R8, R9, R10
Minigun Supergun - An Open Source Supergun
- Thread starter Frank_fjs
- Start date
zionfarm
Professional
No, sorry, I thought you had the standard edition with fixed resistors. Disregard everything I've said.
Adjust the pots!
Adjust the pots!
This is how the next version is shaping up.
Button 5 now supported from the jamma edge and a dipswitch can be used to enable / disable buttons 4 & 5 from the jamma edge.
Other than that just trace / copper / silk improvements. More space between the mounting holes and components.
Button 5 now supported from the jamma edge and a dipswitch can be used to enable / disable buttons 4 & 5 from the jamma edge.
Other than that just trace / copper / silk improvements. More space between the mounting holes and components.
Have you considered removing the 8 optional output capacitors?
I have tried the circuit both with and without them, and can’t see much of a difference in the output.
The datasheet for THS7374 has them as optional. Having them there is probably beneficial in some scenarios, but THS7374 boards ive seen for other usecases (RGB modding consoles and stuff) dont have them.
I have tried the circuit both with and without them, and can’t see much of a difference in the output.
The datasheet for THS7374 has them as optional. Having them there is probably beneficial in some scenarios, but THS7374 boards ive seen for other usecases (RGB modding consoles and stuff) dont have them.
ninjaz0mbie
Student
is it difficult to adapt this to support MVS wiring for stereo audio etc using dip switches?
https://wiki.arcadeotaku.com/images/2/27/JammaVsMVS-pinouts.pdf
https://wiki.arcadeotaku.com/images/2/27/JammaVsMVS-pinouts.pdf
MVS stereo audio is already supported.
pacoarcade
Professional
That capacitors are for AC coupling. It's considered a good practice to include them.
I've removed ceramics C9,C10,C11,C12 though and I don't notice any difference.
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I'm inclined to leave the capacitors there. I'm not taking short cuts on an open sourced product, but if you feel you don't want the caps there you can always leave them off the PCB. The circuit will still operate without the 0.1uFs, you will however need to bridge the pads of the radials.
I do notice a subtle difference without the caps. Brightness fluctuations on things like flashing text (e.g. insert coin). Results may vary pending monitor and what other devices you have in the chain such as the OSSC.
I do notice a subtle difference without the caps. Brightness fluctuations on things like flashing text (e.g. insert coin). Results may vary pending monitor and what other devices you have in the chain such as the OSSC.
pacoarcade
Professional
Do you notice a difference using only radials and without C9,C10,C11, C12 ceramic caps?
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Without the radial caps, which are C1, C2, C3, C4.
The ceramics are C9, C10, C11, C12.
The ceramics are C9, C10, C11, C12.
Ah, this is a very fair point. I've been pretty much only using OSSC for THS7374 outputs, and there I don't really see much of a difference at all when using DC coupled outputs.
OSSC obviously does a bit of additional filtering of the signal though, so maybe that makes sense.
Probably better to do it like the current Minigun design for for general purpose use
I've used Franks 4P PCB in a different way. Just wired up 3P and 4P direct to a 34pin CPS2 fitting. I had to also wire in a GND as there was no other way I was able to get GND - @Frank_fjs maybe you could wire GND and 5V to some of those spare through-holes in the middle of the PCB for others who want to do this.
i have no 2P coin button
so 3 players for now
in all its glory
sega sticks modified with DB15
I also like to wire up a removal rip cord for the header so I dont have to pull on the cables.
thanks Frank, cool PCB
i have no 2P coin button
so 3 players for now
in all its glory
sega sticks modified with DB15
I also like to wire up a removal rip cord for the header so I dont have to pull on the cables.
thanks Frank, cool PCB
That's cool!
Good idea re adding a header for ground / power, this way the 4P pcb can be used detached from the Minigun.
Good idea re adding a header for ground / power, this way the 4P pcb can be used detached from the Minigun.
