Possibly good KVM Switch for OS4 & Windows

I've been using a StarTech SV231UADVI for a long time, but making it play nice with OS4 meant hacking my KickLayout file, so I couldn't really recommend it to other Amiga users. Unfortunately a firmware update screwed it up (for my lovely Apple keyboard), and StarTech are unable to revert the firmware, so I was finally forced to look for a replacement.

I've just bought a StarTech SV231DVIUA (yes it's a different model & no that's not a typo) off eBay. To avoid confusion, the actual model is here:
http://uk.startech.com/Server-Managem ... -Audio-USB-HUB~SV231DVIUA

This one seems to work without hacking OS4's Kicklayout file, so I thought I'd mention it here before I forget. It's by no means perfect, but so far it seems the least-bad KVM Switch I've tried. Issues that I've noticed:

* I had to add one line to my British KeyMap to get OS4 to recognise one key (near the Enter key) on my Apple keyboard. You could live without doing this, but the change is pretty easy to make, and it might not be necessary on a non-Apple keyboard. There's also an Apple-specific key on the NumPad which OS4 doesn't see, as well as F13 to F15 (which might be fixable by editing the KeyMap, since Windows does see them).

* There are also a few Apple-specific keys that neither OS4 nor Windows see (basically F16 to F19, which my old KVM Switch did handle, and the Eject key, which has never worked). If you have a non-Apple keyboard then you can ignore this.

* The keyboard is virtualised (so the computer you switch to does NOT have to re-recognise it), but the mouse is not (unlike my old KVM Switch), so you'll find OS4 & Windows act like you've just plugged the mouse in when switching to them. This does not cause me any problems, but when I've tried a KVM Switch where the keyboard wasn't virtualised (i.e. it gets connected to the computer I switch to) Windows always took forever to recognise the keyboard and/or mouse (very frustrating). So there's a small possibility you might have problems with the mouse when I don't.

* While this KVM Switch can be customised (to a lesser degree than my old KVM Switch), those customisations are lost when you turn the power off. So the customisations are basically pointless unless you leave it plugged into power the whole time (I don't). My old KVM Switch allowed you to completely disable audio switching (i.e. do that manually), but this one does it in a less good way & the customisation is forgotten at power off... but I can live with this.

* I've occasionally had a key appear to get "stuck" (on both Windows & OS4), such that it keeps repeating until I press it again. This may be specific to my Apple keyboard, and I'll have to see how annoying it becomes. I do intend to pester StarTech's support about it, but I don't hold up much hope. (There doesn't seem any indication firmware updates are supported - another way my old KVM Switch was superior.)

* If I boot AmigaOS4, while using Windows, then OS4's (optional) automatic detection of monitor settings causes it to think my monitor supports 1920x1200 resolution, but thankfully my fancy monitor still manages to display it (but a bit hard to read), and anyway a soft reboot fixes that. Never had this problem with my old KVM Switch. I *suspect* this issue is due to me having the expensive HighRes version of this Switch (see below), so you might be OK with the normal version I linked to at the start of my post. Or you could disable automatic monitor detection. Or not boot OS4 while using Windows!

P.S. BEWARE that I actually have the rather more expensive (when new) SV231DVIUAHR, but I imagine it is basically identical in behaviour to the SV231DVIUA. Don't blame me if it isn't!

After further testing, including using a normal Windows keyboard, it looks like I canNOT really recommend this KVM Switch after all:

The virtual USB keyboard implementation seems pretty terrible, as occasionally it fails to notice (or transmit) a key up or down event. Which means that occasionally a key press isn't seen by the computer, or (rather worse) it'll think a key is still held down when it isn't (leadddddddddddding to something like that or worse if it's a qualifier key like Shift or Ctrl). I intend to chase StarTech about this, as it seems a ridiculous flaw.

@ChrisH

I tested some KVM Switchs, from DIGITUS and others. All make the same error , sometimes repeat letters, others don't send the letter etc, etc.

The only that works fine it's an old ATeen KVM, that give a friend for a few days. Whit this all works fine.

I call her tomorrow and give you the exact model. I only know that the new version it's very, very expensive.

Virginio

@RIBDEVIL Quote:
OK, thanks.

My old Startech KVM Switch did not have this problem, so it was almost perfect (except for an issue with OS4 that was fiddly to work-around).

@ChrisH

Quote:

I have the same problem with my ATen CS1784A. It periodically causes key events to be missed, with the same results that you report. Even worse, when switching to/from Windows, it takes half a minute or so before Windows responds to the keyboard and mouse. In my case it's much better behaved on AmigaOS, although still not problem free.

It could be that it doesn't work well with the wireless keyboard/mouse combo that I have, but it's pretty annoying.

So I'm also on the lookout for a KVM that just works.

Hans

@Hans

That's disappointing. I've had NO problems at all with my ATEN CS1734A. It works great mixing PS2 Keyboard and Mouse (AmigaOne XE), with USB (Sam440, X1000, Windows box).

I'm considering the CS1758 for an 8-Port solution, so I hope it doesn't have any trouble.

@Hans

I'm using an Aten CS682-AT KVM switch here ATM that seems to work OK for me (I've had it for about a month). This was the cheapest KVM I could find that had DVI and USB support, all others were about twice as expensive or more.

Before this I was using an Aten CS62U (VGA and USB) KVM. This one worked OK too, although sometimes the scroll lock key got stuck on the Amiga side causing U-boot booting to get interrupted.

