Mike's PCjr Page

I've seen several threads on here talking about using a modern LCD monitor, some spoke of the Comrex (model CR-5400), and GGLABs unit.
Is there a prefered solution to getting the CGA to a modern LCD.

while I like the feel of the original Jr monitor for games, development is rough looking at the monitor for hours...

I guess I only know of this.


I have picked up a few Jrs and XTs but have no desire to ever go back to the crts I threw out back in the early 2000..

Either the gglabs unit or C128-DAC, must be used with a Gonbes 8200 or 8220. I have the C128-DAC. I Like it, but I have heard that the gglabs unit is better.

Found this.

https://www.ebay.com/itm/15Khz-CGA-RGB- ... 3316354604

Chuckphd53 wrote:Found this.

https://www.ebay.com/itm/15Khz-CGA-RGB- ... 3316354604

Looks like a really nice unit but I think KenG's suggestion is cheaper and that ebay one doesnt say anything about supporting RGBI.

I'm not a video expert so I may be wrong or confused.

Asked the Vendor about this unit, here is the response..

The converter is designed specially for the standard CGA type RGB signal. The RGB output from the source device must be either 15.62KHz(Hf) / 50Hz(Vf), OR, 15.73KHz(Hf) / 60Hz(Vf), so the converter can work properly.
If compatible, you may use our CGA DB9 to HD15 Pin VGA Adapter Cable to pass the RGBS signal feed into this converter for process. The DB9 pin-out connection on each end must match in order to pass the correct video signal properly. Please check the pin-out diagram.

Chuckphd53 wrote:Asked the Vendor about this unit, here is the response..

The converter is designed specially for the standard CGA type RGB signal. The RGB output from the source device must be either 15.62KHz(Hf) / 50Hz(Vf), OR, 15.73KHz(Hf) / 60Hz(Vf), so the converter can work properly.
If compatible, you may use our CGA DB9 to HD15 Pin VGA Adapter Cable to pass the RGBS signal feed into this converter for process. The DB9 pin-out connection on each end must match in order to pass the correct video signal properly. Please check the pin-out diagram.

Maybe I'm beating a dead horse but the issue is that the vast majority of these converters are for "analog CGA" which is just a bastardized way of referring to the common 15KHz signal produced by many vintage devices (arcade games, 16-bit home computers and game consoles, etc) where the color levels are analog. "Digital CGA" refers to the signal generated by the PC CGA card, PCjr, Commodore 128, and a handful of other devices. The refresh rates are still "CGA" but the color information is digital and uses an extra intensity signal. So you need a device to convert "digital CGA" to "analog CGA" then another to convert "analog CGA" to VGA. I'm not aware of a standalone device that does both conversions.

From my reading of the ad, you would still need either the C128-DAC or gglabs unit to work with this. I have no idea if this works better than the Gonbes units. The only advantage I can see is the nice case. I bought a case that houses my C128-DAC and Gonbes 8200 on eBay. I believe there is a different one available now. I would compare cost of C128-DAC or gglabs unit, Gonbes 8200, plus case to C128-DAC or gglabs unit plus this unit. That would still leave the DAC part uncased. If I were do9ng it again, I would try the gglabs plus Gonbes solution.

I have 2 PCjr monitors for my 4 PCjr units and had been interested in utilizing a VGA monitor when I saw this thread. But the cost to purchase a C128-DAC, Gonbes 8200 board and a nice 3D printed case was well over $100 ... and that made me reluctant to buy. So I put these items on my Christmas list and my brother-in-law bought me everything!

Those Gonbes units are not that great, they are rather noisy line doublers and require the CGA2RGB DAC. This is a superior solution : https://youtu.be/9SII7ujB3FY

The ideal solution for a modern LCD is the Open Source Scan Converter (OSSC) combined with the GCLabs CGA2RGB DAC.