I have been contemplating a solution for this for a while now and the last few months I have been acquiring a lot of Extron equipment....such as....http://www.extron.com/product/product.aspx?id=rgb202xi

The early RGB series of video converters and processors like the 202xi accept 9 pin Analog and TTL RGB inputs and output to VGA via BNC connectors usually. I picked up one of these and a bunch of other video processor units to convert CGA and EGA and hopefully other formats to various VGA, RGB and Component video formats.

The drawback is, is that you will need to make or get the proper cables. I have bought a bunch of cables recently to go with my Extron units, but I have not had time to try anything out except for converting my Intellivision RF output to SVIDEO and Component (without modding or hacking my intellivision)....I just used Extron products and a VCR to convert the RF to RCA Composite, then a couple different Extron video scan converters/decoders to upscale the composite signal to component and svideo (to my 40"Sony LCD TV)...I know it sounds like a lot of signal processing, but it looked amazing compared to the crappy RF signal on a modern LCD TV. It was just one of many projects I have planned.

Next thing I want to try is converting the RGB out on my Amiga 2000HD and my Tandy Color Computer 3 to my LCD VGA.

Extron units are readily available on eBay and much cheaper than some of the solutions out there....I am surprised more people are not snatching them up....they are very useful for retro gaming and extremely high quality (mostly made in the USA).

When I do some more testing I hope to create a thread with my findings and results.

I have to say I don't really see the point of these for retrogaming - as you pointed out they are made for industrial applications. So I suppose "perfect reproduction of vintage graphics" weren't really a concern when they designed these - as long as it allows whatever old machine to output a text to the screen, it fulfils its mission.

So if you have an old machine with a CGA or MDA card, I don't see any other option than sourcing an older 9-pin CRT screen if you are after the vintage graphics look. If you can't, it think it makes much more sense to replace your old card by a VGA card and connect it to any 15-pin VGA LCD.

carlostex wrote:

Monochrome TTL to VGA Adapter Box[/url], this would be even more useful. Costs 435USD.

What we would need is a retro project of this kind, it would be probably easier to just create one of these converter boxes to use with a VGA monitor.

This would be easier and much cheaper...http://www.ebay.com/itm/181648667477 (as mentioned above)...this seller even has multiple quantity!!....if I didn't already spend a lot on retrogear these last 3 months I would have bought two more of these just to have spares.

retrofanatic wrote:

carlostex wrote:

Monochrome TTL to VGA Adapter Box[/url], this would be even more useful. Costs 435USD.

What we would need is a retro project of this kind, it would be probably easier to just create one of these converter boxes to use with a VGA monitor.

This would be easier and much cheaper...http://www.ebay.com/itm/181648667477 (as mentioned above)...this seller even has multiple quantity!!....if I didn't already spend a lot on retrogear these last 3 months I would have bought two more of these just to have spares.

Thanks cool info. I suppose one would need to build proper cables right?

carlostex wrote:

retrofanatic wrote:

carlostex wrote:

Monochrome TTL to VGA Adapter Box[/url], this would be even more useful. Costs 435USD.

What we would need is a retro project of this kind, it would be probably easier to just create one of these converter boxes to use with a VGA monitor.

This would be easier and much cheaper...http://www.ebay.com/itm/181648667477 (as mentioned above)...this seller even has multiple quantity!!....if I didn't already spend a lot on retrogear these last 3 months I would have bought two more of these just to have spares.

Thanks cool info. I suppose one would need to build proper cables right?

I am still researching this. But I don't think so in most cases.

*EDIT - I think for the most part a standard 9pin to 9pin cable for the input will work, but sometimes RGB pinouts on different systems are not the same (I can post pinout diagrams). Also, for the output, you would typically need a 5 wire BNC to 15 pin VGA connector cable. I have seen these go for about $12 from china and just purchased one recently for about that amount.

It is kind of a hidden gem in the retrogaming world I have found out lately. There are a few examples I have read briefly in a blog somewhere, where a couple of people have successfully used an Extron 202xi to connect their Amiga to a standard VGA LCD monitor with very good results....Like I said I have one of these units and just have not had the time to test. I have pinout diagrams and from what I have read so far, the cables are not actually that special in some cases. It's just a matter of plugging the 9 pin monitor cable into the proper 9 pin input on the Extron (ANALOG OR TTL) and then having a proper BNC to VGA cable to connect your LCD VGA monitor on the output. That's the beauty of this older Extron model - it has both Analog and TTL inputs.

I am planning on trying mine with my Tandy 1000's as well.

Like I said I just have not had the time to test it out, but it looks promising.

Ok so it's just the BNC to VGA cable that is needed.

carlostex wrote:

Ok so it's just the BNC to VGA cable that is needed.

Yes (sorry, just edited my post above to say that), from what I have gathered from my research so far. Sometimes the cable is called an RGBHV to VGA cable as well.

Download the manual from here for the 202xi model to take a look at the connections....it's not so complicated once you familiarize yourself with it a bit...http://media.extron.com/download/files/userma … B202xi_revE.pdf

From what it looks like in the manual, you will need a special cable to connect the unit to your computer, but I am convinced that that is not the case from some of the blogs I have been reading and from my research on the pinouts (which is found in the manual as well).

I will try and test soon and try to have concrete evidence of if it works well or not.

Maybe there are other Vogon members with much more experience and knowledge about this subject than me (in regards to using these Extron units)...if so, I hope to hear their experience with it.

Here is an excerpt from the manual for this RGB Extron unit...I don't know if anyone is interested in this topic, but I will post anyways just in case someone finds it useful down the road.

