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Sega Model 2/3 A/B/C - CRX and how I stopped worrying and learned to love the bomb.

Psyko-M1

Psyko-M1

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Look at this thing! Look at it's glorious games!
How in the hell do I wire one of these up?
Well that's why I started this thread... I'm a n00b and wanna learn. Lets learn together.

I bought a Model 2B CRX and know nothing about it outside of that it looks like it's a thicc stacked juicy burger of sexy PCBs from SEGA .
These metal burger bath-tubs always intrigued me, and to say the least within a year or so, I'd love to assemble my own Model 2/3 SEGA multi driving setup, or perhaps collect a couple unreleased titles.

Untitled.png


It didn't occur to me how complex these seem to be, and can be quite imposing when you unpack it and go WTF.
I hope you're a glutton for punishment...
s20190318_175527.jpg


What do I do now?!?!?!
With that said I'm moving my information thought dump here so I can ping you good folks for help.
Now as it stands there's multiple ways of connecting this thing up.
(Yes I know there's other sub threads in other places, but this is now in one place)

sega_model2_a_pcb_arcade_filter_board_pinout.gif

Edit
sega_model2_b_c_pcb_arcade_filter_board_pinout.gif

sega_model3_pcb_arcde_filter_board_pinout.gif

1160.gif


Don't make me hit a bitch with a Blast City!!!
dynamitecop-1.png


What are my options??? Jamma? JVS??? Japanese Harnesses???? LOLWUT?!?!

Blast city harness... I have a Blast City Cabinet.
https://page.auctions.yahoo.co.jp/jp/auction/k374885579
img_2510.jpg
"I've never understood why wire is so expensive." @twistedsymphony

part number 600-6738-20
I'm not sure if model 2 got it's own loom, but they're nearly identical
the top section plugs into your board, and the bottom section plugs into the Blast's IO board,

Then I saw this thing from Hong Kong...
https://www.ebay.com/itm/Sega-Harne...e-Out-V-F-Arcade-PC-Board-28-Pin/182049587191
s-l1600.jpg
Interesting and I'm sure it'll work with most units.


Also, here's a nice compendium of VOLTAGE Differences and Notes:
The biggest difference is that Model 3 requires 3.3V power (similar to newer JVS boards) while Model 2 only uses 5V so the power supply will need to be upgraded to a model that provides a 3.3V power source.

There are really 2 connections that need to be changed when going Model 2->Model 3.
1. The Main Power Connector:
Model 2 has 3 10-pin connectors for 5V power, 5 pins for 5V, 5 pins for ground on each of these (CN1, CN3 and CN12 on M2A and CN9, CN10, and CN11 on M2B/M2C).

Model 3 uses one of these 10-pin connectors for 5V power (CN14) and also has a large 24 pin connector (CN13) that includes 8 3.3V lines, 6 5V lines and the rest of the pins are ground. you could re-pin one of the 5V connectors from model 2 to populate half of this connector and then fill out the rest of it with fresh lines for 3.3V. In my case I'm leaving the two extra 5V connectors from Model 2 disconnected and simply adding a whole new connector for the 3.3V/5V connectors that Model 3 requires so that I can easily swap back to Model 2 if I so choose.

2. The Fan Connector:
Model 2 has an externally mounted 12V case fan that uses a 2-pin Molex connector going directly to the fan (not in the diagram), Model 3 has 2 internally mounted 12V case fans that receive their power through a 3-pin JST NH connector on the filter board (CN16). For this I made a simple adapter cable with a 3-pin NH connector on one end and a Molex connector on the other end. This makes it plug and play, and keeps me from having to run new 12V wires while reducing the number of unused connectors.

*A Note about the 5V output connectors
Model 2B/2C and Model 3 all use the same 11-pin connector for 5V output (the additional pin makes it easy to tell apart from the 10-pin input connector). Model 2A has a 11-pin 5V output connector too, however Model 2A also has an additional 9-pin 5V output connector. that the later boards are lacking. This seems to be the biggest compatibility difference between Model 2A and 2B/2C.

All other connectors should be pin-compatible.

