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geekhack Community => Keyboards => Topic started by: TheMightyGoat on Fri, 27 May 2011, 11:03:49

Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: TheMightyGoat on Fri, 27 May 2011, 11:03:49: I'm just old enough to remember when all keyboards were PS/2 and just when USB keyboards started to become popular, I didn't quite see the appeal. They take up valuable real estate in a USB port that could be used for a different device. They don't always register in BIOS. What's the point? I assumed there must be some hidden performance perk somewhere.

As I started researching keyboards more (only recently), it seems all the benefits go to the PS/2 connection, including full key rollover; something that is of huge debate with USB keyboards and could be completely eliminated.

Why are USB connections used at all, then? My only guess is that they're cheaper to manufacture or perhaps easier to power the board off the USB connection.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: DaemonRaccoon on Fri, 27 May 2011, 11:13:18: Welcome to Geekhack!

I'm sure Ripster will be by shortly to explain why USB is mo' better.

EDIT: Ninja'd
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: db26 on Fri, 27 May 2011, 11:18:52: The shift to USB specifically, from PS/2 was for uniformity of ports, I'm sure. Not only does that make it easier for consumers, but its easier to manufacture, and uses up less space on a motherboard.

The shift from PS/2 in general was necessitated by a few shortcomings. Mainly, that it is not hot-pluggable. Although most hardware can support hot-plugging PS/2, it is not supported by the spec and can potentially damage equipment. Additionally, the connector itself is not ideal. The round shape makes it hard to plug in with the correct orientation without careful inspection/practice, and attempting to plug it incorrectly can lead to the pins bending or eventually breaking.

The switch to USB may not have been ideal, but the switch from PS/2 was inevitable. USB just happened to be the convenient option at the time, and still remains.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: TheMightyGoat on Fri, 27 May 2011, 11:57:40: I'd rather deal with a connection not being hot-swappable than not being supported in BIOS. Granted, I tend to plug my keyboard into my computer and leave it there, while there are people who would need to swap peripherals for testing and other reasons.

While we're on the subject, maybe someone can answer a question for me that I haven't quite found for myself through searching: Is support of a USB keyboard in BIOS dependent upon the BIOS or the keyboard itself?
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: alaricljs on Fri, 27 May 2011, 12:04:13: Quote from: TheMightyGoat;352064
Is support of a USB keyboard in BIOS dependent upon the BIOS or the keyboard itself?

Yes.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: TheMightyGoat on Fri, 27 May 2011, 12:13:05: That is as I had surmised.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: Pylon on Fri, 27 May 2011, 13:41:27: USB killed a ton of ports. It largely killed serial and parallel, and also took the 15-pin game port among other things.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: Surly73 on Fri, 27 May 2011, 13:52:06: I'm happy for the transition to USB in almost all cases. USB can be chained, hubbed, whatever, and all ports are the same (including backwards compatibility between USB 3, 2 and 1 for the most part). This is kind of like everyone deciding that we should embrace ethernet as the standard LAN technology, instead of persisting with the use of Appletalk, Token Ring, and other technologies. The others may have had some advantages, like BETA being higher quality than VHS, or token ring handling extreme loads more gracefully than ethernet, but settling on one standard usually moves things forward and opens up new capabilities down the road. It's not universally better, but it's still moving ahead. The universal adoption of USB has led to all kinds of things that plug into USB, even just for power to charge. No more serial ports, parallel ports, running out of said ports, baud/parity errors, expensive and customized cabling for peripherals etc...

I like that I can connect my keyboard and mouse to a hub, instead of stringing them individually to the back of my PC. I like that standards were defined (notice I didn't say adopted) concerning power consumption and allocation. I don't miss the game port at all.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: Findecanor on Fri, 27 May 2011, 14:04:59: I think also that at the beginning, the keyboard was intended to contain a passthrough (actually, a small hub) for the mouse so that you needed only to use one port on the computer.
Apple was one of the first to use USB for mouse and keyboard, and they have included a hub in all their wired keyboards since. Microsoft did too back in the early 00's.

