WIP: Another PI JAMMA Adapter

I should clarify the resolution is running at CGA 15Khz.

The picture on my first post of Jungle Hunt is a VGA monitor, but
I am piping the signal through a GBS 8200 converter.

JD
 
I should clarify the resolution is running at CGA 15Khz.

The picture on my first post of Jungle Hunt is a VGA monitor, but
I am piping the signal through a GBS 8200 converter.

JD



.....by the power of grey skull.....
 
Can someone explain why this is a thing?

You have the VGA adapter on it - to hook it to a vga monitor (so dont need the jamma adatper there)

connecting the controls through the GPIO - so dont need the jamma there..

what purpose does this serve.. im obviously missing something.

A pi, with a $6 keyboard encoder, $15 vga666 on its own, and a speaker.. and you are under $100

im confused.
 
Can someone explain why this is a thing?



You have the VGA adapter on it - to hook it to a vga monitor (so dont need the jamma adatper there)



connecting the controls through the GPIO - so dont need the jamma there..



what purpose does this serve.. im obviously missing something.



A pi, with a $6 keyboard encoder, $15 vga666 on its own, and a speaker.. and you are under $100



im confused.



The vga666 adapter uses the gpio pins. I would argue that's the part you don't need since pi can output cga and vga resolutions natively. But this solution is fine and works.

You still need to adapt to JAMMA for controls in a real cabinet. So that's why this is a thing.
 
The vga666 adapter uses the gpio pins. I would argue that's the part you don't need since pi can output cga and vga resolutions natively. But this solution is fine and works.

You still need to adapt to JAMMA for controls in a real cabinet. So that's why this is a thing.

No you dont.. you can plug the controls directly to a usb encoder that usb's into 1 of 4 ports on a PI.

so. again.. WHY is this a thing?
 
It was pointed out that I missed a few things about the adapter the first few read throughs.. nevermind - this is awesome.. my fault.. thus the reason I asked why.. I obviously missed that it will connect to standard and med res monitors, and the built in AMP for pushing the speakers.. awesome.
 
It's not VGA, it's standard res RGB or medium res RGB.

It's Plug & Play JAMMA ready so you won't be cutting and splicing
all those wires to patch in your amplifier, keyboard encoder
and power supply.

Possibilities exist for a System 16 and Capcom pinout version.

It has a built in audio amplifier.

Unlike the GPIO pins, the inputs are all buffered so no
blown PI's or CPU.

It's made by me so it's going to be awesome.



Can someone explain why this is a thing?

You have the VGA adapter on it - to hook it to a vga monitor (so dont need the jamma adatper there)

connecting the controls through the GPIO - so dont need the jamma there..

what purpose does this serve.. im obviously missing something.

A pi, with a $6 keyboard encoder, $15 vga666 on its own, and a speaker.. and you are under $100

im confused.
 
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No you dont.. you can plug the controls directly to a usb encoder that usb's into 1 of 4 ports on a PI.

so. again.. WHY is this a thing?

Um, no you can't without another adapter or wiring modifications.
 
vga666, you guys say?

Looked it up. Sounds interesting. I have a pi3+ sitting here, maybe have to try it. is there a good US source for it?

The Gert VGA 666 (6 bits per colour channel, hence 666) is a breakout/add-on board for the Raspberry Pi Model B+ (will not work with Model A/B as the additional GPIO pins on the Model B+ are required). It is an open source hardware design recently released publicly by Gert van Loo who was one of the hardware engineers that was instrumental in the initial design of the original Raspberry Pi (also one of the chip architects on the BCM2835 chip at the heart of the Raspberry Pi) and someone that many of you may have spoken to at Raspberry Jams or on the Raspberry Pi forums. It is a neat and very useful solution for using a VGA screen/monitor with your Raspberry Pi and is far cheaper than an HDMI to VGA adapter or similar. The VGA connection is driven natively in hardware over the GPIO pins (using a parallel interface) and uses around the same CPU load as the HDMI connection on board. It is capable of displaying 1080p60 VGA video with no CPU load. It is also possible to drive this interface at the same time as the HDMI connection, so a dual screen setup is also possible. This add-on was not possible on the Model A and B pis, because not all of the required pins had been brought out to the GPIO header. Yet another awesome upgrade that the Model B+ has allowed for
 
So if I am understanding this correctly, this will basically do what the Arpicade's does but more? I have been on the fence for a while now on purchasing an Arpicade but I just don't like the price. It's been at $145 forever. If your board comes in under $100 then I will be all over it.