Even though the manual says "this is for use with Extron MBC cables only", I think any 9 pin cable with proper pinout as per the diagram above will work in most cases with older CGA, EGA, and other Analog RGB signal computers (15kHz-up) such as Amiga and Tandy computers, as long as you plug in to one of the proper ports in the above diagram.

I know my Tandy outputs out the standard Analog TTL RGB as in "Input #1" in the image above, so theoretically it should work to connect it to the Extron unit with a regular 9 pin monitor cable to convert the analog 15kHz signal to standard VGA. Again, I will post my results when I have time to test it out.

I intend to eventually test this Extron 202xi unit with the RGB output of my Sega Genesis, Sega Master System, Tandy 1000 (various models), Amiga systems, Commodore 64, Atari ST, etc.

I have already got the DIN connectors from eBay (like the ones pictured below) to build my own cables as necessary for some of these systems.

It may be as simple as connecting R G B and Horizontal and Vertical sync to the proper inputs of the 9 pin connector in the diagram above (I hope), but I suspect it may not be so straightforward with all systems.

*EDIT- ....and FYI, this is the BNC connector (RGBHV) to 15 pin VGA cable to use for the output from the Extron unit to a regular 15 pin VGA monitor...(just bought it off eBay today)...

I have a 202xi too and like you I haven't had a chance to try it 😒

My intended application is CGA. However I was under the impression that the 202xi only outputs 15KHz Analogue RGB... i.e. TV frequency. I was going to hook it up to a TV via SCART socket. If you want to connect it to standard VGA you'd need a scan doubler of some kind.

Find a MultiSync CRT: those work fine as well.

bjt wrote:

I have a 202xi too and like you I haven't had a chance to try it 😒

My intended application is CGA. However I was under the impression that the 202xi only outputs 15KHz Analogue RGB... i.e. TV frequency. I was going to hook it up to a TV via SCART socket. If you want to connect it to standard VGA you'd need a scan doubler of some kind.

Great to hear someone else has one of these and is trying to use it too.

I think you're right about outputting to 15kHz only.

I spent a few hours last night trying to display a picture on my LCD and CRT VGA monitors from my Amiga 2000HD and Tandy 1000 TL by using the Extron RGB 202xi, and I failed miserably 😢 😵 .

The best I could do was get a super blurry picture on my LCD if I ran the output from the RGB 202xi to a seperate Extron VSC500 digital upscaler and then output to component going to my LCD. I guess my VSC500 can upscale to ~30kHz and the RGB 202xi cannot.

Every time I connected the RGB 202xi to my VGA monitors they both said "signal out of range".

I have a few other ideas of how I can get everything to work, but it may take more cables, more time, and more $.

Just saw this interesting video. Maybe in the future there will be enough interest to drive a market for retro computing, that will allow such products to become affordable.

carlostex wrote:

Monochrome TTL to VGA Adapter Box, this would be even more useful. Costs 435USD.

What we would need is a retro project of this kind, it would be probably easier to just create one of these converter boxes to use with a VGA monitor.

Couldn't this be done super super cheaply and reasonably accurately with a fast microcontroller, CPLD or FPGA?

Using something like the Parallax Propellor, Hsync and Vsync into external interrupts, lookup table to change the RGBI values to analogue values... I think it could be done for under $80.

Is there any chance that this will work for our intended purpose (displaying EGA/CGA/MDA output of an old computer on a modern LCD)? :

http://www.ebay.com/itm/321680159023?_trksid= … K%3AMEBIDX%3AIT

Despite the description, the GBS converters don't handle TTL-level signals as used by true CGA & EGA.
They do however support analogue video with the CGA & EGA horizontal scan rates (15/24Khz).
I wasn't able to get my GBS-8200 to sync to the signal from my homemade CGA->Analogue RGB converter, but I'm planning to try it again with the output from the Extron 202xi. It seems the GBS units are quite picky about how the incoming sync signal is formed.

tayyare wrote:

Is there any chance that this will work for our intended purpose (displaying EGA/CGA/MDA output of an old computer on a modern LCD)? :
http://www.ebay.com/itm/321680159023?_trksid= … K%3AMEBIDX%3AIT

No, the GBS-82xx converters only take analog signals (the ebay descriptions are misleading, CGA, EGA, etc... refer to the supported input frequencies).
If you want to use that converter with a real CGA/EGA card, you would have to to build an additional D/A converter, like this guy has done.

From my understanding these PCBs are meant for arcade games: not computers.

SquallStrife wrote:

carlostex wrote:

Monochrome TTL to VGA Adapter Box, this would be even more useful. Costs 435USD.

What we would need is a retro project of this kind, it would be probably easier to just create one of these converter boxes to use with a VGA monitor.

Couldn't this be done super super cheaply and reasonably accurately with a fast microcontroller, CPLD or FPGA?

Using something like the Parallax Propellor, Hsync and Vsync into external interrupts, lookup table to change the RGBI values to analogue values... I think it could be done for under $80.

Sorry for the bump, but I actually found something like this.
https://sites.google.com/site/tandycocoloco/rgb2vga

I was looking at Tandy 1000's on eBay and was like "yeah, but finding a RGB CRT is going to be a pain", building something like this isn't out of the question (might cost around 130$, 80$ of it being the FPGA board), but it's not going to be 100% accurate either, just accurate enough for the kinds of purposes people here might prefer. Keeping in mind that "VGA" is also on the way out and most LCD monitors are dropping it to save part costs.

More or less, every time I look at vintage (pre-286) computers on eBay I'm like:
Monitor - Nope
Keyboard - Nope
Floppy disks - Nope

^Doesn't seem to relevant for the IBM PC scene. I look forward to the day we can have a small and affordable CGA/EGA to VGA box converter with good image quality.