Capturing DOS video output?

What would be the best way to capture video output from an old computer running DOS games and programs? Is there some sort of external scaler that will convert the video output from an old dos computer into something more usable like 640x480? I've done some research on this, and for some reason I can't seem to find any useful info.

Also, i know i could just use DOSBox, but i'd much rather use a real computer.

I should also say that i've found a number of vga to tv converters, but i can't seem to find out if they will accept resolutions other than more common ones like 640x480 or 800x600. A lot of dos games use other lower resolutions that wouldnt work with a lot of these things.

 

I use one of those VGA to TV adapter.
http://www.ebay.ca/itm/PC-VGA-to-AV...=US_Video_Cables_Adapters&hash=item460e8933e5

Then you just record with any other capture device with S-video or composite. You will not be able to capture in high resolution since its an analog TV signal but for those old low res games it is perfect. I mostly use it to play DOS games on my CRT TV but i know you can record it no problem.

 

you could try one of them ega/cga to vga conveters / scallers they're cheap enough on ebay from china

 

are you talking about the gbs-2200? i was thinking about it. has anyone actually tried using one of those in this way?

 

i habe an 8220 yeah but not tried it with a dos output but if its CGA/EGA then it should work seen people use them for older computers, maybe check youtube for anyone using them on a dos system

 

If you use the GBS, you still need a way to record the VGA output from it though

 

How is DOSBox not using a real computer? What the hell are you running DOSBox on, your fridge?!

You'll probably get a better video out of DOSBox.

Here's a recording with a capture card:

http://www.youtube.com/watch?v=Ao6IgHh4wqI



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Here's a recording of Monkey Island with DOSBox:

http://www.youtube.com/watch?v=5ejqKK-B53s



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I don't think it's about video quality, more than accuracy. Emulated systems and their games look better on modern computers as all the colors and pixels are displayed in great detail, but lots of people swear by adding scanlines and other stuff to imitate the look of the crappy 20 year old tv.

 

If you capture direct from the machine - there will be no scanlines.

Scanlines were a product of being viewed on a CRT device.

 

What crappy 20 year old TV?! PCs never used TVs or crappy RF/s-video, they used decent monitors with RGB signal. We're talking about emulating DOS, not an entire machine.

 

Its Using an emulated computer on real computer

I also prefer to use "the real deal", Not only for the nostalgic aspect but because I love to play around with old hardware.
Also, I Collect Vintage sound cards and the Emulated FM music in Dosbox is not on par with a good quality OPL based Card.

There are also some hardware tricks that can be done specifically with a "real" Dos PC and maybe that someone wants to record that.

 

indeed, there's also emulation speed can be hard to nail the best settings with dosbox to get an authentic speed / emulation

 

Do you know if the hd15 out port on that thing outputs the same scaled output as the composite and s-video ports, only in RGB? Or is it just a pass through?

 

x

 

No it isn't. DOS isn't a computer, it's an operating system. It's an emulation of software, on an Intel-based machine that would most likely be capable of running the original software. Sure, there's an added element of having to emulate some hardware-based chips for such things as sound, but for the purpose of capturing video, DOSbox would give a decent result as most games don't HAVE to use that particular sound card / graphics mode / whatever it is

I totally agree that original hardware is best for PLAYING the games, but for capturing, you're never going to get quite the same result using a crappy s-video capture card.

 

Sorry but i think you are mistaken. DosBox is not merely a DOS emulator but there is also a full PC emulator under it. In the case of Dosbox there are many advantages to having the system working as a full emulator. That Is also why it is so easily ported to all kind of other systems, they even ported it to Amiga.

You can read about it on the DosBox Wiki page, they explain how DosBox is a full emulator.
http://en.wikipedia.org/wiki/DOSBox

This being said, I agree that for most people, DosBox is indeed to most convenient solution to record DOS gameplay videos and it will also give you a better quality result to boot, but there are many reasons why you might want to record the actual real hardware.

For exemple I found a hardware way to limit frame rate in some games that traditionally are limited by the CPU. Those games are usually always too fast or too slow depending on how much stuff is going on on the screen. While some people might claim this is part of the authentic experience of the game it annoys me.
The solution i found rely on using a very slow video card in a very fast machine. As far as i know this is not reproducible in DOSbox.
Hence I actually want to record videos of it from a real machine. ( I havent goten around to doing it yet though )

 

There's not such thing as "authentic speed" It's a PC. Try to run Wing Commander 1 on a 486 - you'll get a few thousand frames per second and game will be unplayable.

And i played latest DOS games at very high resolution on my PC in 1997 not because of CPU but because it had insanely fast 2D video card with lots of VRAM (32Mb).
P.S. there are Ctrl-F11/F12 keys in DOSBox so you can run those 8086 era games that will go crazy even on 386 or set cycles to 500000 and run some 1995 FPS game with 1600x1200+ resolution and 100fps. And yeah, i got CRT display and damn good one, probably the best of those that can run with normal video cards ( 23" 2048x1536@120 native resolution).

DOSBox isn't perfect though - both dynarec and interpreter CPU emulation cores still have some issues and yeah there's no perfect FM sound emulation. Very close to real thing but not the same.

 

It is just a pass through, usually to connect your monitor. I have observed no degradation of signal or delay while using this gadget. It feels just as good as the vga output of your video card.


Edit: This being said, VGA is basically RGB but with higher sync frequency than the TV RGB. If you can find a VGA capture device you could capture from the VGA port in high quality RGB and then you could use the S-video to monitor. Its actually pretty fun to play low res Dos games on a TV. This is actually what I mostly use this gadget for.

 

Ok so I have a gba-8220 that I didn't get for this purpose, but it would be cool if it could be used. I think it might be defective, though. I have my computer hooked up to it via VGA and the only screen resolution it will accept is 640x480. I have the output connected to an old CRT monitor that will definitely accept just about any resolution I throw at it. Using the gbs, DOS text mode doesn't show, low res games (<640x480) don't show, and the only screen modes in qbasic that work are 11 and 12 (640x480). Anything higher than 640x480 won't show, either. Is this normal, or does it seem my unit is defective. Also, if I hook up a component source, everything looks pink, even with just the green (Y) plugged in. Can anyone who has one of these things tell me if they can use it to scale a pc source that is anything other than 640x480?

 

it should accept resolutions below 64x480 but as far as i'm aware not above that. the 8220 can scale up to 1024x768 or 13**xsomething (cant remember)

if using component it shouldnt be pink, you can manually adjust the pots for Red Green and blue individually they should be just infront of the VGA input port.
i don't have an older dos system to test it myself but it should support CGA and EGA resolutions.

you can also make a simple circuit which turns VGA > Composite or buy an adapter cable but the quality will suffer.