Let's talk about KVM switches

Message

edcard · #1 Post by **edcard** » Wed Nov 17, 2004 2:14 pm

I want to share a keyboard, mouse and LCD display between my old desktop PC and my new T42p. The laptop is attached to a Mini-Dock which provides DVI output as well as PS/2 and USB ports. At present the keyboard and mouse I use connect to the desktop unit via PS/2, but I could switch to USB devices if desirable. The LCD display uses a DVI interface.

So I've been looking at KVM switches which support DVI. I'm leaning towards a Startech unit which supports DVI and PS/2, and would therefore support the peripherals I currently own. I understand that some KVM switches have problems with Thinkpads, but it is not clear to me whether this is a result of not having enough power (for switches w/o their own power supply like the Startech), or not being able to deal with extra signals on the PS/2 interface that apparently the Thinkpads use, or a separate reason.

I've seen units that claim to be "Thinkpad compatible" but they are usually very expensive and/or do not support DVI. I'd like to keep my costs to $150 or less, not including cables.

So, does anyone have experience with using a Thinkpad (T42) with DVI-PS/2 KVM switches, or DVI-USB switches? What are the issues that affect compatibility between KVM switches and Thinkpads? Do the less expensive KVM switches (Belkin and the like) work well or at all?

Thanks in advance.

gruen · #2 Post by **gruen** » Wed Nov 17, 2004 5:23 pm

I know that my kvm (iogear ps2) wouldn't allow my tp to boot for some reason off the dock... do a search and find out about that; maybe they fixed it.

skanky · #3 Post by **skanky** » Wed Nov 17, 2004 7:02 pm

i have a cheapish 2 port belkin KVM (the one with non removeable cables) and it doesnt let me switch to the TP if its going through my docking station.

never had any problems switching with my old toshiba lappy.

edcard · #4 Post by **edcard** » Thu Nov 18, 2004 8:55 am

Thanks for the info. Do these two switches (Belkin and iogear) work without the dock?

muffd · #5 Post by **muffd** » Thu Nov 18, 2004 12:09 pm

Ed, I have an IOGear 2 port ps2 also and cannot boot the T40 when connected to the mini dock. I tried using the VGA and DVI connector and failed. I heard at work that you could try using a ps2 to usb adapter for the mouse and keyboard. Failed there also. The KVM works fine when connected to regular pcs. I also used the mini dock just with an LCD, external keyboard, mouse and then was fine.

Please post your findings if you figure this out. I would love to hook up my T40 with my desktop pc and just share a monitor.

monty cantsin · #6 Post by **monty cantsin** » Thu Nov 18, 2004 12:45 pm

edcard wrote:I want to share a keyboard, mouse and LCD display between my old desktop PC and my new T42p.

I know, that's not exactly what you're searching for, as it doesn't share the display and requires all systems to be turned on, but anyway, others might be interested in this:

There's a free software, "Synergy", which lets you share keyboard and mouse (and clipboard) on different computers via a network connection. This way, you can row up your desktop computer and notebooks and use them almost like a multi-monitor system (applications cannot be dragged from one system to another, of course).

http://synergy2.sourceforge.net/

If you don't use applications that require very quick display updates (like video editing etc.), a quite convenient software-only solution could be the Remote Desktop functionality in XP Pro. I'm using that quite often to work on my notebooks that are in a different room via WLAN, runs quite well (display updates in Remote Desktop are much quicker than with ordinary VNC software that doesn't utilize special video drivers, almost real-time under most circumstances).

muffd · #7 Post by **muffd** » Thu Nov 18, 2004 12:56 pm

Has anyone here tried using USB KVM switches? I was thinking of this as another alternative as well.

Also, those having problems or those that get this to work, please post what brand/model KVM you are using so we know what to get/not get.

Thanks

jank0003 · #8 Post by **jank0003** » Thu Nov 18, 2004 1:56 pm

I use the iogear USB/monitor plug KVM switch with my T41 and it works just fine. I got it for $30 on sale at Compusa a while back; they usually sell for $40. I'm on the verge of buying another one for home use; it is that nice to use a regular keypad and monitor with my laptop.
janx

muffd · #9 Post by **muffd** » Thu Nov 18, 2004 3:20 pm

jank0003 wrote:I use the iogear USB/monitor plug KVM switch with my T41 and it works just fine. I got it for $30 on sale at Compusa a while back; they usually sell for $40. I'm on the verge of buying another one for home use; it is that nice to use a regular keypad and monitor with my laptop.
janx

Hi
Can you post the model # you used? I would like to check this out.

