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#1
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PS/2 KVM switch
Hi. This is my first post on this board.
I have a two computers (both Pentium IV's running Windows XP) and an IOGear KVM switch. The KVM switch has PS/2 ports for keyboard and mouse, and I'm finding that most new computers don't have PS/2 ports. I'm hoping to find a reliable way to add PS/2 ports to a computer that doesn't have them. I phoned up IOGear Tech Support and asked if I could just use a USB to PS/2 adapter cable like this one: http://www.amazon.com/Syba-Adapter-C...sb+ps2+adapter and was told that it wouldn't work. I've been able to find PCI cards that allow me to add two PS/2 ports for keyboard and mouse, but PCI slots on motherboards are also becoming rare. Nowadays, lots of motherboards only come with PCIe slots, and my understanding is that you can't use a PCI card in a PCIe slot. I've not been able to find a PCIe PS/2 port card. What I have found is a "card" (so to speak) that doesn't use a slot: http://www.sybausa.com/productInfo.php?iid=799 But I can't say that this "card" would work any differently than the adapter cable linked to earlier. After all, it still connects two PS/2 ports to a USB port just like the adapter cable. People have suggested a software solution like "Synergy". Apparantly, you load the Synergy program onto both computers, and the computer monitor shows what's going on on both computers depending on where you move your mouse. So, it acts kinda like a KVM switch. I use one computer to run my business and one computer for surfing the net. I like the idea of having the computers physically separated because if I get a virus on my internet computer, I simply format the hard drive and reload Windows XP. I'm concerned that with only this Synergy software, if I get a virus surfing the web, both computers will get infected. With a KVM switch, there's no way a virus can get from my internet computer to my business computer. Can anyone think of a sure fire way to add PS/2 ports to a computer that doesn't have them so that I can continue using my KVM switch. If push comes to shove, I might just have to buy a new 4 port DVI or HTMI USB KVM switch. |
#2
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PS/2 KVM switch
On Sun, 2 Feb 2014 15:06:40 -0800 (PST), NestorK
wrote: I'm hoping to find a reliable way to add PS/2 ports to a computer that doesn't have them. - The practical way to make that approach is through USB. From USB your options are the widest possible. I suppose I'd have used converters for PS2-to-USB at some point, although better in this case, in my opinion, to go with the flow and stick within current standards, as USB is presently king of the hill over the I/O realm of devices. The PCI thing you mention is partially true, insofar that fewer slots are available. Of course they're not going to cut their own throats with PCI-E and game-boys willing and ready to shell out on $200+ graphic cards. Practically the only thing left with mass appeal to ostensibly computers with power and the balls to do it: to render them into an idiocy of segmented appeal games hold;- the rest are migrating to gadget tablets that for nicely fitting into a purse always on the run to conditionally shop. Same goes for PCI, no throats bleating just to be cut today, not with another valid computer marketing segment, such as hi-end PCI soundcards from musical reproduction to recording purposes, among others, what few odds and sundry ends are adaptable to PCI. Without doubt, the greater MB purchases by far go to people with simply an aim to bring up the computer on the internet, without much interest in expanding on them;- and the sales are a horror of that reflection, as droves have migrated to such as chromebooks and whatever [all] else similarly offered: New and Improved, Better, and, only if you act now, Idiot Proof: Your Dream Come True. And that's totally ignoring the business segment purchasing computers. |
#3
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PS/2 KVM switch
NestorK wrote:
