older DG minicomputers with a much smaller, newer, mini-file cabinet sized DG minicomputer. I had to chop off and replace the 48 terminal cable connectors because the older minicomputers had 25-pin female connectors, but the newer minicomputer had 25-pin female connectors, just like the PCs of the time. I have seen various PBX systems which used 25- or 9- pin male serial connectors. All I wrote is that it was common; I didn't write that it was ubiquitous. – Ron Maupin Jan 19 '16 at 00:33