Thanks

Is this the one that you used?
http://www.compusa.com/products/product ... pfp=SEARCH

jank0003 · #10 Post by **jank0003** » Thu Nov 18, 2004 3:35 pm

Hi
Can you post the model # you used? I would like to check this out.

Thanks

Is this the one that you used?
http://www.compusa.com/products/product ... pfp=SEARCH
_________________

Yup...

The one at compusa: The IOGEAR MiniView Micro Mfg Part #: GCS52U is the one I use. One of my friends has a SONY and another a DELL and they are both also happy with this KVM; I followed their recommendation.

I recommend buying this item at a retail store. The first one I bought had a MFG defect and needed to be returned. The second one has been just fine for a month now. Read through the reviews online and you will find that for some reason KVM switches seem to be inherently unreliable... My friends have been using their IOGEAR for well over a year with no problems. If you get a good one they seem to stay good...

janx

muffd · #11 Post by **muffd** » Thu Nov 18, 2004 8:13 pm

It worked!! I bought the KVM mentioned above and can now use this with my mini-dock. Guess it's time to sell my older IOGEAR!

edcard · #12 Post by **edcard** » Sun Nov 21, 2004 12:00 pm

Great! Now we know of a KVM that works with and without the dock.

As I want to use DVI, I ordered a Linkskey unit to try it out. I'll report here once I've tested it.

edcard · #13 Post by **edcard** » Sat Dec 11, 2004 2:51 pm

Ok, I finally got the LinksKey KVM to work. This is a two-port PS/2 DVI KVM switch. When I first tried to use it, I had the same problems reported by others: ThinkPad wouldn't boot or wouldn't recognize the mouse, etc.

I finally purchased a $2 PS/2 to USB Adapter and used it to connect the PS/2 cables from the KVM switch to one of the USB ports on the Mini-Dock. Everything works fine now, and I can switch from the desktop to the laptop and back w/o problems.

JohnDrake · #14 Post by **JohnDrake** » Sat Dec 11, 2004 7:00 pm

Changing the boot up mode from "Quick" to "Enhanced" solves a lot of KVM issues, as additional time is applied to detect keyboards and pointing devices. This can be done in the CMOS settings, press F1 prior to booting the OS.

lvlolvlo · #15 Post by **lvlolvlo** » Sat Dec 11, 2004 10:19 pm

I have a cheap $20 IOGear switch that I bought from buy.com that lets me use VGA and PS/2 KB MS

I use it sometimes with my thinkpad and it works flawlessly.

edcard · #16 Post by **edcard** » Sat Dec 11, 2004 11:54 pm

Are you using a dock or port replicator, though?

That's when one runs into problems.

bcrooker · #17 Post by **bcrooker** » Fri Dec 24, 2004 11:10 am

I have a T42p with the Port Replicator II and an Iogear 4 port PS/2 KVM and was running into the same problems as discussed on this forum. I tried the following items without help:

1. Used a PS/2 -> AT converter and an AT -> PS/2 converter in-line (suggested from Iogear web site).

2. Used a PS/2 -> USB convert to plug mouse cable into USB plug on Port Replicator.

I was almost to the point of simply ordering a new mouse ($16 for the mouse sounded better than $130 for a new KVM) when I found the following product from Iogear.

http://www.iogear.com/main.php?loc=prod ... m=GUC100KM

I just got it this morning and it seems to work great. I purchased this item from TigerDirect for $19.99 (plus shipping).

Hope this helps.

danparkcityut · #18 Post by **danparkcityut** » Wed Mar 30, 2005 6:38 pm

And I thought it was just me...

I have a new (to me) T30, 2366-81U, 02K8668 dock, and Switchview PS2/HD15 (with USB device switching, for my printer). Sometimes I get it to boot, usually not (it just hangs at the IBM pre-boot screen).