Unfortunately, most cheap USB keyboards for the PC don't have USB hubs in them. To keep costs down, I'm sure.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: firestorm on Fri, 27 May 2011, 14:45:02: From an IT standpoint, USB has had its up's and downs for us. Gone are the days of an unusable system because of a dead PS2 port. However, those days were very rare. Instead, we get occasional glitches where a mouse or keyboard (usually mouse) drops out. It probably happens once every 2-3 months among 80-90 users. Fortunately, just unplugging the device and plugging it into another port always fixes it, if not just unplugging and replugging into the same port.

I was never overly concerned about hot-swapping PS2, but its nice that it is officially supposed on USB; great for swapping out bad keyboards and mice.

I also love being to plug them in anywhere. It's convenient for troubleshooting or when we have PC's on "the bench". Great for headless (no KB/Mouse/Monitor) systems.

USB has been MUCH better for servers. We finally got some Avocent KVM switches, but some of our servers wouldn't detect a keyboard or mouse on restart. The KVM's weren't maintaining an active connection for some systems for some reason. That's a non-issue with USB.

I haven't run into a problem with a USB keyboard during POST since the PS2 days. Some of our servers are old enough that USB could be a problem during POST, so we stuck to PS2 for those. Otherwise, aside from possibly the 6KRO limitation, I really have no complaints.

We did have one incident where USB or something got disabled in XP, but someone had restarted the computer using the mouse. I don't remember what happened, except that we couldn't use a keyboard and thus could not log in locally. It involved a new IT tech. No PS2 ports on this machine, otherwise that would have been the workaround. I ended up connecting via Remote Desktop to fix it.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: xwhatsit on Fri, 27 May 2011, 19:29:58: The main issues the OP seems to have is BIOS issues with a USB board. Never having had these (and dealing with all sorts of weird and wonderful single-board and other industrial PCs in my line of work), I haven't got a problem with USB. In fact yesterday, I was happily navigating the BIOS on an ancient 400MHz Celeron without a hitch. For the rare occasions one has to actually use the BIOS, and you happen to have a buggy BIOS that doesn't like USB keyboards, you can always pull a PS/2 board out of the cupboard.

In an industrial setting it's perfect. Touchscreen for everyday operation, plug in a keyboard (while it's running!) if something breaks and you need to. Only need one USB port for the operator, so that's only one (you need USB anyway for flash drives) expensive dustproof/waterproof port on the outside (PC is hidden in the depths of the machine). Well-defined and understood maximum cable lengths. Put in a hub if you need more length. PS/2 would add a lot of cost and headaches.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: DesktopJinx on Fri, 27 May 2011, 20:56:14: Killing the USB hubs, what a great idea for local denial-of-service. I need to look into this further :)
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: quadibloc on Fri, 27 May 2011, 21:47:15: Aside from the USB interface being newer, so that a computer can bill itself as "legacy free", it does allow quite a bit more power to be supplied to the keyboard, which allows for extra features. A USB keyboard can switch over to a mode that uses a custom driver - that not only would allow it to have full N-key rollover, but in addition could allow for new functionality - for example, think of the Optimus Maximus keyboard.

Still, just plain keyboards might as well have a standard just plain keyboard port. That way, the same keyboard can be used on older or newer computers. On the other hand, the same USB interface - although some different keycodes - applies to the Macintosh and to Sun computers as with the PC. The pre-USB interfaces for all three for keyboards were different. And so an HHKB can be used with all three of them.

Quote from: xwhatsit;352235
For the rare occasions one has to actually use the BIOS, and you happen to have a buggy BIOS that doesn't like USB keyboards, you can always pull a PS/2 board out of the cupboard.
Who needs a buggy BIOS? All one needs is an older computer, designed before USB keyboards were invented.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: Mr. Perfect on Fri, 27 May 2011, 21:52:30: Wow, another PS/2 fan? Just build yourself one of Soarer's PS/2 to USB converters (http://geekhack.org/showwiki.php?title=Island:17458), it does full NKRO and works with Windows, Mac and Linux.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: xwhatsit on Sat, 28 May 2011, 00:14:38: Quote from: quadibloc;352275
Who needs a buggy BIOS? All one needs is an older computer, designed before USB keyboards were invented.

