Why do we still have PS/2 ports on motherboards?

Discussion in 'Motherboards' started by The Neo Zero, Apr 9, 2018.

  1. The Neo Zero

    The Neo Zero [H]ard|Gawd

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    Does anyone even use or have a device that connects to PS/2 ports anymore?
    I noticed this on the Gigabyte Aorus X399 Designare EX

    1521197640843huzhoqh_1_19_l.jpg
     
  2. Neapolitan6th

    Neapolitan6th Limp Gawd

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    Haha its a feature. I'm not really in the competitive gaming scene, but isn't PS/2 technically the superior low latency connection as it doesn't have to go through the chipset? (I could be speaking nonsense here, can't remember where I may have heard that)
     
    Last edited: Apr 10, 2018
  3. Master_shake_

    Master_shake_ [H]ardness Supreme

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    because sometimes spamming f2 or delete on a usb keyboard achieves nothing but frustration.
     
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  4. N4CR

    N4CR 2[H]4U

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    What Master_shake_ said. I remember in the older days USB wouldn't be supported by BIOS and some OS until you had drivers... so they put the PS2 stuff (and USB>PS2 adaptors in) just in case it seems.
     
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  5. Zepher

    Zepher [H]ipster Replacement

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    It could be useful when Windows 10 decides to disable every USB port on your PC.

    windows-10-usb-error.jpg
     
  6. Denpepe

    Denpepe Limp Gawd

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    PS/2 keyboards do have a lower latency, they also better for Nkey rollover (handy for gaming or really fast typists) and as others mentioned can work when USB wont for some reason as they are interrupt based.
     
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  7. sirmonkey1985

    sirmonkey1985 [H]ard|DCer of the Month - July 2010

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    old school keyboards are still really popular, also ps/2 bypasses fast boot options in bios since ps/2 is instant on if you still want to get into bios while leaving fast boot turned on.

    also another example, my work which just replaced all their computers... still uses ps/2 keyboards and mouses from the early 2000's so yeah that's another reason, lol.
     
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  8. FlawleZ

    FlawleZ Limp Gawd

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    I love having PS2 availability on modern boards. Some BIOSes are tricky getting into with a USB keyboard or refuse to accept input from then at all at times. Additionally, EXTREME overclockers use PS2 as you frequently lose USB when pushing motherboards to their limits.
     
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  9. Aluminum

    Aluminum Limp Gawd

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    PS/2 is objectively superior to usb for keyboards.

    New usb versions won't change this fact unless they actually make a new dedicated HID hardware interface/profile for inputs and convince every single OS/platform to support it. I put the odds of that happening somewhere around when pigs fly, so not impossible (genetic engineering!) but yeah.

    Even though old bios mode is ssssslowly going away with pure UEFI going mainstream, PS/2 support is still in there. So expect it to keep on trucking at least a few more decades.
     
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  10. Unabomber

    Unabomber [H]ardness Supreme

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    Damn right I still use a PS/2 keyboard. My IBM M-class keyboards were built in early 90's, and I absolutely refuse to let go of them for my computers. These are solidly built, have seen me through college, graduate school, my postdoctoral fellowship, and my current job of 15.5 years.

    I realize that most people simply use their flimsy USB keyboards that come pre-packaged with their Dell computers, but I hate the feel of them. I also find that I type my usual 100 words per minute with less accuracy using one of those "modern" keyboards.
     
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  11. Aluminum

    Aluminum Limp Gawd

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    I like M's for self defense...I mean typing but the PS/2 superiority has nothing to do with the quality of the keyboard, it is the interface design. USB made some shortcuts and assumptions along with the HID profile itself that make it inferior in various ways, though obviously not cost. Goes hand in hand with $0.50 bundled keyboards for sure.

    BTW there are plenty of modern mechanicals that outdo the M1 tank...keyboard also without alienating those around you too. You can also build your own personal custom modern tank or become one with the cup rubber ;)
     
  12. sanders4617

    sanders4617 [H]Lite

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    I still used a PS2 keyboard up until a week ago. Glad all my mobo's have had it for sure.
     
  13. GiGaBiTe

    GiGaBiTe Limp Gawd

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    Its not really correct to compare PS/2 and USB in terms of latency, because that's not what's going on.