I've done the bios change from "quick" to "diagnostic", but then I don't even get the IBM pre-boot screen, just a screen one shade of grey from dead black (and hanging).

I'm glad I kept my trusty old 600X, as it played nicely with this same setup in it's old dock! In fact, I might have a 'still under warranty' T30 for sale soon if the IOGEAR adapter doesn't work.

I might even include the Intel Pro 2200BG I got for this T30 and apparantly can't use!

Stay tuned

danparkcityut · #19 Post by **danparkcityut** » Sun Apr 03, 2005 11:56 am

How about that?

My PS/2 to USB adapter came in yesterday. I've got the T30 in it's dock and the adapter connected to the dock and KVM cables.

It actually works (well, first boot anyway).

Thanks for the tip on this idea folks!

Now, on to the Intel Pro 2200BG / no-1802 task...

johnmsch · #20 Post by **johnmsch** » Wed Mar 08, 2006 10:38 am

Wow. What a great resource! I found this forum while doing a Google search, looking for a way to get my new KVM switch to work with my IBM laptop and docking station.

I have a T42 and a ThinkPad Port Replicator II. I have 2 other machines, and wanted to put them all on a KVM. Tried a couple of the Belkins, but they are absolute garbage. You loose the keyboard and/or mouse when switching between machines (among a long list of other problems), and its not cheap!

After reading numerous reviews about IOGear's KVMs, I gave one a try. Its the PS/2 version:
http://www.newegg.com/Product/Product.a ... 6817107419
I assumed that the keyboard and mouse PS/2 ports on the back of the Port Replicator would work, but they did not. I plugged the keyboard and mouse directly in to the docking station and they worked fine. IOGear support told me there was a problem with IBM and/or the docking stations. Based on notes I found here, I went out yesterday and bought a USB to PS/2 adapter at Fry's:
http://www.cablesunlimited.com/products ... code=I1028
It works perfectly!

When I first booted the laptop using this adapter, it took a minute for it to recognize the mouse (using a cordless Trackman wheel). Again, based on a note I saw here, I had already changed the BIOS "Boot Mode" parameter from "Quick" to "Diagnostics" (with 2gig of memory, that initial memory test takes about 3,000 years!). Once it picked up the mouse, it worked fine. This morning, I changed the BIOS back to "Quick", and it still works fine. I'm a very happy guy!

I still can't belive how good this works for the price. The Belkin setup was about $200 ($110 for KVM, $30 for each cable set), while the IOGear setup was only about $60 ($55 for the KVM, $6 for the USB to PS/2 adapter).

Thanks again for everyone's input into this thread and forum!!!!

Dead1nside · #21 Post by **Dead1nside** » Tue Jul 25, 2006 2:37 pm

Could anyone recommend a KVM that will work with a D-Sub monitor, USB Mouse and Keyboard? Since IOGear do not sell in the UK. Thanks.

chan_man · #22 Post by **chan_man** » Wed Jul 26, 2006 12:41 pm

I have had great luck with a Cybex Switchview KVMs, both the 2 port and the 4 port. These are the standard VGA and PS2 connections. The mice I use are USB and the USB/PS2 adapters that comes with the mouse will work. These KVMs are not cheap though..

Dead1nside · #23 Post by **Dead1nside** » Wed Jul 26, 2006 1:29 pm

Thanks for that, but they also from a quick googling look like they don't really sell in the UK.

fritz_the_blank · #24 Post by **fritz_the_blank** » Wed Aug 02, 2006 11:42 am

If you don't need high performance from your secondary machines, you can try what I have done.

I have a T42 attached to a 21" widescreen monitor, and I use the T42 as my keyboard and pointer. I have a second laptop that I use for running processes (downloading large files, burining DVD's and etc.).

Rather than buying a KVM, I set up a remote desktop connection so that I could control the secondary laptop from my T42.

Over a 100 base T network connection, it works remarkably well with very little latency. The only issue that I have come accross so far is that if I play a video on the secondary machine, the result is so choppy as to be unusable. I expect the same would be true with gaming as well.

If you needs are modest like mine, however, this approach works well and doesn't cost a cent.

Let's talk about KVM switches

Let's talk about KVM switches

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