That would make sense, except for the fact you'd *already* be using a PS/2 keyboard with a computer designed before USB keyboards were invented.

If you don't have a choice, you don't have a choice.

It's like saying `6x6 medium format film is way better than 35mm, because you can't use 35mm in a Hasselblad'. Rather facetious.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: Hydroid on Sat, 28 May 2011, 01:16:32: Quote from: ripster;352323
UEFI for 3TB Hard Drives is needed anyway.

Once you get rid of the BIOS then bye bye PS/2 chip.
Show Image
(http://upload.wikimedia.org/wikipedia/commons/0/09/IT8705F.jpg)

Herro UEFI!
Show Image
(http://www.dvhardware.net/news/uefi_april07.jpg)

Haha, from what I've read on this forum thus far I'm not surprised to see you posting that anyway. I was just reading this thread through and was going to post about the UEFI, but you beat me to it. :P The last system I build had a UEFI instead of BIOS, I really liked the snappy bootups. It actually had a timer setting so you could slow it down enough for you to read the output otherwise it just snapped right to windows before you could do anything.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: The Solutor on Sat, 28 May 2011, 04:26:27: Quote from: ripster;352278
Not so sure about the power thing. 275ma PS/2 spec.

Most of the PS2 ports can provide even 1A or more w/o any problem.

Do you forgot the helper cable to external HDD working via PS2 power because the USB one was insufficient ?

Quote
UEFI for 3TB Hard Drives is needed anyway.

No it's not true.

UEFI is needed to boot an OS from the 3TB driver (which is a bit pointless), not to use the drive.

To get the driver working as a storage solution a GUID ready os is sufficient, usually the x64 versions, but also linux 32 or XP32 with a GUID driver works.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: elef on Sat, 28 May 2011, 04:54:05: Quote from: The Solutor;352362
UEFI is needed to boot an OS from the 3TB driver (which is a bit pointless), not to use the drive.

You yourself know that's BS, you just posted this crap to disagree with Ripster. If I'm going to have a 3TB drive, that's all the space I'm going to need. I don't want to add another drive just to be able to boot. Not to mention the fact that when these drive sizes hit laptops, the option to add another drive won't even be there.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: The Solutor on Sat, 28 May 2011, 05:57:24: Quote
If I'm going to have a 3TB drive, that's all the space I'm going to need.

Normal people in these days use an SSD for the OS and a large HDD for data, better a couple of large disk (in raid1), because one don't want to lose 3TB of data in one step because a disk failure.

Quote
Not to mention the fact that when these drive sizes hit laptops, the option to add another drive won't even be there.

When this will happen, UEFI will be mature enough to be a good choice.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: elef on Sat, 28 May 2011, 09:59:04: You're funny, Solutor, with your proclamations about "normal people" and what is and isn't needed or right in the world of tech. You seem to know a fair bit about tech, and a whole lot less about the world. In case you didn't get the memo: most computer buyers don't know about SSDs, or about installing several HDDs in a machine. Normal people just get a computer that looks convincing and use it as is. They don't want to reinstall their OS or clone a drive etc. Also, hardly anyone cares about desktops anymore, apart from gamers on a budget and some power users with insane performance needs.
Full disclosure: I have a 120 gig Agility 2 in my laptop, so I'm not exactly new to the idea of fast SSDs. I just know they are a niche product for now. Fast SSD + big HDD is indeed best setup for most people who use a desktop, but hardly anyone uses a desktop and most people don't need or want the best possible setup. So yeah, being able to boot from your HDD is fairly important.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: The Solutor on Sat, 28 May 2011, 10:15:16: Quote
You're funny, Solutor, with your proclamations about "normal people" and what is and isn't needed or right in the world of tech.

If I speak about good cuisine, I don't care about how much people are used to to go with Macdonald's.

Whatever Steeve Jobs thinks a PC is not a blender or a microwave oven, and if one wants to use it in a conscious way a bit of knowledge is needed.

I'm referring to this kind of user and the world is plenty of them.

