Build Your Own Arcade Controls Forum
Main => Raspberry Pi & Dev Board => Topic started by: gizmo1990 on November 15, 2018, 12:28:19 pm
-
I'm slowly (very slowly!) putting together a cab and have an old WG monitor which I need to recap and get an isolation transformer for. Amongst the other hundred things I need to do, eventually connecting the monitor to test the picture is a priority.
With this in mind, what are the current methods for connecting a Raspberry Pi to a proper arcade monitor at 15khz? I've read about VGA to RGB Downscalers, the GBS 8100 and even the jpac years ago, but they all seemed to be hit and miss. Is there some all singing dancing pi addon which will achieve this feat? Perhaps it still doesn't exist? I thought I'd ask here for a definitive verdict.
Any advice much appreciated.
-
The Pi can output 15khz natively. You would need an HDMI to VGA adapter and then a VGA breakout cable and then pin up the end of the VGA cable with a .156 molex connector for your monitor. But the gert VGA666 adapter, which is a Pi hat adapter, is probably a better way to go if you don't need to use your GPIO pins. You would still need to do the VGA breakout cable with that as well.
-
You could use gert vga666 and possibly jpac.
-
Thanks for the replies guys. I'd not heard of the gert666 before, I'll pick one up!
Regarding the 15khz, is that outputted by the gert666? Also the VGA to molex cable, I thought molex connectors were strictly power related? Do they handle video signals too? I've looked around for wiring guides but I'm not seeing anything, am I missing something?
@keilmillerjr What would the jpac be adding in this instance?
-
Thanks for the replies guys. I'd not heard of the gert666 before, I'll pick one up!
Regarding the 15khz, is that outputted by the gert666? Also the VGA to molex cable, I thought molex connectors were strictly power related? Do they handle video signals too? I've looked around for wiring guides but I'm not seeing anything, am I missing something?
@keilmillerjr What would the jpac be adding in this instance?
Gert can do 15khz. You need to do some research as to how possibly posted on their github?
Molex is used everywhere from cars to CNC machines.
Jpac provides safe filtering of 15khz, addition of arcade controls, and it’s easy to make or buy a Jamma harness. It’s not required, but cleans things up well.
-
Thanks again for the reply @keilmillerjr
I've already got a MINI-pac, wouldn't that do the same thing, control wise, as the jpac? What exactly would the jpac be adding to the mix? Would it just be the filtering you mention?
-
Just as a follow up, I've been onto Andy at Ultimarc and he's unaware, in this instance, of the need for a jpac too. If anyone could shed any light on what it might add I'd appreciate it. They're quite pricey things so if I can just get away with a VGA666 and a breakout cable, that would be preferable.
Also regarding the breakout cable, Ultimarc sell one, but they also sell a variant called a Arcade Monitor Video Amplifier cable. Does anyone know if this would be a better cable to buy? Perhaps the signal from the pi is weak in some way and might benefit from this cable? Or would the standard one be sufficient?
-
Just as a follow up, I've been onto Andy at Ultimarc and he's unaware, in this instance, of the need for a jpac too. If anyone could shed any light on what it might add I'd appreciate it. They're quite pricey things so if I can just get away with a VGA666 and a breakout cable, that would be preferable.
Also regarding the breakout cable, Ultimarc sell one, but they also sell a variant called a Arcade Monitor Video Amplifier cable. Does anyone know if this would be a better cable to buy? Perhaps the signal from the pi is weak in some way and might benefit from this cable? Or would the standard one be sufficient?
You will likely need the amplified signal cable. It’s not necessary with jpac. Jpac has filtering so you can’t mess up your monitor. So long as you make sure your set 15khz, all good. Since you already have the mini pac for controls, I would just get the amplified signal cable.
-
Thanks again @keilmillerjr The amplified signal cable seems to rely on the standard pin outs of a VGA plug. From the website here http://www.ultimarc.com/vidamp.html (http://www.ultimarc.com/vidamp.html)
it needs pin 9 to carry 5v. Do you know if the VGA666 has this standard arrangement?
Also, I've been scouring the net for information on how 'exactly' you get the vga666 to output 15khz and I've drawn a blank. Are people positive this can be achieved? If so could they post where they've seen it and a breakdown of how it was done? I presume it's handled by some lines of code, but again, I can't find this anywhere. ???
-
This video shows it running at 15khz and in the comments he has included the timings he used in his config.txt
https://www.youtube.com/watch?v=gjUBQKyeWlQ (https://www.youtube.com/watch?v=gjUBQKyeWlQ)
Unfortunately the knowlebase he has created doesn't appear to be online anymore.
Hope this helps
-
I've used a VGA666 GPIO hat and the Ultimarc breakout cable with good success....albeit the wire gauge is a little small for my liking.