    What laymen interpret as low latency on PS/2 keyboards and mice is the fact that they have assigned dedicated hardware interrupts. Out of the 16 hardware interrupts available (0-15, 0 given the most priority), the PS/2 keyboard is 1 and the mouse is 12. This means that every time there's an input on either the keyboard or mouse, an interrupt is fired and the host CPU must stop everything else and deal with the interrupt before continuing. Since interrupts are dealt with in order of low to high, the PS/2 keyboard is one of the highest priority devices in the system, only being behind the system timer. The mouse has a few things ahead of it (serial, parallel, RTC, video) but is right up there with the keyboard if one or more of these aren't used. If you use a serial mouse, you have an even higher priority.

    Input latency is basically non existent here because interrupts are measured in nanoseconds.

    USB on the other hand uses software to poll the device (usually via a driver.) Input latency becomes an issue because pretty much everything can affect the polling cycle time. High CPU load can cause USB HID devices to start acting erratically, such as the mouse teleporting around the screen or the keyboard missing key inputs. Other malfunctioning USB devices (most commonly misbehaving flash drives) can also bring down the entire USB subsystem and cause all USB devices to stop working until the offending device is removed, and sometimes requiring a system restart.

    Input lag on USB devices can be measured in milliseconds or higher.

    USB trades hardware interrupts of PS/2 for convenience. PS/2 devices were never designed to be hot plugged, doing so can potentially cause damage to the host system. The plugs aren't rated for high numbers of insertion cycles, and the plug itself is fragile. I can't tell you how many careless users I had to do plug repair on back in the 90s / early 2000s from snapping the key off and plugging the connector in incorrectly and smashing all the pins flat.

    Another advantage to USB is that it's a vastly faster bus than PS/2. You won't find high DPI mice on PS/2 because there's just not enough bandwidth available. But then again you're relying on the polling mechanism to handle all of that extra data.
     
  14. Mega6

    Mega6 Gawd

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    because i still have ps2 accessories and told the mb manufacturers to keep the ports, ruining it for the entire world.
     
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  15. Sarra

    Sarra [H]Lite

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    I have an ancient programmable 10-key addon module. I used it as a game pad, or tried to, since it doesn't do key repeat. I did set it up for basic stuff in FS X before I got an actual gamepad. Then I got a HOTAS setup...

    Anyway. It's a 10-key addon module that has a PS2 passthrough. Since my last PC didn't have a PS2 port, I plugged it into a PS2 to USB adapter, and since I didn't have a PS2 keyboard, plugged a second adapter in and plugged my keyboard into it, and shockingly, that works. Only need the keyboard plugged in when you program it. If I was going to go back to FS X again, I'd certainly get it out and set it up again. It's super light, very durable, and has a million mile long cable (which would be super annoying for a laptop), it's easy to set up, and I can't see myself getting rid of it. It cost me $2 at a recycling store, plus $6 for two PS2/USB adapters.

    So, yeah, there's still PS2 stuff around. Might not be 'modern', and you aren't likely to buy an actual keyboard any time soon that uses it, but still, I'd like to have a port on my PC for it. Ah well.
     
  16. Mega6

    Mega6 Gawd

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    Still waiting on my PS/3 port upgrade.
     
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  17. Nenu

    Nenu Pick your own.....you deserve it.

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    I lost count of the number of times I've needed the PS/2 port in the last 5 years.
    One thing is for certain, it always works in any situation for mouse or keyboard, whichever is most convenient.

    It can be due to many things:
    Motherboards with only USB 3.0 ports that get no function until the driver is installed. ie when installing an OS or using safe mode.
    An OS foobar where the USB ports are screwed up and you cant fix it without a mouse or keyboard.
    Bios setting that gimps certain USB keyboards or disables the USB ports.
    Faulty motherboard.
    ...

    I always keep a few PS/2 keyboards and mice, just in case.
     
    Last edited: Apr 29, 2018
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  18. Skylinestar

    Skylinestar Limp Gawd

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    If it ain't broke, don't fix it.
    I do have some experience with slow/poor detection of USB in certain BIOS/UEFI. I did have an experience where all the USB ports went dead on a motherboard. For PS/2, it just works. 100% reliable all the time.
    I would prefer a motherboard to have PS/2 ports though as a safe guard.
    In fact, I just bought a brand new PS/2 keyboard last week for $7. Can't find any USB keyboard as good as this at this price range.
    https://hardforum.com/threads/microsoft-magic-keyboard.1959354/
     
    Last edited: Apr 30, 2018
  19. ZeqOBpf6

    ZeqOBpf6 Limp Gawd

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    Okay, I guess the question is why are keyboards even USB? At least as an option, give us ps2. It frees up a USB port, and seems like it has no downsides. It's not like laptop users desperately need a keyboard.
     
