Jrok board with vga monitor

racer2e

Member
Joined
Dec 17, 2007
Messages
269
Reaction score
14
Location
Donald, Oregon
Since the Jrok board does not have a vga connector, did you guys just cut the end off your monitor cable or did you solder a vga connector on your jamma harness? How do I wire in the vga monitor? Does anyone have a pinout showing what Jamma wires go to what pins on a 15 pin vga connector? I assume I need to use the posative and negative sync?
Thanks, Jayme
 
Since the Jrok board does not have a vga connector, did you guys just cut the end off your monitor cable or did you solder a vga connector on your jamma harness? How do I wire in the vga monitor? Does anyone have a pinout showing what Jamma wires go to what pins on a 15 pin vga connector? I assume I need to use the posative and negative sync?

VGA connector pinout
http://en.wikipedia.org/wiki/VGA_connector

From my testing and feedback a 'lot' of VGA monitors will work fine with just the JAMMA Red/Green/Blue and composite sync being fed into the Horizontal sync input.
Also tie video-ground to GND on the VGA connector.

If composite sync into h-sync doesn't work then use the 2 pin sync header on the board with the connector and feed orange into h-sync and yellow into v-sync.

- James
 
I was hoping to salvage the Stargate monitor that was in my cabinet, but after a cap kit and every adjustment I know of, I still have a wonky monitor. Does anyone have a step by step on setting up the JROK board with a VGA monitor? Pics would be great. I think I understand JROK's explanation above but I'd like to be sure.
 
This might make is a bit easier.

Wiring for the standard 15 pin VGA socket, so you could use a standard VGA cable to hook to a monitor. I got to try a couple more monitors recently and all could handle just a composite sync output from the board on the VGA h-sync input.

Front
vga_d_front.jpg


Back view - top side ( color input )
vga_d_back_top.jpg


Back view - bottom side ( sync input )
vga_d_back_bot.jpg


- James
 
yes but how does it look?

I'm curious on how well it looks in comparison to the original medium resolution monitor.

I have a completely rusted out Defender with missing boards that I've shelled out. The monitor looks to be not worth the effort to get running because of the level of corrosion and rat crap in there. SERIOUSLY.

I'm going to look to see how well the JROK board looks on a VGA Monitor, Does anyone have any feedback on this?
 
i hooked-up my 60-in-1 to a vga and didn't like it. way too crisp pixels. i didn't have the same feel as a cga.

I'm curious on how well it looks in comparison to the original medium resolution monitor.

I have a completely rusted out Defender with missing boards that I've shelled out. The monitor looks to be not worth the effort to get running because of the level of corrosion and rat crap in there. SERIOUSLY.

I'm going to look to see how well the JROK board looks on a VGA Monitor, Does anyone have any feedback on this?
 
I agree that it looks better in standard res, but I can live with VGA. I got tired of working on a g07 that was giving me trouble and had a 19" vga so I hooked it up to my jrok board in my defender and it's good enough for me. if you can live with it, 19" vga monitors are dirt cheap.

i hooked-up my 60-in-1 to a vga and didn't like it. way too crisp pixels. i didn't have the same feel as a cga.
 
I'm curious on how well it looks in comparison to the original medium resolution monitor.

The original monitor was only Standard resolution.

I'm going to look to see how well the JROK board looks on a VGA Monitor, Does anyone have any feedback on this?

Well.. the thing you'll probably see is it look more pixelated. You tend to get a much sharper picture than with standard rez. so the pixels sort-of 'pop-out' at you. It depends on just how good a VGA monitor it is too. This is an effect which is a LOT more pronounced on a LCD.

Also.. as the vertical resolution is twice that of standard res, you get a 'fill-in' effect between the lines making the picture look a lot more solid.

- James
 
I have a WG D9500 to use with my sysfpga board. Is there any difference between using the PCBA connector versus your VGA cable wiring here? If using the VGA cable would I leave the board in non-VGA mode since the monitor can do the original resolution?