I will say that the audio connectors were listed has being pinned differently in nearly ever manual I cam across, even the audio connector on one of my Model 2 boards (just one) was plugged in backwards, which I confirmed by metering out the ground pins. so I'm least confident in that connector (though worst case is they L and R are swapped or it's out of phase).

Most pinouts for the 25-pin digital control connector that I found online were wrong when compared against the service manuals and against my own machine wiring. so it would be nice to get confirmation on that connector from another working setup.


EDIT 11062019: Stolen from a recent post from TS... Appending to this thread.

SUPERGUN Model 2????
Concerning powering a VF2 Model 2 to a Supergun.
Proper voltage wasn't allowing the unit to boot.
This is the fix.


you take the ATX connector pinout:
atx-pinout.png

To force the ATX PSU on you need to hook "PS_ON#" to any of the "COM" (AKA Ground) pins.
then you run the rest of the wires to the correct pins on the model 2 board power connectors:


the hard part is the fact that there are only 5 +5V pins on the ATX connector and there are 15 +5V input pins on the Model 2 filter board. The filter board uses JST NH connectors which only support up to 22awg wire I believe. so what you'll want to do is crimp 2 22awg wires together on each 5V pin of the atx connector so that you have enough to fully populate the model 2 connectors. and then start tapping +5V pins on other connectors on the power supply, if there are CPU and GPU power connectors use those and failing that you can start using the 4-pin "molex" connectors.


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Footnotes:

I got a lot to put here, but if you have anything else of use, go ahead and toss it in.
I can't seem to source manuals or wiring diagrams for most of this stuff.
Thank you for @twistedsymphony for piquing my interest in kicking the tires on one of these.
 
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twistedsymphony said:
it looks like you have a Model 2C PCB so all you really need is this pintout:
sega_model2_b_c_pcb_arcade_filter_board_pinout.gif


and then match all of the pins to the pinout here: https://wiki.arcadeotaku.com/w/Sega_Blast_City_Wiring_Guide#Cabinet_I.2FO_board

the rest of the information in your "dump" is just noise.
Click to expand...
Well, I'm far from done, but i'll be using this space to mess with.
With concern to trying to also build a harness for a supergun, all of this will prove useful.
Thank you for the help and pointing the way.
 
my wave runner runs on a Model2 the wiring in that thing is VERY VERY impressive to say the least haha
 
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I guess this confirms that Virtual fighter 3, the first model 3 game, does not use midi :

IMG_1497.jpg



oh seeing that the JST-RA connector is out of stock, if found at all, anywhere, I just found that a good old ribbon cable floppy connector actually is the perfect fit on CN5 of a blast city.
 
Mrhide said:
IMG_1536.jpg
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This is gangster, but it works.
Lord knows I've harvested a floppy cable or two in the last year.
Enjoy that VF3.
I wonder how much better it looks over the Dreamcast.
The last time I played VF3, it was at the Luxor in Vegas right after I turned 21.
They had this monster large projection screen cabinet.

Enjoy that shit.
VF3 is a killer game, and one of the best in the series next to part 2.
The later releases 4 on just don't do it for me.
 
psykom1 said:
Enjoy that VF3.
I wonder how much better it looks over the Dreamcast.
Click to expand...
technically the Dreamcast is a higher performance system than Model 3.

If you look at Virtual On OT on the Model 3 hardware, versus the version that was later released on Dreamcast and NAOMI the DC/NAOMI version is higher resolution with higher res textures and some nice Anti Aliasing but has worse particle and lighting effects. this is because the Model 3 had some particle and lighting features that the DC hardware lacked, so they just cut them out when porting the game. It's entirely possible they did this with VF3 also... it's also possible that with VF being a flagship franchise for Sega they took the time to make use of the other advanced features the DC offers.

utilizing both system to their fullest DC games should always look better than Model 3 games, but given that the game was originally developed for Model 3 that might not be the case; just like with VOOT.
 
psykom1 said:
This is gangster, but it works.Enjoy that shit.
VF3 is a killer game, and one of the best in the series next to part 2.
Click to expand...
Gangster is my middle name! 8)

gang.JPG



The sound is super nice on the game. Really enjoying it!



