Play Mod'd 2600 on Computer monitor

[Kenwood]

I have a Mod'd 2600 (composite). What do I need in order to play my Atari on my computer monitor?

[jsoper]

http://www.viewsonic.com/products/tventert...ssors/vb50hrtv/

[Kenwood]

Are there any cards that will fit in a slot in my computer?

[tearex]

Any decent graphics card that has a video-in should work. Also any TV tuner card that has a video-in (in addition to the RF in).

[mos6507]

There is a potential problem here.

 

I bought one of those VEG LITE things that scan converts from NTSC to VGA and it just drops to a blank screen whenever it isn't given solid sync.

 

So things like the Supercharger load screen, Video Chess thinking, etc... don't display anything and that's really annoying. It can not be used for game development purposes because you want to see as much output as possible when your game is glitching.

 

Does anyone know of any LCD or VGA solutions that are tolerant enough to show you the same kind of picture you would get with a traditional TV including the "screwed up but visible" kind that the 2600 sometimes outputs?

[+batari]

There is a potential problem here.

 

I bought one of those VEG LITE things that scan converts from NTSC to VGA and it just drops to a blank screen whenever it isn't given solid sync.

 

So things like the Supercharger load screen, Video Chess thinking, etc... don't display anything and that's really annoying.  It can not be used for game development purposes because you want to see as much output as possible when your game is glitching.

 

Does anyone know of any LCD or VGA solutions that are tolerant enough to show you the same kind of picture you would get with a traditional TV including the "screwed up but visible" kind that the 2600 sometimes outputs?

932446[/snapback]

I think the problem is that wayward sync signals can actually break some monitors, and those monitors with protections built in will blank themselves when bad sync is fed to them.

 

Another problem could be that high-end scan converters are doing a full frame buffer instead of just a scanline or two at a time. With no VSYNC, there's no frame.

 

If you want a way around this, "tolerance" is probably not the right word, since those scan converters that may be "tolerant" are really just cheap. That is, too cheap to include any sort of protection circuitry and they only buffer a couple of scanlines, and simply double the input horizontal frequency, which is a little off of VGA spec.

 

So go for the cheapest, oldest piece-of-crap scan converter you can get your hands on, along with the oldest VGA monitor you can find.

[supercat]

I think the problem is that wayward sync signals can actually break some monitors, and those monitors with protections built in will blank themselves when bad sync is fed to them.

932472[/snapback]

 

Although multi-scanning monitors will blank themselves when out-of-range sync signals are fed into them, the auto-scanning behavior relied upon by the Supercharger loader and other such things is actually a consequence of protection designs of fixed-frequency monitors.

 

Basically, a monitor's sync circuits are oscillators whose natural free-running frequency is slightly below the proper video sync frequency. They include a circuit, however, to impart a small "nudge" when a sync signal is received. If the electron beam is almost all the way to the right/bottom of the screen, a horizontal/vertical sync pulse will trigger the retrace slightly before when it otherwise would have happened. Otherwise, the horizontal/vertical sync pulse will be ignored.

 

Modern monitors often blank in the absense of decent sync pulses not so much as a protection device (they could free-run rasters perfectly harmlessly), but rather because there's usually little point in wasting electricity powering a monitor for what 'obviously' isn't going to be a viewable display. In the case of the Supercharger load screen, it would be viewable, but there's no way for the monitor to know that.

 

LCD monitors and capture cards could perfectly happily self-sync, but as with monitors there's not usually any point to doing so. If sync pulses aren't being reliably received, it will usually be visually better to drop frames than to self-sync (which will produce out-of-alignment frames). Again, the monitor/capture card has no way of knowing that the display is actually showing something useful.