Making a laptop take VGA input, or a cheap, tiny display.

June 14, 2007 6:28 PM

Making a laptop take VGA input, or finding a cheap, tiny display.

I have a computer which I always connect to remotely. However, once in a blue moon, I need to physically hook up a monitor to it, usually for troubleshooting purposes. I am tired of disconnecting my primary monitor and hauling it to this 'server' whenever it refuses to boot due to something stupid.

So what I'm looking for is either:
A. A (hopefully USB) device that will allow me to turn a laptop into a monitor. Something like a USB video capture card which accepts VGA would be optimal. My laptop is a Macbook, so no PCMCIA slots.

B. A tiny (as in, several inches big) LCD monitor that I could keep next to the computer at all times.

Now cheap is the name of the game here -- I'd prefer to spend as little as possible on this, since quality isn't really important. If I can't find anything decent, I'll have to breakdown and get a KVM switch, which I'd like to avoid due to the need to run cables (my monitor isn't really close to this 'server'). I'm sure that people who run lots of servers must have easy ways of connecting a monitor to an arbitrary one. What should I do?

posted by bsdfish to computers & internet (14 comments total)

Interesting question. I'm afraid I don't have an answer for you but maybe some other ideas...

Judging by your username I assume that the box is a headless Linux/Unix box? If you don't need the GUI that X provides maybe you'd have some luck setting up a serial console on the machine and getting a null modem usb adaptor for your Macbook.

There is plenty of instructions on the web about setting up serial consoles and on my headless boxes it provides a very convenient when the networking has carked it.
posted by puddpunk at 7:30 PM on June 14, 2007

"...it provides a very convenient backdoor when the networking..."
posted by puddpunk at 7:31 PM on June 14, 2007

Good luck finding a USB VGA Capture card, I've never seen such a device, in fact PCI VGA Capture cards are hard to come by as well (and in my experience are not very cheap either).

How much space around this server do you have? The easiest (and cheapest) solution would be to find an old CRT or a cheap used LCD (hard to find anything smaller than 15") to keep by it.

Another option would be to get a VGA to Composite adapter that will allow you to get an easily available USB Composite Video Capture adapter to read in the video. This is not the most optimal solution, but it should solve your problem.
posted by stew560 at 7:32 PM on June 14, 2007

Serial console is the way to go (for *nix).
If you have a serial port, you'e golden.
Google for linux serial console or bsd serial console; the first hit is the one you want. You can even get serial when grub loads (gogle: grub serial console)
posted by Cat Pie Hurts at 7:40 PM on June 14, 2007

Missed the macbook part.
You'll need a serial< ->usb adapter.

For reading the console, you'll want ZTerm or Minicom.
posted by Cat Pie Hurts at 7:43 PM on June 14, 2007

Totally missed puddpunk's answer.....what puddpunk said :)
posted by Cat Pie Hurts at 7:44 PM on June 14, 2007

You want a VGA 2 USB adapter. I use the Epiphan KVM unit (site is http://www.epiphan.com/ ).

This captures a VGA signal and spits it out to a connected USB computer- I use it as an emergency crash cart when I need to bring a dead server online in the datacenter.

I don't know if they have Mac drivers, but the hardware works OK- it's a little wavey, and a little laggy, but works well at low resolutions. I wouldn't use it for day to day use, though- it's fine for an emergency, but not much more than that. It's quite small- maybe 6 inches by 4 by 2.


Good luck!
posted by jenkinsEar at 7:47 PM on June 14, 2007

Cool, they have mac drivers:

http://www.epiphan.com/products/product.php?ppid=23

Linux, too. The main product page is at:

http://www.epiphan.com/products/product.php?pid=27
posted by jenkinsEar at 7:56 PM on June 14, 2007

You guys are right -- it's a headless Linux box that I usually VNC (or ssh) into. The problem is that once in a blue moon, the power goes out, and the box doesn't always come up, or I need to upgade some hardware and it gets errors, etc etc. Serial cable is actually a decent idea -- I didn't really think about that -- but doesn't solve the upgrade-hardware-not-detected problem.

I'm just really annoyed there isn't anyone hooking up small PDA displays to VGA cables and selling them for $30, and that no laptop I've seen has a decent video in. I guess there's always the option of getting a TV capture card and using a video card w/ TV out on that box (I think the existing one might have s-video) ...

Does anyobody know how the large server farms handle the once-in-a-blue-moon monitor needs?
posted by bsdfish at 10:10 PM on June 14, 2007

My cheap portable DVD player (Advueu PD710) has composite in - you could use that with the TV out video card.
posted by rfs at 10:32 PM on June 14, 2007

I dimly recall Radio Shack, or whatever they call themselves these days here in Canada, having a small (6" or so) LCD TV that had a generous assortment of inputs, not able to find it on the web now, thought.
posted by jjb at 11:03 PM on June 14, 2007

bsdfish: Most data centers have a mouse/keyboard/screen combo on little carts that just go where they are needed...

The systems I work on, which consist of many components, have a very large and elaborate KVM system with backup serial connections. Also a central unit to access all the components which is basically an intergrated mouse/keyboard/video that slides in and out of the rack and opens like a laptop
posted by puddpunk at 11:26 PM on June 14, 2007

Maybe you could use VNC?
posted by pantsrobot at 12:02 AM on June 15, 2007

What about an in-car LCD VGA display? Or even a tiny handheld TV that has a composite in? S-video can be combined into composite with a resistor and a capacitor, I seem to recall.

I imagine you can find some cheap handheld TV sort of thingy somewhere.
posted by 5MeoCMP at 6:14 AM on June 18, 2007