  20. ProfessorUtopia

    ProfessorUtopia [H]Lite

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    I'd wager you can't synchronize FragHarderâ„¢ Disco Lights over PS/2. ;)
     
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  21. ACC

    ACC n00bie

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    PS/2 is better than USB for entering BIOS and with lower latency , as it doesn't rely on polling.
     
  22. WhoBeDaPlaya

    WhoBeDaPlaya 2[H]4U

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    For installing older OSes without native USB3 drivers, since Intel and AMD decided to yank EHCI from newer chips.
     
  23. EchoWars

    EchoWars Limp Gawd

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    I have an Alps Glidepoint PS/2 keyboard with a built-in touchpad that I bought when I built my first system back in 1996. $100 at the time, which was insane for a keyboard, but it still works peachy 22 years later. Alps stopped supporting the touchpad drivers many years ago, so while the pad still will move the cursor and the touchpad buttons still function with the generic Win10 drivers, no tap function for the pad.

    What I always loved and would find hard to do without, is the spacebar is split...the left 1/3 of the spacebar territory is 'backspace'. Lovely for gaming (usually used for toggling 'crouch').

    Even found a pic:
    aF6I5JD.jpg
     
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  24. WhoBeDaPlaya

    WhoBeDaPlaya 2[H]4U

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    Still banging this babe daily (as well as more warm/gooey ones)

    Black-Model-M-Trackpoint.jpg
     
  25. Mega6

    Mega6 Gawd

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    bet it doesn't look that good.
     
  26. gwarren007

    gwarren007 [H]ardForum Junkie

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    Its there for legacy equipment running an older OS to function.
     
  27. GiGaBiTe

    GiGaBiTe Limp Gawd

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    Ha, I would love to hear a recording of you calling their tech support line asking them to honor their lifetime warranty. Not that you currently need it of course, but them regretting printing it on a box 22 years ago lol.
     
  28. Formula.350

    Formula.350 Gawd

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    *nudge* I see you like them darker toned ones, eh? ;):D
    But man... even you keyboard has a clit! :cool: (I'm assuming that is allowed to say, considering shit and fuck are acceptable... lol)



    I'm sorry, that's mainly the only reason I am posting :( Alas, I'll admit, that I also keep a PS2 KBM around as well, and was initially because, as mentioned, the older BIOSes either didn't support USB input or didn't initialize them quick enough to be able to even access the BIOS lol

    Though.... I do have a bit of a gripe that is somewhat still on topic...
    I'm a guy with relatively simple need when it comes to keyboard or mouse. I'm a gamer, but since I live in a rural area that ISPs don't give a shit about, online gaming is not something I do now that I don't have a capable internet connection (speed is, well sub-part, and ping time isn't horrible, it's just the limit cellular bandwidth). I currently have a Thermaltake Challenger Pro keyboard, was a review sample back when it came out. Overall I was impressed. It's a standard rubber diaphragm keyboard, but a "gaming" keyboard nonetheless, as it was before switch-keyboards started taking off.

    Therein lies my gripe... These days it seems you're a bit screwed as far as getting a keyboard. You either have to settle for something that's barely better than a Dell keyboard but is at least affordable... or pay out the goddamn ass to get one that has the features you want (see: tailored for gaming) but is expensive as hell because now EVERY keyboard is equipped with friggen switches!!

    Full disclosure, I've not used a switch keyboard, at least in modern times where I can make a comparison, so I really can't say how much better or different the usage is. What I CAN say is that I do NOT need to spend $20 more for a keyboard just because it now has switches. I hate that there is no quality middle-ground anymore. Seem like if you want a gaming keyboard from a reputable company that you want to buy a product from, you have to buy one with switches, there are no diaphragm variants.

    Last rant goes back to the keyboard I have being a review sample. I believe I revised my conclusion after a year to point out that the keys were wearing, and had already began to after only a few months. However, if I was able to have revised it again after 2 years, I'd have flat out said DO NOT BUY THIS KEYBOARD. :( It's been... man 7 years now, since that review, and want to know what letters you can still read 100%? Q, Y, U. That's it. Hell, even <, > ? and ; as well as the L-Shift and L-Ctrl are worn off!