Your contribution to the hobby is very much appreciated! I love my raspberry pi3 and to have it connected to a CGA CRT would be awesome! Thanks.

Robert
 
I should clarify the resolution is running at CGA 15Khz.

Do you support Native Resolution and refresh rates for each game?

One of the things that really disappointed me with the ArPiCade was that they simply scale everything to 240P 60Hz which isn't correct for a lot of games (for instance Pac Man should run at 224 x 288 60.6Hz, and mortal Kombat should run at 400x254 53.2Hz)

^This IMO is what separates a crap multi-board from a good multi board.

The only Pi board I know of that does support native resolution an refresh is the RPi2JAMMA: http://www.neo-arcadia.com/forum/viewtopic.php?t=54733 Unfortunately they guy who makes them won't sell them outside of Europe.

Two other suggestion.
1. include a standard CPS1 or CPS2 style "kick harness" header for buttons 4-6. Most games that use more than 3 buttons use one of these connectors and it'd be nice to have on a Pi based board instead of the crappy ChAMMA (Chinese JAMMA) pinout where they shove those buttons on the JAMMA edge. Fighting game fans will really appreciate this.

2. Instead of a 3.5mm audio jack include un-amplified RCA jacks for stereo audio. This is the standard for JVS so it's what a lot of arcade PCBs (and thus a lot of cabs) are already setup for if they support Stereo Audio. having a 3.5mm audio header isn't bad since you can just run an adapter, but it's nice to be able to run a PCB that plugs into your existing cab with as few adapters as possible.

If you really want to go all out then add some konami style headers for players 3 and 4 so that people can use these in 4 player cabs as well.
 
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Resolution is controlled by the Pi. You set your timings in the config.txt
file located at /BOOT

I've received a lot of suggestions about headers, add on ports, etc. The problem
is that it adds on to the size and cost of the board. I think right now the best
way to do this is an adapter board that would plug into the extra inputs connector
in the center of the board. This way someone wants to and a CPS connector doesn't
need a different Jamma/PI board. I also have thoughts for an add-on Sanyo EZ20 inverter
board since I don't think the Pi will invert the colors. It can be done on the existing board
but would add on some cost and real estate.

The 3.5mm jack is strictly and input to the audio amp on the board. The audio
amp sends its output to pin 10 and pin J on the Jamma connector.

Do you support Native Resolution and refresh rates for each game?

One of the things that really disappointed me with the ArPiCade was that they simply scale everything to 240P 60Hz which isn't correct for a lot of games (for instance Pac Man should run at 224 x 288 60.6Hz, and mortal Kombat should run at 400x254 53.2Hz)

^This IMO is what separates a crap multi-board from a good multi board.

The only Pi board I know of that does support native resolution an refresh is the RPi2JAMMA: http://www.neo-arcadia.com/forum/viewtopic.php?t=54733 Unfortunately they guy who makes them won't sell them outside of Europe.

Two other suggestion.
1. include a standard CPS1 or CPS2 style "kick harness" header for buttons 4-6. Most games that use more than 3 buttons use one of these connectors and it'd be nice to have on a Pi based board instead of the crappy ChAMMA (Chinese JAMMA) pinout where they shove those buttons on the JAMMA edge. Fighting game fans will really appreciate this.

2. Instead of a 3.5mm audio jack include un-amplified RCA jacks for stereo audio. This is the standard for JVS so it's what a lot of arcade PCBs (and thus a lot of cabs) are already setup for if they support Stereo Audio. having a 3.5mm audio header isn't bad since you can just run an adapter, but it's nice to be able to run a PCB that plugs into your existing cab with as few adapters as possible.