The average dumb user couldn't care less if his data are getting lost or if his pc has BIOS or UEFI, so speaking about this kind of user is just time wasted.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: ch_123 on Sat, 28 May 2011, 10:38:13: Quote from: The Solutor;352362
Most of the PS2 ports can provide even 1A or more w/o any problem.

I'd be pretty worried about typing on a keyboard that uses 4 times the specified limit for the PS/2 interface.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: The Solutor on Sat, 28 May 2011, 10:42:14: Quote from: ch_123;352438
I'd be pretty worried about typing on a keyboard that uses 4 times the specified limit for the PS/2 interface.

You are used to type on keyboard that drains more than 10 times the current drained by an average keyboard so, why don't go further ?

Let say, a model F backlit with incandescence microlamps ?
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: The Solutor on Sat, 28 May 2011, 10:55:23: Quote
I kinda doubt many PS/2 ports allow 1 amp

On modern mainboards, PS/2 power is almost always the same that powers USB, so the limit is not 250mA nor 1A, is 500mA like USB2.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: Dezeer on Sat, 28 May 2011, 11:14:19: It could be long before Intel or AMD forces to drop PS/2 port. From 232, socket 1155 motherboards, there is 110 that has mouse/keyboard PS/2 port and 80 that has keyboard PS/2 port. 88% of 1156 has got PS/2 for keyboard, 95% of AM3 has PS/2 for keyboard even the AM3+ will have like +75%.

IDE/PATA connector is finally being left out, VGA is to be killed in 2015, but when will PS/2 die?
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: noodles256 on Sat, 28 May 2011, 11:21:52: from his xarmor
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: redpill on Sat, 28 May 2011, 11:29:44: Every computer needs a keyboard, I think it makes sense to have a dedicated port for it. They should just update the PS/2 format so that it can be hot plugged while preserving NKRO and a dedicated channel that gets priority over USB devices.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: Dezeer on Sat, 28 May 2011, 11:41:40: Quote from: ripster;352448
Where are you finding those numbers?

I took them from http://geizhals.at/?o=9 there likely is a lot more mainboards than those.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: HaveANiceDay on Sat, 28 May 2011, 12:13:53: Quote from: redpill;352459
Every computer needs a keyboard, I think it makes sense to have a dedicated port for it. They should just update the PS/2 format so that it can be hot plugged while preserving NKRO and a dedicated channel that gets priority over USB devices.

ಠ_ಠ
Every computer needs a mouse(shut up old man, it does!), so let's just update the mouse ps/2.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: redpill on Sat, 28 May 2011, 13:13:12: Quote from: HaveANiceDay;352476
ಠ_ಠ
Every computer needs a mouse(shut up old man, it does!), so let's just update the mouse ps/2.

I don't think it's the same logic. For one, you typically don't have mice with more than 6 buttons anyway, so NRKO is not even a possible issue. For two, there isn't the same concern for a BIOS non-recognition issue with a mouse.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: DesktopJinx on Sat, 28 May 2011, 13:15:05: redpill: I like PS/2, but if any-one-of-these-ports works, why dedicate a port? Every living room has a TV, why not have a dedicated power connector in the wall for it?

The thing I dislike about USB is that it doesn't take a lot of force to pull a cable loose. (HDMI isn't much better.) OTOH, it's easier to plug in by feel alone -- PS/2 keyboard connectors were often made in such a way that you could tell where the "top" of the connector was, but anyone who's had to reach behind a desktop computer to plug one in blind knows it's still a fussy operation, and that's before you consider that computer manufacturers sometimes put the ports in "upside-down" on some models.

I still prefer PS/2, but it's because I'm old and nostalgic and my favorite keyboards use it. I know that it's the past. I stopped hearing stories from techs about USB keyboards that would only work in a particular USB port on a machine a couple of years ago (finally retired all the HP Compaq D510 and D530 USDT)... of course that was because they switched back to PS/2, but they've since switched to USB again; seems HP finally figured it out.

And I'm starting to pay for my nostalgia, since PS/2 keyboard ports on new hardware don't really work right anymore, no doubt a side effect of the dwindling numbers of old PS/2 keyboards and the general disinterest in them.

