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Arthrimus

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With the recent free release of the universe bios 4.0 with the PICKnMIX I finally decided to purchase a 161 in 1 Neo Geo multi cart. PICKnMIX is a great feature, but I have discovered an issue with it that needed a fix. (This is not actually an issue with PICKnMIX it'self, but rather an incompatibility with certain setups. Razoola did a great job with the Universe Bios 4.0)

PICKnMIX must be enabled by holding the start button during the splash screen every time the Neo Geo is powered on. The problem I've found is that when using my Neo Geo on my New Net City with @invzims Jammafier it takes too long for the JVS I/O to initialize and I can't press the start button before the splash screen is already past. My solution, as with most things, was to write up a small program on a microcontroller to hold the start button for a couple of seconds at bootup then release it indefinitely. You can manually turn it on or off as needed using a switch.

This could also be helpful for people who are just lazy and don't want to bother with holding start every time they power on their Neo Geo (I can't say I wouldn't be one of those people too).

Here's the prototype.
12rdIgq.jpg


As you can see I'm tapping into the pullup resistor arrays for the button inputs to access the start button, GND, and VCC. I have a NEO-MVH MV1A and I've designed a little PCB that will fit right over the pins of the resistor array for a more elegant solution.

LZ2iVcV.jpg
9Lg9zwj.jpg


It's specifically set up for the MV1A because that's the only Neo Geo PCB that I have access to, however if someone could check the pinouts of the resistor arrays of other Neo Geo motherboard types I might also be able to accommodate those. I just need to know where P1 Start, VCC and GND pins are on those other motherboard revisions and I can see if the design will fit.
 
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This is a great idea. I've been using the select button (technically button 5 on a supergun) to trigger pick n mix to avoid start button conflicts.
 
This is a great idea - I also struggle with the hold down start button approach. When might this be available and any idea how much?
Looking forward to it. Thanks.
 
I haven't had this problem. I was super excited reading the thread, hoping it was going to conclude with a work around the need to use coin as select on 1 slot boards.
 
This is really useful if your power button/plug/extension cable and start button aren’t within arms reach of one another :thumbup:
 
I don't have a good reason for wanting this other than because I am a lazybones.
 
Could someone who has a an MV1B, MV1C and/or MV1FZ and a multimeter do me a favor and probe out the pullup resistor arrays for the button inputs near the JAMMA edge and tell me where P1 start is located on them? Pictures would help a lot as well. I'm trying to find out if this design might work on other MVS revisions besides the MV1A that I have, and if not, how it might be able to be adjusted to accommodate other models. Many thanks.
 
Thanks a lot @nem based on these photos I think this board will fit all of these models just fine. It looks like on the MV1B and MV1FZ you will need to trim the legs of the other resistor arrays in the area in order for it to fit, but otherwise the pinouts match.
 
Do you know if it will work with the MV-1 motherboard? To clarify - does this require any soldering or does the PCB simply fits over the resister pins without any actual soldering? How difficult is it to install with the $9.99 version if one isn't that seasoned with soldering or PCB work? I am definitely interested! Thanks.

http://www.hardmvs.fr/html/MV-1.php
 
If you (or someone else) makes it plug'n play solution (or confirms that current one works as is) with MV1C I will take one!
 
It would need to be soldered but it's not a complicated soldering job.

One could make a jamma MVS passthrough, with this device pre-fitted and a few other goodies attached to make it worthwhile. Such as a voltmeter and such.
 
It would need to be soldered but it's not a complicated soldering job.

One could make a jamma MVS passthrough, with this device pre-fitted and a few other goodies attached to make it worthwhile. Such as a voltmeter and such.
maybe with an auto fire function 8o
 
Based on the info provided by @nem I have put together some mockups of what installation on other boards should look like.

MV1B:
bRbYG3F.jpg

It looks like the only special consideration for the MV1B is that the legs on the resistor array above the one we are installing on will need to be trimmed down.

MV1C:
D4bzvFO.jpg

It doesn't look like there will be any issue installing on the MV1C

MV1FZ:
847e9HQ.jpg

Like the MV1B the legs of the resistor array above the one we are installing on need to be trimmed, but it looks like the shielding on the back of the board may need to be moved or trimmed a bit to make room for the PICKnMIX Fix PCB to fit vertically.

At this point none of the above installs have been attempted, but assuming the pinouts are correct there should be nothing stopping them from working.
 
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