Thanks!
Gary
 
For the Dell monitor I was using I needed the male plug instead of the female, which I soldered directly into the wiring on the Jamma Harness.
This is the layout that allowed the JROK to play directly on the monitor without a CGA/VGA converter card-

Red wire to pin 1 (to Jamma Red)
Orange wire to pin 2 (to Jamma Green)
Green wire to pin 3 (to Jamma Blue)
White wire to pin 6 (to Jamma Video GND)
Yellow wire to pin 13 (to Jamma Video Sync)

IMG_20120921_100253_zpsed603c04.jpg
 
Last edited:
The original monitor was only Standard resolution.



Well.. the thing you'll probably see is it look more pixelated. You tend to get a much sharper picture than with standard rez. so the pixels sort-of 'pop-out' at you. It depends on just how good a VGA monitor it is too. This is an effect which is a LOT more pronounced on a LCD.

Also.. as the vertical resolution is twice that of standard res, you get a 'fill-in' effect between the lines making the picture look a lot more solid.

- James

For this there is a really good solution called the SLG-3000:

http://wp1114205.wp150.webpack.host...anguage=en&&XTCsid=dhru28203rq897592k89kqa006

which will make it look a LOT like the real thing on a VGA monitor.

It simply blanks every odd ( or even) scanline. Maybe this could even be done (by software ? ) directly on your board James ?
 
It simply blanks every odd ( or even) scanline. Maybe this could even be done (by software ? ) directly on your board James ?

That might look ok on a tube, but on an LCD it looks horrendous, I just modified the FPGA code to test blanking the even lines. It actually looks like there's something wrong with the board :)

- James
 
That might look ok on a tube, but on an LCD it looks horrendous, I just modified the FPGA code to test blanking the even lines. It actually looks like there's something wrong with the board :)

- James

Maybe include it as a setting for VGA CRT users ?

Do you have a picture of how it looks on LCD ?

The SLG-3000 allows you to switch between odd and even scan lines, reports say some have better results with odd, others with even, worth retrying that too. Apart from that, there may be some fine tuning on the SLG-3000 that I am not aware of...
 
Last edited:
I think it's actually pretty weird that it looks so bad on a LCD with your board.

Here is an example how great it works on LCD:
http://m.youtube.com/watch?v=S3sb__XK0FQ

Because of the camera and youtube limitations (blocks) you don't get the entire experience, however you can clearly see what it does......
I've seen it in person on an LCD and it really makes it look much better and much more CRT like.

I'd love to see someone make a video with your board and a real SLG-3000 hooked up to a LCD.
 
Hey,

find here some links on youtube for the SLG3000

http://www.youtube.com/watch?v=S3sb__XK0FQ
http://www.youtube.com/watch?v=VOeC5PdbkBM

We developed the SLG3000 in the german ArcadeZentrum Forum to enhance picture quality on 31Khz, 640x480 (480i) on CRT and LCD. So this scanline thing works good with CGA/VGA scalers, 60-in-1 cards, consoles, scaler, line doubler and and and...

Some theory
http://scanlines.hazard-city.de/

This is a thread in SHMUPS Forum regarding scanlines with SLG3000, lots of pics and setups.

http://shmups.system11.org/viewtopic.php?f=6&t=33454

:)
 
Last edited:
I think that is exactly what the SLG-3000 would produce and it is a hell lot closer to what you see on a CGA CRT IMHO !

If I would have to run your board on a VGA monitor I would LOVE to have that option built into the menu !
 
I think that is exactly what the SLG-3000 would produce and it is a hell lot closer to what you see on a CGA CRT IMHO !

I think with the backlight on the LCD you lose a lot of contrast with the black lines, this is me just idly speculating, but with the CRT the black level on the undrawn scanlines is a lot darker than with lines on the LCD. I blame the backlight ! I'd predict that with something like an OLED display it would probably look pretty good, but seeing as the only OLED's I have are 2" is size it'd be a bit hard to see ;)

This could add this as a feature in a future version. I don't see the point of odd/even lines though, seeing as the line detail is identical for both odd/even lines when up-scaled to VGA. Except for the monitor duplicating lines in resizing the vertical resolution to fit the panel. To be honest I think hitting 'auto-adjust' on the monitor would have more of an impact if the monitor is doing the upscaling from say 480 odd lines to 800, or 1024, or suchlike.

- James
 
Back
Top Bottom