What's the last Apple computer that had a PS/2 port? Where did FireWire go? Why don't printers use parallel ports? Why aren't external hard drives still using SCSI? Where's my game port? What am I going to do with this box of DB9-DB25 serial adapters?

Standards are good, and USB is a mature standard that's suitable for keyboards. PS/2 is hanging around because some big corporate/government purchasers are slow to accept change, and there are still some pockets of infrastructure (old switchboxes, for example) that call for it. But I'd expect the next generation of motherboards from each manufacturer to be PS/2 free, except maybe for one corporate model and one gamer-elite model, and the latter just to cater to the prejudiced.

Any technical benefit PS/2 might have enjoyed is mere trivia in the face of USB's advantages. USB is easier to plug in, it's ubiquitous, and it's hot-pluggable. USB's problems are in the past; PS/2's biggest problems are in its future.

As for why the PS/2 is not still the standard, the above-linked Peeter Seebach article hosted by IBM developerWorks nails it: Apple's USB-only iMac forced the industry to adopt USB. And we're much better off for it.

In fact, with USB 3.0, we could and probably should lose all those audio ports, and even HDMI could get the "legacy" tag. Ethernet too except that it still offers greater distance. Okay, HDMI is well-entrenched, and I can already hear the arguments about how USB isn't stout enough or specialized enough or supported enough, but give it time...
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: Lanx on Sat, 28 May 2011, 17:47:00: To recap for those who have had computers "after" usb (and don't even remember when bill gates demo'd usb and it blue screened"
we had two ps/2 ports or 1 ps/2 port and 1 5din keyboard port
1 15pin midi/game port
1 serial port /modem- sometimes mouse
1 parallel port usually for printer
1 50 pin scsi port/ usually for scanner (unless it was a 68pin, wow ultra wide)

it was really a hot mess w/o usb but it was the best way to scam customers on cables. every store sold a parallel cable for 20bucks, in truth cost on these things were $1 and no printer ever came with a parallel cable, which was also annoying because the parallel port was one of the fastest ports at the time. I remember having a diamond rio, basically the first mp3 player, i think it was 32megs built in and connected via parallel port with another bulky adapter on the end for the printer to connect to.

In short usb is great! and usb3 really should be adapted better over crappy thunderbolt. Just like how now in the industry pretty much every cell phone is charged via micro usb, it's great, don't have buy funky car adapters any more or funky wall chargers, just have a few 1ft or 3ft usb to micro usb cables around and you can just have $1 usb car chargers and 1$ usb outlet chargers, of course apple messes this up with their horrible connector that breaks.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: HaveANiceDay on Sat, 28 May 2011, 18:53:08: Quote from: redpill;352495
I don't think it's the same logic. For one, you typically don't have mice with more than 6 buttons anyway, so NRKO is not even a possible issue. For two, there isn't the same concern for a BIOS non-recognition issue with a mouse.

Ha! I heard some doods like their 17 buttons on the mouse (http://www.amazon.com/Razer-Laser-Gaming-Mouse-RZ01-00280100-R3/dp/B002MPPRPO).
Also, BIOS is no longer a concern because UEFI is already here to stay. And guess what, you can use mice in it. The madness.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: IvanIvanovich on Sun, 29 May 2011, 15:48:20: psht, ps/2. too new fangled for me. bring back the xt standard! also clearly punch cards were far superior to disks for storing data.
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: ricercar on Sun, 29 May 2011, 21:19:01: Quote from: ripster;352477
Cloud computing is the future.

Who gives a hadoop about cloud computing?
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: kps on Mon, 30 May 2011, 10:52:52: Quote from: TheMightyGoat;352045
I'm just old enough to remember when all keyboards were PS/2

I'm just old enough to remember when no keyboards were PS/2.

... and there never was a time when all keyboards were PS/2 (http://en.wiktionary.org/wiki/parochial).
Title: Why are USB connections used for keyboards at all? Why is PS/2 not still standard?
Post by: woody on Mon, 30 May 2011, 12:34:03: I'm just old enough to remember ... remember .... umm, can't remember exactly what.