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geekhack Community => Other Geeky Stuff => Topic started by: bigpook on Fri, 01 August 2008, 05:12:05

Title: KVM advice
Post by: bigpook on Fri, 01 August 2008, 05:12:05

I have a Cables to Go 4 port KVM. It has 3 usb ports on the front and can be operated manually or via hot keys on the keyboard. The hot keys are 'scroll-lock, scroll-lock, (1,2,3,4).

I am having issues with it when I use my IBM model M spacesaver. It happens at least once a day, sometimes more. I will lose the hot key, actually, it will change to 'Ctrl, Ctrl ( 1,2 3,4). Which is annoying but I can live with it. But worse yet the keyboard will eventually fail to register at all. No key strokes or anything. I have to reset the KVM and disconnect/reconnect the keyboard cable to fix it.

I am now back on my Unicomp keyboard which has no issues at all with the KVM.

At this point, I am thinking the KVM does not like my Model M.

Is anyone here using a Model M spacesaver with a KVM? If so let me know, if you would, how its working for you. And which model/type you are using.
Ideally, it would be a 4 port.

Title: KVM advice
Post by: itlnstln on Fri, 01 August 2008, 06:06:14

I used my M with a generic USB KVM I got from Monoprice.com (2-port with detachable cables, not the built-in type).  I used another generic USB-PS2 adapter from Monoprice as well.  I had no issues except for an occasional "reset" where the keyboard acted like it was being unplugged and re-plugged back in, but that only happened about once a day or so.  It might be that the generally higher power requirements of the Model M might be jacking with the KVM somehow.

Title: KVM advice
Post by: iMav on Fri, 01 August 2008, 08:16:32

Which PS2/USB adapter are you using?  I used my Model M mini on a couple of different USB KVM's (one of them a pricy DVI model), and didn't have any issues.  But I was using this PS2/USB adapter:

(http://www.uhhh.org/~lherzog/blog-images/usb-adapter.jpg)

Title: KVM advice
Post by: bigpook on Fri, 01 August 2008, 16:43:51

Quote from: iMav;7047

Which PS2/USB adapter are you using?  I used my Model M mini on a couple of different USB KVM's (one of them a pricy DVI model), and didn't have any issues.  But I was using this PS2/USB adapter:

Show Image

(http://www.uhhh.org/~lherzog/blog-images/usb-adapter.jpg)

I have that very same adaptor, however the KVM is ps/2. Maybe its the voltage requirements of the Model M.

Title: KVM advice
Post by: bhtooefr on Sat, 02 August 2008, 15:34:10

Model M requires +5 VDC, just like any other keyboard. ;)

It's the amperage requirements.

There is the resistor mod... alternately, you could always come up with a second source of +5 VDC for the keyboard (maybe a USB cable for supplying power?) and then the KVM should be fine.

Another thing you can do: Some motherboards and KVMs provide more power on the mouse port than the keyboard. Then, some actually don't care what port you plug what into. So, if your KVM supplies more power on the mouse port, and doesn't actually care where the keyboard is plugged into, then try that.

Title: KVM advice
Post by: bigpook on Sat, 02 August 2008, 17:08:29

I noticed the unicomp keyboard is losing its scroll lock, scroll lock (1,2,3,4) to swap computers, sometimes it jumps to the numlock key, sometimes it jumps to the ctrl key.

If I reset the KVM it fixes it. The Model M will behave the same way with the added bonus of just locking up. I need a better KVM.