Using a KVM switch with a Macbook

January 7, 2008 1:38 AM

First time using a KVM switch. PS/2 keyboard,mouse, Macbook and Desktop. Need help :( Full details inside.

So I bought the following pieces of computer equipment on Boxing Day:

- 22" LCD monitor
- PS/2+VGA KVM Switch
- Apple MiniDVI - VGA adapter
- A strange USB to PS/2 adapter - it has two inputs (one for a keyboard, one for a mouse) and a USB output

This works beautifully with my desktop, which requires neither the MiniDVI-VGA adapter nor the USB to PS/2 adapter.

However, it fails to work very well with my Macbook. I was able to get the USB-PS/2 adapter to work once, and it's failed ever since. When it did work, the mouse was laggy and jumped around. Also, this may just be because I was discouraged about the USB adapter, but it seems that the monitor is very blurry as well.

Any ideas on a better way to hook this up? New equipment is an option, but I'd prefer to deal with what I have.

posted by mebibyte to computers & internet (3 comments total)

My two cents: Using a PS/2 KVM is a mistake. I'm not a Mac guy, but most PCs I've used (Windows/Linux) detect the presence of a PS/2 mouse when they start up (or when the X windowing system starts). This means PS/2 KVMs tend to have mouse emulation built in, so that computers that aren't selected still detect a mouse.

The issues: how good is their mouse emulation? Do they emulate a 2-button, 3-button, 2-buttom + wheel, etc. mouse? What about all the nice features of my mouse? Does my computer support the mouse protocol they're emulating? This is my primary reason for using a USB switch. Computers with USB support are accustomed to USB devices being plugged and unplugged, and handle it nicely (although you have to wait 1-2 seconds while they are detected).

The VGA issue is probably a result of running a high resolution (22" monitor means you're probably at least 1600x1050, right?) over an analog connection not really intended for such resolutions. Add to that the presence of the switch and you've got signal degradation and more room for interference. I deal with the fuzziness on my VGA setup (24" LCD at 1920x1200), but I'm planning to upgrade to a DVI KVM soon (if I ever find one that gets good reviews).
posted by knave at 3:09 AM on January 7, 2008

A Mac will pretty much never work with ps2 mice and keyboards, even with a USB adapter.
I purchased a usb KVM and have not tried it out yet since I've gotten a macbook and a USB keyboard (I used to have ps2). You could try to return the KVM and USB adapter.
Go on newegg.com and grab a less than $20 kb/mouse set from logitech (usb only) and try to get a USB kvm from there that says it is mac compatible.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817403047
http://www.newegg.com/Product/Product.aspx?Item=N82E16823126018
Those two items should get you going.
posted by ijoyner at 7:22 AM on January 7, 2008

You may able to do what you want purely in software - take a look at Synergy:

http://synergy2.sourceforge.net/

This lets you use one keyboard and mouse to control multiple computers - a server runs on one of the machines, and a client on each of the others, and mouse and keyboard events are sent across the network when you move the mouse off the side of one screen and onto the next. I use it, and I find it more useful than a KVM switch for my purposes.

It obviously won't help with sharing a monitor, but your Macbook presumably has its own display anyway.
posted by siskin at 7:41 AM on January 7, 2008