StarTech suggested the following KVM Switch as a better alternative (at an eye-watering RRP of £250, but Amazon sells it for 'only' £150 and PC World Business for £142) :
http://www.startech.com/Server-Manage ... -with-Cables~SV231DVIUDDM

The key point is that it uses "Dynamic Device Mapping" for USB keyboard & mouse, such that both computers think the USB devices are still connected, but the USB device directly communicates with the active computer (rather than being passed through keyboard & mouse emulation that might not support all features & might be buggy) :
http://en.wikipedia.org/wiki/Dynamic_device_mapping
http://connectpro.com/technology/usb-ddm/

This sounds like the Holy Grail of KVM Switching, as it should provide 100% compatibility & fast switching.

StarTech's KVM Switch also seems to do some magic with DVI's DDC for faster monitor switching, but I manage fine without that.

And a downside is StarTech's KVM lacks audio switching.

So the real question is: Are there any cheaper KVM Switches which use Dynamic Device Mapping (DDM)? (And support audio!)

edit: Looks like DDM is ConnectPro's patented technology, and StarTech's device is not much more than a rebadging of ConnectPro's one:
http://connectpro.com/product/ud-12-plus/

So probably they aren't going to be much cheaper...

CMP KB,VGA,Mouse -made in China.. Now a nice HP monitor but had to put DVI in PC & VGA straight to the monitor allthough the DVI started to work in an update. The KVM not in the VGA and mouse stopped also so maybe a fault, and the screen settings never where fine.

Solution: Another Logitech mouse (White for the XE and Black for the Win) and the two inputs in the monitor from each own. Hopefully this Logitech (old pc style) kb works with the switch a bit longer.

Should clean up the wire area and straighten the jungle. Only vacuumed once in a while.

The switch worked in the VGA times and was very cheap..

Not making any arranges until something goes wrong..

I have Aten CSI782, Its a USB mouse/keyboard, DVI, and audio switch, it also has extra USB port that can be used to connect USB printer or something like that.

It works fine with standard mouse and keyboard, but does not work with gaming mouse from Logitech, it uses some kind of mouse & keyboard emulation and it's not compatible.

"Scroll Lock" is used for monitor switching, this is problem as this key is the help key in AmigaOS4.1, and "Scroll Lock" key is also used to get into the kickstart menu, so its a drawback.

@LiveForIt

Quote:

Not a problem if you reassign it. I have the scroll lock and menu keys switched around here using my AmigaKeyRemapper program.

Using scroll lock for switching is pretty common for KVMs BTW.

@logicalheart

Quote:
It could be that the KVM doesn't work well with my Logitech wireless keyboard + mouse combo, and that it would work just fine with a generic keyboard and mouse. Still, ATen had received complaints about this from others, and I had hoped that they'd fix it in a future firmware update.

Hans

@LiveForIt Quote:
Many thanks for that report. ATen seem to do a non-surround-sound version, which I assume will work similarly well:
http://www.aten.co.uk/products/KVM/De ... 84%A2-Switch~CS1762A.html
(Amazon sell this for £120.)

EDIT: The (surround-sound) CS1782A is better in that the keyboard & mouse input are at the back of the unit (rather than on the front of the CS1762A):
http://www.aten.co.uk/products/KVM/De ... 84%A2-Switch~CS1782A.html
(Amazon sells this for £140.)

It's odd that Hans has keyboard issues with his ATen CS1784A, which also appears to be similar. Maybe it's down to his Logitech wireless keyboard + mouse combo, like he suggests.

@LiveForIt, @Hans
Do your Aten KVM switches allow the audio to be changed separately (from everything else)?

@salass00 Quote:
Many thanks for that report. This appears to be the one you mention:
http://www.aten.co.uk/products/KVM/Ca ... DVI-KVM-Switch~CS682.html
(Amazon sell this for £50.)

I also discovered that ATen sell this one which uses a weird custom cable (yuck) :
http://www.aten.co.uk/products/KVM/De ... DVI-KVM-Switch~CS72D.html
(Amazon sell this for around £150 but stock seems very limited, so I guess it's discontinued.)

@ChrisH Quote:
One possible solution would be a separate (phono) audio switcher, for an extra £10 or so. Both of my existing StarTech KVM switches have the option to change the audio separately from everything else, which I find highly useful, so this could be a good solution for me... but a bit of a risk since no-one else here has yet tried it.

@ChrisH

Quote:
Yes, audio can be switched separately on the ATen CS1784A. Basically, if you briefly press the button for another input, then the monitor mouse & keyboard will switch. Hold down the button for a second or two, and the audio will be switched too.

Hans

@Hans

That's strange, I believe that on mine a brief press switches only the monitor (to quickly check e.g. the progress of some running job, while a longer press switches USB (mouse/keyboard) and audio as well.

Well, actually on my setup the short press switches also my wireless mouse, because I've connected the receiver to the front USB port, while the keyboard (cabled) is in the rear keyboard USB socket.

This is the case both on the CS1784A and the CS1764A, AFAIR.

Best regards,

Niels

@Hans Quote:
Have you checked recently? I see there was a firmware update on 27th August 2014 which mentions "Enhanced compatibility with Logitech K400r".

@ChrisH

No, I haven't tried that one because I stopped checking for firmware updates a while ago (not much was happening). I'll check it out. Thanks for letting me know.

EDIT: Just tried upgrading, and: "firmware upgrade failed."

Hans