Composite to VGA adapter 1

[itsmoked]

I've spent 2 hours looking on the web for a composite to VGA adapter.
There are lots of them. I actually bought a nice one with a resolution button on it.
Unfortunately they all seem to only work with about 640x480 or higher composite signal.

I have a bunch of machine tools that have this same monitor and it's reaching end-of-life and I'd like to switch them to cheap LCD displays.

The existing monitor has these specs:

The issue seems to be the 384 x 304 resolution being pretty dang low. Additionally the monitors are all monochrome and it seems everyone selling adapters is thinking VGA => Color.

Any ideas out there?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[IRstuff]

Perhaps you drilling too far down. The generic frame grabber doesn't much worry about low input resolution. Maybe something like

https://www.amazon.com/Elgato-Video-Capture-analog-iPhone/dp/B0029U2YSA

?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[itsmoked]

Thanks IR. That is one way I was thinking of skinning-the-cat.

That one looks good but:

- Video resolution: 640×480 (4:3) or 640×360 (16:9).

makes me hesitate.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[IRstuff]

But, isn't that really on the other end, i.e., you'll be oversampling the composite video at ~2x to generate the VGA, but that shouldn't hurt anything.

Am I understanding that correctly? You've got something that outputs 384x304 that matches the existing monitor. So, you can digitize that same video at 640x480, and you'd wind up possibly with a letterbox display format and some aliasing on the horizontal. If you get a full-blown frame grabber, it could digitize at 384x304 and then upsample to get to VGA by interpolation.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

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[VEBill]

As hinted above, rather than referring to the specs for the obsolete monitor, refer to the spec for the video output signal itself. For example, 'RS-170 Monochrome' or whatever it is.

An old video standard (monochrome composite) probably would use 'Lines' of resolution instead of pixels.

Good luck.

 

[MacGyverS2000]

That's a pretty low res (called CIF+)... my old ZX Spectrum could run at that res (think I paid less than $100 for it, a thermal printer, memory pack, and various other bits). You may find some more info with those keywords and composite video thrown in for good measure.

If you just want a replacement monitor, try here:

http://www.omnivisionusa.com/monito...ement-crt-monitors/dynapath-mono-9-inch-.html

If you want to go LCD, you may find some useful info here:

http://www.practicalmachinist.com/v...converters-solve-dead-monitor-problem-119609/

Dan - Owner

http://www.Hi-TecDesigns.com

 

[itsmoked]

Thanks all. VE1; The RS-170 didn't help much in searching.

Thanks Dan, the CIF+ was a new one to me. Interesting! Seems there's several security oriented Digital Video Recorders that will accept CIF+ video streams and could probably be forced into 'monitoring' mode where they just pass the CIF+ onto the system display screen which would be a modern display of some sort. DVI or VGA.

I've already excavated that Practical Machinist thread. Thanks.

In messing with the monitor I'd proved to myself that the kine flyback supply was dead. Removing the high voltage CRT lead and setting it up with a tiny arc path, it put out nothing at all. I'd scoped the video out of the controller and it looked like classic Composite with the negative blanking pulses and everything. The composite was interesting since this display is strictly one bit there was no continuous variation just a comb-looking field where it was peaked for an ON pixel and zero for an OFF pixel, looking about like you'd expect for a screen covered with text.

So I knew the video was good.

In desperation I tore the single monitor control board out and in the process discovered a classic evaporated solder joint on a male soldered-in pin on the cable going to the flyback. I scraped the solder resist off the trace and scraped the lead shiny on the pin and hit it with good ol Rosin 44. Soldering the pin solidly to about 10 sq mm of trace instead the original minimum solder to just the edge of a corner of the trace.

I fed the monitor 12VDC. I didn't have that whacked-out CIF+ video source at my office but was happy to see amber raster. I took it back to the machine shop and installed it. It worked! It actually looked pretty dang sharp too. The guy was ecstatic and the crisis has receded for the moment.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[MacGyverS2000]

Good deal...

Dan - Owner

http://www.Hi-TecDesigns.com