If you really want to go all out then add some konami style headers for players 3 and 4 so that people can use these in 4 player cabs as well.
 
One of the things that really disappointed me with the ArPiCade was that they simply scale everything to 240P 60Hz which isn't correct for a lot of games (for instance Pac Man should run at 224 x 288 60.6Hz, and mortal Kombat should run at 400x254 53.2Hz)

This just isn't true.
Currently ARpiCADE supports 240p@60, [email protected], 256p@56, 288p@50 and others can be added too.
 
Proto #2 up and running tonight !
 

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So this is awesome - I will be needing several of these if you decide to produce a few more to sell.

One thought/question - would there be a way to build an adaptor board like this that doesn't rely on the GPIO pins? That could convert an hdmi signal directly to CGA standard or Medium Res? Something more plug and play/ universal - so it could be used with a Rpi, PC or some of the more powerful SBC's?

I ask because it seems like there seems to be alot of interest gathering for other boards like the ODroid XU4 and ASUS Tinkerboard since the Raspberry pi foundation has said there won't be a significantly more powerful Pi coming out for several years. Its possible the emulation community might start moving their efforts to more powerful SBCs if they feel like the Rpi platform will become stagnant. I believe RetroPie already has an official distribution for the Odroid XU4.
 
thanks for your work

Glad you're producing a solution that uses the native GPIO outputs. I imagine other jamma pi products must be introducing some output lag by going through the active HDMI video conversion step.

Of course, I don't know that for sure so someone please correct me if that's an unfair assumption. My hunch has always been that this is the right way to go about it, and if accurate, it will definitely be a selling point.

Either way, congratulations on a successful R&D. I will support with a purchase when it's ready.
 
A decent HDMI to analog video converter will run in the hundreds
of dollars. The cheaper units are slow and produce poor quality video.

The great thing about the video through the GPIO pins is that there
is no lag or delay. The output I've seen is absolutely amazing.

The idea right now is to keep it affordable. I've considered an HDMI to
analog converter but there is no way to do it properly and keep it cheap.

JD


So this is awesome - I will be needing several of these if you decide to produce a few more to sell.

One thought/question - would there be a way to build an adaptor board like this that doesn't rely on the GPIO pins? That could convert an hdmi signal directly to CGA standard or Medium Res? Something more plug and play/ universal - so it could be used with a Rpi, PC or some of the more powerful SBC's?

I ask because it seems like there seems to be alot of interest gathering for other boards like the ODroid XU4 and ASUS Tinkerboard since the Raspberry pi foundation has said there won't be a significantly more powerful Pi coming out for several years. Its possible the emulation community might start moving their efforts to more powerful SBCs if they feel like the Rpi platform will become stagnant. I believe RetroPie already has an official distribution for the Odroid XU4.
 
Glad you're producing a solution that uses the native GPIO outputs. I imagine other jamma pi products must be introducing some output lag by going through the active HDMI video conversion step.

Of course, I don't know that for sure so someone please correct me if that's an unfair assumption. My hunch has always been that this is the right way to go about it, and if accurate, it will definitely be a selling point.

Either way, congratulations on a successful R&D. I will support with a purchase when it's ready.

Actually the method used by RaspberryJAMMA/ARpiCADE adds less than 1 frame of lag. As long as you arn't doing any scaling or other image processing and are only converting digital 240p to analog 240p there is no need for a framebuffer or any other type of lag inducing steps.

Sorry I don't mean to derail the thread PCJohn.
 
Actually the method used by RaspberryJAMMA/ARpiCADE adds less than 1 frame of lag. As long as you arn't doing any scaling or other image processing and are only converting digital 240p to analog 240p there is no need for a framebuffer or any other type of lag inducing steps.

That's good to know. Thanks for setting me straight and assuaging my concerns. I appreciate your expert knowledge.
 
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