Hi. This is my first post on this board. I have a two computers (both Pentium IV's running Windows XP) and an IOGear KVM switch. The KVM switch has PS/2 ports for keyboard and mouse, and I'm finding that most new computers don't have PS/2 ports. I'm hoping to find a reliable way to add PS/2 ports to a computer that doesn't have them. I phoned up IOGear Tech Support and asked if I could just use a USB to PS/2 adapter cable like this one: http://www.amazon.com/Syba-Adapter-C...sb+ps2+adapter and was told that it wouldn't work. I've been able to find PCI cards that allow me to add two PS/2 ports for keyboard and mouse, but PCI slots on motherboards are also becoming rare. Nowadays, lots of motherboards only come with PCIe slots, and my understanding is that you can't use a PCI card in a PCIe slot. I've not been able to find a PCIe PS/2 port card. What I have found is a "card" (so to speak) that doesn't use a slot: http://www.sybausa.com/productInfo.php?iid=799 But I can't say that this "card" would work any differently than the adapter cable linked to earlier. After all, it still connects two PS/2 ports to a USB port just like the adapter cable. People have suggested a software solution like "Synergy". Apparantly, you load the Synergy program onto both computers, and the computer monitor shows what's going on on both computers depending on where you move your mouse. So, it acts kinda like a KVM switch. I use one computer to run my business and one computer for surfing the net. I like the idea of having the computers physically separated because if I get a virus on my internet computer, I simply format the hard drive and reload Windows XP. I'm concerned that with only this Synergy software, if I get a virus surfing the web, both computers will get infected. With a KVM switch, there's no way a virus can get from my internet computer to my business computer. Can anyone think of a sure fire way to add PS/2 ports to a computer that doesn't have them so that I can continue using my KVM switch. If push comes to shove, I might just have to buy a new 4 port DVI or HTMI USB KVM switch. As far as I know, there is only one PS/2 chip still in production. Your Syba product (second link), the picture is intended to show the Chesen USB to PS/2 converter chip. As far as I know, the Chesen chip is out of production. Some other (ITE?) chip is being used now. So Syba might be silently changing over to the other chip. When you purchase a PCI to PS/2 card, it still uses the Chesen. The board consists of a PCI to USB chip, plus the Chesen USB to PS/2 chip. If someone made a PCI Express version, it would consist of a PCI Express to USB, plus a Chesen chip. The adapter cable, the one with USB on one end, and dual PS/2 on the other end, the Chesen chip is hidden in a plastic blob in the middle of the cable. The Chesen chip contains an 8 bit microprocessor and ROM firmware. That means the protocol conversion is firmware mediated. The 8 bit microprocessor is likely similar to an 8085 running at 12MHz or 24MHz or so. So they're all basically relying on the same concept, and just packing a little extra infrastructure around it as the situation requires. The conversion is done with USB, and any other card format, just goes from bus standard to USB, before the Chesen is added to the picture. Keyboard protocols are pretty mysterious stuff. Any mistakes Chesen made in writing their firmware, those changes would be hard-fought, and they wouldn't exactly be telling the world what they had to do to fix them. You can't flash upgrade that chip, and if it has bad firmware, you have to buy another adapter. Since the Chesen chip no longer ships, the replacement chip could have its own firmware issues with converting certain key sequences. The fact there is a processor in there, should suggest to you they weren't really sure what they needed to do, and it was made programmable so they could deal with "surprises". That's my guess. And some KVMs, do have weird key sequences for inline switching. Paul |
#4
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PS/2 KVM switch
On Sun, 2 Feb 2014 15:06:40 -0800 (PST), NestorK wrote:
I phoned up IOGear Tech Support and asked if I could just use a USB to PS/2 adapter cable like this one: http://www.amazon.com/Syba-Adapter-C...sb+ps2+adapter and was told that it wouldn't work. I have been using one of these, http://www.amazon.com/Keyboard-Adapt...NI/ref=sr_1_81, for years with an IOGear KVM switch ... successfully. YMMV. |
#5
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PS/2 KVM switch
Greg:
So, you just plug the adapter cable into ANY? USB port on your computer and plug the KVM cable for that computer into the PS/2 ports on the other end of that adapter cable and it works? |
#6
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PS/2 KVM switch
On Mon, 3 Feb 2014 09:24:52 -0800 (PST), NestorK wrote:
So, you just plug the adapter cable into ANY? USB port on your computer and plug the KVM cable for that computer into the PS/2 ports on the other end of that adapter cable and it works? Yes, that has been my experience. Currently I have it set up on a computer running XP, but I have had similar success with Vista and 7. It is connected to an old IOGear MiniView KVM switch. I can only vouch for that particular adapter (with the black USB plug and silver wires). I haven't tried any of the others. |
#7
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PS/2 KVM switch
On Mon, 03 Feb 2014 11:32:52 -0600, Greg Berchin
wrote: I can only vouch for that particular adapter (with the black USB plug and silver wires). I haven't tried any of the others. I've have troubles at times adapting a PS2 keyboard with USB adaptors (also the couple oddball keyboards scenarios even though perfectly pair-mated to a PC's I/O ports). Wouldn't consider anything but a USB keyboard now. (Love an excuse to buy a top-notch $100+ gaming keyboard off newegg on half-price sale. ...my Focus keyboard is one tough old tank.) |
#8
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PS/2 KVM switch
Greg Berchin wrote:
On Mon, 3 Feb 2014 09:24:52 -0800 (PST), NestorK wrote: So, you just plug the adapter cable into ANY? USB port on your computer and plug the KVM cable for that computer into the PS/2 ports on the other end of that adapter cable and it works? Yes, that has been my experience. Currently I have it set up on a computer running XP, but I have had similar success with Vista and 7. It is connected to an old IOGear MiniView KVM switch. I can only vouch for that particular adapter (with the black USB plug and silver wires). I haven't tried any of the others. My only word of warning would be, the silent change over from the old design, to a newer design. The Chesen chip used in the old design, is out of production. There is a second chip of similar design, might even be footprint compatible. What we don't know, is if the firmware that manages the thing, has the same fit and finish. Paul |
#9
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PS/2 KVM switch
OK, lets say I try using a USB to PS/2 adapter cable and it doesn't work. In that case I'd be likely to tell myself that there's no standing in the way of progress and both PS/2 ports and PCI cards are a thing of the past. In that case, I'd probably end up buying a 4 port USB KVM switch.
The question is: Do I buy one with DVI, HDMI or VGA video input ports? I want to be able to watch videos in HD on a 1080P TV set or computer monitor, and I was told that VGA theoretically can handle High Definition video. The other thing is that there will ALWAYS be VGA ports on video cards because of the huge installed based of business computers that don't need High Definition video to do word processing, spread sheets and other business applications. I understand that if I go with DVI or HDMI, I can convert to the other with just a cable adapter. But, if I do go with VGA, does that pretty much rule out watching videos online in High Definition? |
#10
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PS/2 KVM switch
NestorK wrote:
OK, lets say I try using a USB to PS/2 adapter cable and it doesn't work. In that case I'd be likely to tell myself that there's no standing in the way of progress and both PS/2 ports and PCI cards are a thing of the past. In that case, I'd probably end up buying a 4 port USB KVM switch. The question is: Do I buy one with DVI, HDMI or VGA video input ports? I want to be able to watch videos in HD on a 1080P TV set or computer monitor, and I was told that VGA theoretically can handle High Definition video. The other thing is that there will ALWAYS be VGA ports on video cards because of the huge installed based of business computers that don't need High Definition video to do word processing, spread sheets and other business applications. I understand that if I go with DVI or HDMI, I can convert to the other with just a cable adapter. But, if I do go with VGA, does that pretty much rule out watching videos online in High Definition? If you check the Wikipedia articles on DVI or HDMI, they'll give you some idea on resolution limits there. Worst case, single link DVI does 1920x1200 @ 60Hz with reduced blanking. Which is slightly more than HD. LCD monitors support reduced blanking, because they have no "beam" like a CRT used to have, and can go from right to left (retrace) in no time at all. The old CRTs, needed a blanking interval for moving the beam. The tightened up format for the signal, means a higher resolution can be sent. I think VGA on video cards, has done 2048 or 2560, in other words, a 400MHz DAC spans the region of interest. In terms of settings, the VGA video card can then