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Digitizing VGA? (take 2)
urgent asks: "In March of 2002, Ask Slashdot ran this article, wherein advice on 'hardware to digitize the VGA output of a PC' was sought. Most of the responses seemed to assume that remote administration of PC's/servers was the end goal. If you've got control of the software and/or hardware, it's pretty clear there are easier solutions for that. On the other had, there are many legacy and embedded systems where it would be nice to monitor and record display output. For instance, integrating old computerized factory equipment into a SCADA system, or recording old embedded maritime and medical displays (hint: jobs). My dream hardware would be a dongle that connected to a VGA out and could be polled over ethernet or CAN."
There's a plenty of VGA to IP boxes out there:
Heres one: It's bacially a 8-port KVM stwith with a built in computer thar does VNC. infor
Moneyed corporations, non-working 'poor' and criminal prisoners are turning productive citizens into tax-slaves.
So if such hardware exists (and it could certainly be made), this is yet another obstacle to a "secure" PC. Do other standards for connecting displays have Macrovision-style restrictions? Would Palladium hardware obselete all those monitors?
These are good for extending the output of the devices, but in the end, all you end up is the same monitor connected to a really long cable.
Remember... CAT5 DOES NOT IMPLY TCP/IP. I cannot emphasize this enough. If you plug one of these extenders into a switch, you will probably destroy both the switch and extender. They use cat5 simply because it is cheap and universally availible.
-- If you try to fail and succeed, which have you done? - Uli's moose
LCD monitors do this. There are KVMs that do this. Don't forget that two of those signals are simply trigers and not data that must be captured. The other two break very nicley into 3 8 bit streams. They run at about 300Kbytes per frame or 18000Kbytes per second at VGA uncompressed 60hz. Using a microcontroler this data can be piped directly into an mpeg encoder chip like the one Tivo uses form IBM which could compress that down to a manageable size with little effort. The stream should be able to be distributed with relative ease using a microcontroler with a built in ethernet controler like the tini from dallas. The end result would be a very small device that was relativly inexpensive that did the job he was looking for while being very dongle like. It would also have the ability to distribute it via a controler area network if need be.