I'm hoping I have just fundamentally misunderstood what I need for this to work, but I'm failing to get any video out of the Minigun hooked up to an MV-1C. Does the RGB SCART output require something like the OSSC/Framemeister or the RetroTINK RGB2COMP in order to convert properly to consumer-level displays?
I was avoiding the OSSC for now because I didn't need that level of quality (or complexity of configuration), but maybe my total lack of exposure to SCART before this project means I've misunderstood what is needed to get a picture on a display. I have tried a cheap SCART-to-composite adapter hooked to an old Sony consumer CRT without luck. I then tried plugging it in to a SCART-to-HDMI video converter instead, but still no luck. When I boot it up, it just scrambles the on-screen display of the HDMI converter.
I put together a short video of the setup totally failing to work, if there is something obvious I've missed.
For my setup, I've built my v1.7 Minigun. I have the Minigun connected to a totally unmodified MV-1C with a 161-in-1 cart. I connected a Happ power supply (outputs on the Molex pins all seem correct). I have an NES RGB SCART cable that I'd seen others recommended for getting video output to SCART. From the SCART output, though, I'm not totally sure what I can get away with.
I wish I could just swap out the JAMMA board for a known-working one, but this is my first adventure into arcade boards. I only assembled the one Minigun, so I don't have another known-working supergun to swap in either. If nothing else, the v1.7 assembly was a lot of fun. I've done other surface-mount projects before, but for some reason this was just a blast to put together. I really hope I can get it all working happily, but I've still had fun learning.
I was avoiding the OSSC for now because I didn't need that level of quality (or complexity of configuration), but maybe my total lack of exposure to SCART before this project means I've misunderstood what is needed to get a picture on a display. I have tried a cheap SCART-to-composite adapter hooked to an old Sony consumer CRT without luck. I then tried plugging it in to a SCART-to-HDMI video converter instead, but still no luck. When I boot it up, it just scrambles the on-screen display of the HDMI converter.
I put together a short video of the setup totally failing to work, if there is something obvious I've missed.
For my setup, I've built my v1.7 Minigun. I have the Minigun connected to a totally unmodified MV-1C with a 161-in-1 cart. I connected a Happ power supply (outputs on the Molex pins all seem correct). I have an NES RGB SCART cable that I'd seen others recommended for getting video output to SCART. From the SCART output, though, I'm not totally sure what I can get away with.
I wish I could just swap out the JAMMA board for a known-working one, but this is my first adventure into arcade boards. I only assembled the one Minigun, so I don't have another known-working supergun to swap in either. If nothing else, the v1.7 assembly was a lot of fun. I've done other surface-mount projects before, but for some reason this was just a blast to put together. I really hope I can get it all working happily, but I've still had fun learning.
the Goat
Grand Master
I use the minigun directly with my Sony BVM monitor -- no OSSC/Framemeister. But the BVM is not a consumer display.
ebzero89
Enthusiast
I've hooked my minigun to an RGB modded Trinitron using a MV-1FZ and it worked no problem, perhaps a bit of overscan but no real issues.
Well, that's really cool. I do have a pair of Trinitron TVs that could be modded at a later date. Currently, though, I am really hoping to get this rolling with a stock TV before I spend too much time going RGB-crazy. If this ends up a win, though, I'll probably go plenty crazy later.
There's no special requirement.
I'd recommend checking your soldering, especially the THS7374 chip and check voltages with a multimeter, make sure you're getting +5V where required.
I'd recommend checking your soldering, especially the THS7374 chip and check voltages with a multimeter, make sure you're getting +5V where required.
Barth0lin0
Professional
Yes. Consumer TV don't accept RGB signals. So a OSSC or a RGB2COMP or a supergun that can use a Genesis HD retrovision cable is necessary.
Scart to composite adaptor is on a RGB to composite converter so it's normal it doesnt work.
this could work but the those cheap converters processes 240p as 480i and also the MVS output @59.14Hz....this can explain why it looks like trash on your TV!
You have a good cable!
hope it helps you!
Simon