do the 1920x1080 you want. The question then comes, about propagation characteristics, cable length, and "effects". VGA is analog. Every defect in analog transmission (reflections, crosstalk, image softening with distance) comes into play. At least on the old CRT monitors, the higher the resolution you selected, the more you could see things like ghosting, which could either be a connector effect (reflections) or something to do with cabling. When a KVM handles VGA, it might not necessary have the same bandwidth spec, as the 400MHz DAC in the video card. Generally, it's inferior to that. The KVM should indicate, what maximum resolution you could use, due to the analog bandwidth limitations through the KVM video path. OK, so what happens with digital transmission ? No reflection effects, at least at first. When the cable gets long enough, the digital transmission error rate is no longer zero, and speckles of colored snow show up. If the cable is made longer, the amount of snow increases. Eventually, the monitor loses sync, and if a super-long cable is connected, you'd get something like the blue "loss of signal" type screen (or the OSD flashes some message up on the screen). The KVM needs to "regenerate" the signal. So digitally, it doesn't do much with the signal. If it sees a 1 on the input cable, it puts a 1 on the output cable. It shouldn't have an issue with bandwidth, unless the chip used inside, is incompetently made. You check the specification of the KVM, to see which DVI or HDMI standard it is compliant with, to understand what limitations it might have. For example, early generations of digital video run at a "clock rate" of 165MHz, whereas a later one does 340MHz. These rates affect the max resolution the cable carries. As the rate goes up, the max length of cable might come down. So if you sent a signal to an Apple 30" Cinema display, perhaps the cable you could use wouldn't be as long as if you were driving some 1024x768 display with the same KVM. That's the impact of the cable, on the ability to get the digital signal through the cable, interference free. As long as you're not seeing snow though, the image is "perfect". Unlike with VGA, where even a zero length cable, might not look good. The KVM might make a mess of a high res VGA signal, and the companies that make KVMs aren't exactly oozing a sense of ethics and fair play when they sell stuff. So if I was a gambler, and wanted to improve my odds, I'd go digital. After reading up, on what people get away with, when buying cabling for DVI or HDMI. While it's possible to buy additional hardware to improve any situation, most people just want a KVM plus limited_cable_length to work without additional outlay of cash. The customer wants to pay $80 for their KVM, and the KVM maker is determined to make poo for $80. Your job is to catch them, by reading the reviews for the product, before you buy it. And so the battle goes. Part of the battle is specs, and part of the battle is detecting honesty. My reference to "incompetently made", I should expand on that a tiny bit. When DVI first came out, the 165MHz so-called "clock", refers to the pixel clock. The byte of data for each pixel color, is transmitted serially. The actual cable rate is 1650MBaud. Early GPU chips, some of them (incompetent) could only do 1350. The GPU manufacturer, would then artificially limit the resolution options in the video card driver, to hide what they'd done. The thing was, when that flavor of I/O came out, it was intended for 622 meg operation, and over a period of a couple years, the chip makers were able to push that several times over. But at least a few GPU models, were caught with their pants down, on the bandwidth required to send the digital signal (pad driver). And that's the incompetent part. If the video card said "I am compliant with DVI spec 1.0" or something, that would have been a lie. If there was an organization that had been certifying DVI devices, it would have rejected those products, when they were examined on a digital scope with eye diagram capability (Tektronix). I'm hoping, that just about any company making chips like that today, won't be doing that, and all the chips will meet their spec. Doing 340 on HDMI is pretty demanding, and that is presumably a tough target to meet. Let's just hope the fab that makes KVM chips, isn't in some third-world country :-) There are older fabs, that make ancient chips (RS232 UARTs, parallel ports), where the fab would be unlikely to be able to handle full HDMI rates. Paul |
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