HDMI KVM Specs.

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As previously notedI have 2560 x 1080 "extra wide" screen.

 

I would like to get a KVM[1] so that I can switch it between 2 computers.

 

KVMs for  1920×1080 HDMI are common, but not so much for the extra width.

 

So the question is: would a  1920×1080  switch be likely to work with the 2560 width? In the old analogue (VGA) days, you could get away with pushing the specs a bit - but does that work with digital? Would 2560 be just taking it too far anyhow?

 

[1] KVM = Keyboard / Video / Monitor switch

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Last Edited: Tue. Sep 22, 2020 - 11:49 AM
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Is RDP not  enough?

RDP - Remote Desktop Protocol

 

"Dare to be naïve." - Buckminster Fuller

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the devices are on the same desk; not looking for remote access.

 

also not looking to "occupy" one device with accessing the other(s).

 

they may not all be PCs ...

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Last Edited: Tue. Sep 22, 2020 - 07:32 AM
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An alternative, if you have space on the desk for a second display, is keyboard/mouse sharing over the network using something like Synergy.

 

Steve

Maverick Embedded Technologies Ltd. Home of Maven and wAVR.

Maven: WiFi ARM Cortex-M Debugger/Programmer

wAVR: WiFi AVR ISP/PDI/uPDI Programmer

https://www.maverick-embedded.co...

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An acquaintance of mine is CTO of this company: https://www.displaylink.com. Their focus is HDMI over USB.

This reply has been marked as the solution. 
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I have a possible solution as I ran into this as well.  I tried 'pushing' a KVM past its posted limits and it did not work >Video tearing, and warping<. 

 

My solution was to replace my two monitors with high resolution ones that could support the higher H/V specs.  They are also dual input screens as well so when I want to use the other computer, I hit the source select on the screens to switch to the other input(s).

 

For the Mouse/Keyboard I use Logitech Unifying  products.  Essentially these devices can be inter-paired.  On the mouse, or keyboard theres a button that selects receiver 1, 2, or 3.  On the computer(s) you install teh unifying software and set the software as 1, 2, or 3.  The software then does something to the little bluetooth receiver you plug into the USB port and now you have one keyboard/mouse for up to 3 machines.

 

Yes, I have to press three buttons to switch between computers.  It takes seconds to do, and I am fine with that as I do not have another device on my desk, and the associated headache of wires to manage to go with it.

 

 

YMMV.

 

JIm

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

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Last Edited: Tue. Sep 22, 2020 - 11:34 AM
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jgmdesign wrote:
I tried 'pushing' a KVM past its posted limits and it did not work >Video tearing, and warping<.

Thanks - I thought that might be the case.

 

Trouble with this is that you can't just "try it and see".

 

dual input screens as well so when I want to use the other computer, I hit the source select on the screens to switch to the other input(s).

Yes, that's what I'm doing at the moment.

 

 

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
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Try looking into the Logitech Unifying keyboards and mice.  Worth every penny.

 

JIm

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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awneil wrote:
Trouble with this is that you can't just "try it and see".

 

SURE YOU CAN!!  Buy a few KVM's off of Amazon and return them if they don't work - LOL

 

Jim

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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jgmdesign wrote:
return them if they don't work

but if they only say they'll work to 1920x1080, I can't really complain that they "don't work" at  2560 x 1080

 

Or am I just being too honest ... ?

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
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Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
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awneil wrote:

found one: https://www.amazon.co.uk/AIMOS-S...

 

 

 

Look towards teh bottom of the page....1920x1080

 

 

JIm

 

awneil wrote:

jgmdesign wrote:
return them if they don't work

but if they only say they'll work to 1920x1080, I can't really complain that they "don't work" at  2560 x 1080

 

Or am I just being too honest ... ?

 

YEs, you are. wink

 

Sometimes the way I see it....Amazon created their policy, and they are more than profitable by that policy.  I am adhering to the policy.  It DID NOT WORK IN MY APPLICATION.  They dont ask questions, I dont add to the answers.

 

JIm

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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jgmdesign wrote:
towards teh bottom of the page....1920x1080

further down, they say 2560x1440

 

so we shall see - no worries about sending back in this case laugh

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
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Wow.  then you might have a solution you were looking for.

 

Jim

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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we shall see tomorrow ...

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
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The unit arrived, and works fine as far as the big display goes.

 

But as a KVM, it's rubbish!

 

The normal expected behaviour of a KVM is to allow the "console" (KB, Mouse, & monitor) to be switched between the 2 computers without the computers noticing.

 

But this thing behaves as if the KB, Mouse, & monitor have all been unplugged from one computer, and then plugged in to the other.

 

This is useless when using extended desktop - as I do - because everything from the external monitor gets dumped onto the main monitor when the external is unplugged!

 

angry

 

I might keep it just for switching the KB & mouse, but use the monitor input selection for switching the screen ...

 

frown

 

EDIT

 

Nice touch: it has a remote button, with lights to show if PC 1 or PC 2 is currently selected

 

Stupid feature: the PC 1/2 lights on the remote button are the opposite way around to the PC 1/2 lights on the main box! frown

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
Last Edited: Wed. Sep 23, 2020 - 04:12 PM
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awneil wrote:
The normal expected behaviour of a KVM is to allow the "console" (KB, Mouse, & monitor) to be switched between the 2 computers without the computers noticing

Well, that's the way all the previous KVMs I've had - 3 different makes & models - have always worked. But they've all been PS/2 + VGA

 

awneil wrote:
this thing behaves as if the KB, Mouse, & monitor have all been unplugged from one computer, and then plugged in to the other

Seems to be common with USB + HDMI switches these days.

 

I guess this is what they call, "progress" ?

 

frown

 

But I found the following after a chat with a very helpful tech support guy at Startech:

 

  1. To have the USB devices appear to remain permanently connected, you need a switch with "DDM" (Dynamic Device Mapping) ;
  2. To have the HDMI device appear to remain permanently connected, you need an EDID emulator (actually, one per PC)
    eg, https://www.startech.com/en-us/a...

 

Most EDID emulators seem to be two (or more) times the price of the KVM - so I think I'll just stick with switching sources on my monitor!

 

EDIT

 

Or maybe the EDID stuff can be done on a microcontroller: https://www.st.com/resource/en/a... ...

 

 

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
Last Edited: Wed. Sep 30, 2020 - 05:08 PM
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awneil wrote:
Seems to be common with USB + HDMI switches these days.

Been trying to get the old KVM to work with one old computer (VGA) and one new computer (HDMI), so this topic has been informative.

I'll try the video source switch as the monitor has both inputs, but did not know I could use both at the same time (by switching sources). Thanks.

 

Jim

 

 

 

(Possum Lodge oath) Quando omni flunkus, moritati.

"I thought growing old would take longer"

 

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My HDMI monitor has two HDMI inputs; not sure if it'll work the same on a monitor with one VGA and one HDMI input - but you'll soon find out!

 

 

HDMI-to-VGA converters are available (I used them on my first RPi; before I got an HDMI monitor) - so you should be able to adapt the HDMI computer to VGA to work with the old switch ...

 

 

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
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And EDID is based on ... I2C :) Presumably the graphics card is the master, and it interrogates the monitor/slave.