    After a year, I had seen where it was going, and emailed Thermaltake's support, asking if I could buy a full replacement of keys, because the keyboard itself is fine (yes, is, I still use it despite this, as I thankfully I can look at the screen to type). I never even heard back from them :shifty: I was going to even buy the lesser model to recap mine, but after researching, it looked like the slot they ride in is rotated 90deg :meh: *sigh* I see the "Prime" version is cheaper now at least, but of course it lacks a USB hub like the Pro :\ Given the fact I'm a "couch gamer", my keyboard's long ass cable and hub is kinda needed, since my mouse relies on it (no, I won't use Wireless lol). Oh well. Given in my new place my computer will be in a different spot in relation to couch and TV (about 2 feet further back), might just be time for a small powered USB hub. At least then I'd be able to use the USB ports for useful things considering what's on the keyboard can't even access thumb drives w/o Windows screaming "underpowered!" heh
     
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  29. ir0nw0lf

    ir0nw0lf [H]ardness Supreme

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    We have a PS/2 port barcode scanner on our POS machine at work. Lots of PS/2 port stuff like that around.
     
  30. jmilcher

    jmilcher 2[H]4U

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    Some people still swear by these. I mean, you have to go back with your IBM mechanical keyboard from the 90's. Right hipsters?

    Jokes aside I haven't used this port in 15 years I'm sure.
     
  31. PhaseNoise

    PhaseNoise Gawd

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    It's a port that works and some people have things that could connect to it. That's the real reason.
     
  32. jmilcher

    jmilcher 2[H]4U

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    Then where did the parallel port, and serial port go? And what do most enthusiast boards not have vga?
     
  33. PhaseNoise

    PhaseNoise Gawd

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    Those ports serve obsolete devices, which is different than the PS/2 keyboard port. Old keyboards are not obsolete, we've just deprecated the connector in favor of a multipurpose bus. If space or cost is an issue, PS2 is dropped. If there's space and a few sheckles to add it, many companies still do to make a sale to the graybeards who will die before giving up their IBM keyboard.
     
  34. jmilcher

    jmilcher 2[H]4U

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    Arguably ps2 keyboards are obsolete devices. Sure perhaps just the port type is obsolete, they still may be functional devices. But so are IDE hard drives.
     
  35. PhaseNoise

    PhaseNoise Gawd

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    I'll reiterate the point I made: "It's a port that works and some people have things that could connect to it".

    Nobody is buying a new motherboard with the excited hope of connecting that good ol' 120 MB Maxtor. Some percentage of people ARE looking to buy one with the intent of connecting a PS/2 keyboard. That's why there are PS/2 ports on some boards but never any IDE ports. It's that simple.

    If Gigabyte or anyone else thought the addition of an IDE port would result in profit positive sales, we'd have IDE ports.
     
  36. mvmiller12

    mvmiller12 Limp Gawd

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    They did get rid of PS/2 ports for a while. The resulting backlash apparently changed some minds. Thank God for that.

    Also, most motherboards still have a serial port header, it's just that the bracket for it is not included with the board. These are still used for the Intel Management Engine (and AMD equivalent).
     
  37. jmilcher

    jmilcher 2[H]4U

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    There have been ps2 adapters since ps2 ports began to be phased out in favor of USB etc.

    It all boils down to opinion. I was surprised to see the port on my z170 board in 2015. I was recently surprised to see it on my x470 board. So apparently some people like it.

    Curiously it only seems to be on higher end boards. At least the ones I've looked at.
     
  38. Krenum

    Krenum [H]ardForum Junkie

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    For redundancy. I still have a PS2 Keyboard that I use from time to time in case my USB ports aren't responding properly before driver updates.
     
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  39. pentiumiiislota

    pentiumiiislota n00bie

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    I could have used a ps2 port when trying to install windows on an am4 motherboard since usb stopped working. Instead I had to make a usb stick with the drivers and windows on it.
     
  40. Formula.350

    Formula.350 Gawd

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    I was actually going to make this same point... except, when I looked at my MSI X370 Titanium, I was unable to locate a COM header... heh So I think even those are now probably included only sparingly, and in my mind I'd figure it'd be lower cost motherboards where the buyer is a person looking for an inexpensive system that is still capable of handling some legacy tasks.

    Then again, there's always USB-Serial connectors (which I don't know how "reliable" they are these days, I know early on they were flaky).
    There's also these, too...
    AE7R_1_20170710454965746.jpg

    But, I suspect most Super I/O chips on motherboards have native Serial support, and is probably the decision of the motherboard maker on whether or not to include a header.