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IPAC USB or PS2
Tiger-Heli:
--- Quote from: RandyT on May 30, 2003, 06:10:41 pm ---
--- Quote from: rampy on May 30, 2003, 04:56:30 pm ---Just to make a silly point:
You most likely can hot swap in/out/off ps/2 keyboards while the machine is on (without hardware damage)... but windoze usually gets pissed and will make you reboot anyways =P
at least that's been my experience.
--- End quote ---
Hey Rampy!
How do I disagree with you without ticking you off :) ?
Seriously though, I haven't found this to be the case. Mouse? Yes, but not the keyboard. I routinely hot swap keyboards and encoders half a dozen times at a sitting, and I don't have to reboot.
The only thing that might get weird is the LED lock indicators. They could possibly get out of sync.
But it could also just be your/my keyboard :)
RandyT
--- End quote ---
How do I agree with RandyT without ticking anyone else off :-)
I too have swapped KB's many times and not had windows complain (Ooops . . . inserting foot ) Now that I think about it. These were AT keyboards (Large 5-pin DIN port). Anyways, I've never known windoze to care. I think I have seen the LED's get out of synch, tho'
FWIW!
u_rebelscum:
--- Quote from: TheManuel on May 31, 2003, 08:08:48 am ---
--- Quote from: planetjay on May 31, 2003, 02:42:11 am ---FYI. I have been a computer tech since before the PS/2 connector. ;) In all my years only one fuse has ever blown. And that one was from a keyboard that someone else had bent a pin on, and that pin went across 5v and GND. And I "fixed" that MB.
--- End quote ---
That's good news.
Does your comment apply to PS/2 in general including mice?
--- End quote ---
I'm not a computer tech, but I've removed & replugged both keyboards on mice in PS/2 ports. I've have no problems with keyboards (used to fix a "stuck" keyboard by unplugging & replugging in an old computer I had).
Mice, on the other hand, are more picky. Unplugging and replugging the same mouse: no problems. Unplugging and plugging in a different mouse rarely worked for me; but if I replugged the mouse I unplugged in the first place, usually things would go back to normal. (Makes sense with all the different mouse drivers.)
Just my experiences. *shrug*
AndyWarne:
I have always hot-swapped PS/2 before but was surprised to find that on three new socket 7 motherboards with VIA chipsets doing this locks up the keyboard controller on the M/B every time and the keyboard and mouse stop working until you power off/on.
Actually the motherboard manufacturers have been trying to dump PS/2 for ages as it is an interface without any proper standard and is generally a pain. We are starting now to see micro-ATX boards with no PS/2 but I expect it will be around for a few more years yet on full size boards.
On the subject of USB vs PS/2: In Windows 98 Microsoft didnt implement USB properly so it may be slightly slower than PS/2 although it's probably not noticeable. The problem mentioned above in DOS is a different issue, the I-PAC should not be used in DOS in USB mode as this is relying on the PC BIOS for support, which is not up to the job when it comes to high speed gameplay.
USB should be super-fast in XP and W2K which have a proper implementation. This should be especially noticeable in games which need simultaneous button presses, as all buttons are sent in one "report" at the speed of the USB bus instead of being piped down the PS/2 interface in a relatively slow manner.
RandyT:
--- Quote from: AndyWarne on June 01, 2003, 05:31:24 am ---
Actually the motherboard manufacturers have been trying to dump PS/2 for ages as it is an interface without any proper standard and is generally a pain.
--- End quote ---
Please explain this comment. I know the PS/2 interface pretty well and there certainly is a proper standard. IBM developed it and it is well documented. There is one thing you can always count on with a properly designed PS/2 device. You plug it in and it works.
--- Quote ---We are starting now to see micro-ATX boards with no PS/2 but I expect it will be around for a few more years yet on full size boards.
--- End quote ---
PS/2 Keyboards and mice probably outnumber their USB counterparts by at least 1000 to one. MB manufacturers know that forcing the consumer to purchase a new keyboard and mouse in order to upgrade their system will result in a significant reduction of their potential market.
It has also been my observation that these "USB only" systems don't seem to sell very well. Many fall into the set-top box / internet appliance category and I routinely see them in large quantities in the surplus listings. On the other hand, the hottest selling boards of this type are the mini-ITX Via boards (even smaller than the mini-ATX) and they have the full complement of PS/2 ports. So it appears that size doesn't matter.
This, coupled with the fact that it costs them very little to implement the interface (the code could be implemented on the same chip as the one that controls the USB, if it isn't already) tells me that the PS/2 ports will be with us until the consumer deems it unnecessary. And considering that there are other PS/2 devices used in commercial settings such as bar-code readers, card swipes, etc., that may be a very long time.
--- Quote ---....snip
This should be especially noticeable in games which need simultaneous button presses, as all buttons are sent in one "report" at the speed of the USB bus instead of being piped down the PS/2 interface in a relatively slow manner.
--- End quote ---
The USB keyboard is considered a "low-speed" device, as is the microcontroller used in devices that behave like one. The reports don't travel at the speed of the USB bus, but at the speed maintainable by the controller. Not that this speed is inadequate, but the statement you made here isn't true because the USB bus can handle speeds far in excess of these devices.
Also, USB is still serial by nature (Universal Serial Bus). The bits are piped down the line, one after another, just like the PS/2 or standard serial ports. Just because the bits are assembled into a "report" before sending doesn't mean it will have a positive effect on speed. In fact, it could take longer due to the extra processing required to do the report assembly, especially if two reports are used to circumvent the 6 simultaneous keypress limitation. But this will depend on a number of other factors as well.
But nonetheless, this "report assembly" is a step that the PS/2 interface doesn't need to perform.
Of course, for the most part, original arcade machines only dealt with the controls once every 1/60th of a second anyway, so all of this is probably moot ;).
RandyT
shmokes:
Randy, your post was too long to quote, but I disagree with a few things you say. For one, the writing is on the wall for the PS2 port. Sure it will be a few years, but more and more the keyboards and mice in the stores are USB (sometimes they come with a USB to PS2 converter). The consumers have already said that they don't want PS2 anymore. Or rather, getting rid of PS2 simplifies the attachment of devices to the PC, thus the *average* consumer benefits and is less scared of the beast. PS2 is going the way of the floppy drive (Both Dell and Gateway sell their PCs without floppy drives by default now).
Also, regarding your comment about the USB port suffering because of its serial architecture.....I don't know too much about this but perhaps you could explain why this is a limitation. We are just now moving from a parallel IDE bus to a serial one and with the first iteration we jump from a maximum of 133 MB/sec with parallel to 150 MB/sec with the new Serial ATA. They also have a lot of room to push that bandwidth up steadily throughout the next few years.