"Can be converted/upgraded to Virtua Fighter 3: Team Battle by using a ROM upgrade kit. A simple ROM swap adds new features, a team battle mode and various tweaks and adjustments to the fighting engine, making the game far more balanced."

So anybody actually did this? the vf3tb mame set has 8 roms:


epr-20126.17
epr-20127.18
epr-20128.19
epr-20129.20
mpr-20130.1
mpr-20131.2
mpr-20132.3
mpr-20133.4

Guess I'll need to order some blanks ... xiaobao_semi on Ebay ok ?!
 
Maybe this can be usefull to somebody:


It's the blast city CN5 pinout to the system3 pins and the last 2 rows with the highlighted yellow is the floppy pinout.


system3_cn5_floppy.png
 
the "CAB IO" board on the Blast City uses a JST RA connector, which seems to match the connector for a floppy drive ribbon cable including the key pin.

Though, I'm still not entirely sure how this information is useful since it still needs to be routed to a model 2 or 3 filter board or JAMMA or something else.
 
twistedsymphony said:
. it's also possible that with VF being a flagship franchise for Sega they took the time to make use of the other advanced features the DC offers
Click to expand...
It's just a shame that SoJ mishandled that flagship title on the DC. If AM2/Yu Suzuki (the genius) had made the game as they should have, it would have been better than it was.

They even went behind Yu's back and had another team make the game whilst he and AM2 were hard at work on the Saturn "miracle VF3 port". I really wish SEGA had stuck to that idea and released the DC later. If it released in late '99 with a DVD drive, things would have been very different. A SS upgrade should have happened in late '96 early '97 to keep up with the PS1. A co-processing cart to enhance the 3D capabilities of the SS would have been PERFECT! Especially releasing with VF3.

It was only early 97 that the PS1 started smashing the SS, thanks to that p.o.s game called FFVII. God I can't stand that game or that dickhead that made it and ruined the series. FFVI was one of my favourite games of all time, VII was such a disappointment. Obviously all my comments relate to Japan. I knew nothing outside the Jp market thankfully, because I bought a Jp SS in early '95 and bought Saturn Fan every fortnight.
 
My Virtua Fighter 3 sounds like a jet engine. Is there an adapter I can get for regular case fans or will I need to make one myself?
 
First apologies if it's not appropriate for me to be reviving this thread, but I've been actually using the guide from this to work on my project.

I recently picked up a Fighting Vipers system and it seems to be working fine after using the Model 2B/2C picture from @Psyko-M1. It has been super helpful, and even though I am not an expert with all of this, I eventually got it to power up with sound and video without any issues after quite a few attempts.

I don't know much about video signals unfortunately, but I assume there is something that either I'm not doing right, or I need an additional converter to make this work with my SuperGun MAK Strike that I have via Jamma. That SuperGun then outputs to SCART, which I then have a SCART to COMPONENT converter so it works on my Sony Trinitron.

So overall this setup has been working fine for other systems (older single board games and my Naomi system I have), but unfortunately with this game I am getting multiple vertical images out of sync. I have it properly wired for the RGB Sync and RGB GND, so I'm wondering if there is a DIP switch I should be setting for the resolution, or if I should disconnect just the video from the Jamma connector and then connect it to some other output converter to go component out? Here's a quick video of what I'm getting. Any help would be greatly appreciated.

Fighter Vipers Video Sync Issue
https://streamable.com/2dqmfr


Thank you for your time everyone.
 
Model 2 outputs medium resolution (24Hz) . Your TV is standard resolution (15Hz).
 
aphonia said:
I don't know much about video signals unfortunately, but I assume there is something that either I'm not doing right, or I need an additional converter to make this work with my SuperGun MAK Strike that I have via Jamma. That SuperGun then outputs to SCART, which I then have a SCART to COMPONENT converter so it works on my Sony Trinitron.

Thank you for your time everyone.
Click to expand...
Correct, the video out of a Model 2 is 24K.
You seem to have everything down but you will need to throw it at an OSSC or a scaler to translate the signal.
Your PVM/CRT looks like it doesn't support it.

Plus you shouldn't apologize for necro-commenting on a thread. That's what it's good for. Helping others.
Glad the information here is found useful.
 
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