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Hi guys,

Does anyone know about this small PCB that came inside the upright UK cabinet of Sega Rally 1995? This particular cabinet used a 2-way shifter going to that PCB, and appears to convert the data of 3 switches (pins 13, 14, and 15 of the 25pin connector), which the game used in the Twin and DX versions for 4speed manual transmission on an h-gate shifter, to sequential up/down data (ex. up->2, down->1, up->2, up->3, down->2)

Well I bought one off Videotronics UK to see if I could use it for a Mad Catz MC2 racing wheel, considering it uses a 2-way shifter like on the upright cabinet. Wonder if this will work with even the Model 3 racers like Daytona 2 and Super GT. It would warrant a handy tool to have in order to play MT in those drivers if so, but I heard since they're solely 3 switches it will sacrifice MT in sequential games like Indy. I could not easily find a manual or wiring schematic for that exact cabinet, unfortunately.

Here's a photo of what I'm referring to, and unfortunately I have no pics of mine since I'm on vacation until the 12th. This photo belongs to Kev A of the UKVac forum, so credit entirely to him: http://www.ukvac.com/forum/uploads/3820/aaaa6.jpg (it is the mounted PCB with 4 white feetscrews). The same user did show a brief wiring diagram of where the connections on the top connect to on the filter boards, however, in the same thread, so maybe something's possible to get going here. :) It looks like there's some ground wires for the shifter that go to the 11-pin output connector on CN2 in M2A. I haven't actually used that output connector at all when wiring my own controllers, though this would be my first time attempting a wheel with pedals.
http://www.ukvac.com/forum/indy-500-in-sega-rally-upright_topic367321.html
-Paul
 
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nem

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I have two of these in my upright Sega Rallys. I see no reason why it couldn't work with other Sega 4-way shifter games. I'm pretty sure they all follow the same logic.
 
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I have two of these in my upright Sega Rallys. I see no reason why it couldn't work with other Sega 4-way shifter games. I'm pretty sure they all follow the same logic.
I'm likin' the sound of this already. PM sent. :)
 

nem

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EP1339_b.jpg EP1339_c.jpg

Pinout for Sega Rally (Model 2A):

1 - +5V
2 - SHIFTER UP
3 - SHIFTER DOWN
4 - N/C
5 - N/C
6 - CN10 PIN 13 (1P DOWN)
7 - CN10 PIN 14 (1P UP)
8 - CN10 PIN 15 (1P RIGHT)
9 - N/C
10 - GND

I might have a crack at designing a repro board. Would be good practice for more involved projects.
 
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nem

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ep1339_repro_board.jpg


Made a repro board. It may work? EDIT: confirmed working by @waiji in post #19.

Parts list:

Code:
H1		2.54mm 10-pin header
D1-D8	1N4148 signal diode
R1-R2	1K resistor
R3-R6	10K resistor
C1-C2	0.47uF cap
U1		74HC14
U2		74HC193
U3		74HC03
 

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nem

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6 - CN10 PIN 13 (1P DOWN)
7 - CN10 PIN 14 (1P UP)
8 - CN10 PIN 15 (1P RIGHT)

I checked how Sega Rally and Daytona USA 2 work, and they both work the same.

1st gear is DOWN + RIGHT
2nd gear is UP + RIGHT
3rd gear is DOWN
4th gear is UP
 
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EP1339_b.jpg EP1339_c.jpg

Pinout for Sega Rally (Model 2A):

1 - +5V
2 - SHIFTER UP
3 - SHIFTER DOWN
4 - N/C
5 - N/C
6 - CN10 PIN 13 (1P DOWN)
7 - CN10 PIN 14 (1P UP)
8 - CN10 PIN 15 (1P RIGHT)
9 - N/C
10 - GND

I might have a crack at designing a repro board. Would be good practice for more involved projects.
Great stuff. I'll keep note of this and may fashion some connectors to get this powered up if I ever get the MC2 wired in the coming months. I think I could possibly plug some single black JST connectors in them, since the old school CD-ROM audio cable fits into the NH female connectors from what I've tried.

Took the time and effort to do a repro too, huh? Great work. I'm surprised this small little board has RARELY been discussed. Thank you. ;)

BTW, does N/C mean "not used"?
 
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nem

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Not Connected

I haven't really thought of it before, but I do see the value of one if you wanted to run multiple games in one cabinet. If I added a +3.3V PSU to my Sega Rally upright, I could play almost all Model 2 / 3 racing games on it.
 
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I haven't really thought of it before, but I do see the value of one if you wanted to run multiple games in one cabinet. If I added a +3.3V PSU to my Sega Rally upright, I could play almost all Model 2 / 3 racing games on it.
Come to think of it, I looked at the type of connectors that CD-ROM cable used and they look to be Dupont cables. Those would be ideal, possibly. Then it's a matter of giving that board 5v and ground power to the 11-pin (CN2) output connector, right?
Shouldn't be too hard as I found a useful guide here from aoiddr about his mod to JVS. :) The MC2 I plan using is the Universal Console version, yellow and black.
 
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So Friday and yesterday, I had a go at hooking the Mad Catz MC2 up and the SR1995 shifter board, and while I have power to the gear stick and the small board, I was only able to get gears 3 and 4 recognized in test mode on both this game and Daytona 2. I checked my connections and they all looked good.

I soldered some male Dupont cables to pins 13-15 on the 25-pin connector so I can easily swap back to sequential games like Indy 500 or Harley.
I've also used Dupont cables for the shifter PCB and all grounds for buttons to the output connector,, so my inputs and pots are definitely working.

Finishing this off, today I ended up frying the shifter PCB by accidentally misconnecting the 5v and ground. It got fiery hot and smelled absolutely HORRIBLE. I will be on the lookout for another one in the meantime, but anyone doing this mod PLEASE connect it in the order nem shows in the picture. Pins 1-10 should be in left to right order. Use a color to identify which is which. Lesson learned.

Side story: VERY EASY wheel to mod and highly recommend it, by the way. All you need to do is open the main wheel up and there is a green PCB with all the connections marked, so it's just a matter of cutting them off the circuit and knowing all the common grounds or which button is which.
The start & back buttons, plus the D-pad all share the same ground, so I wired the view buttons to the D-pad to keep the setup as simple as possible.
Pedals and shifter switches are both on the same PCB, with the brake pedal marked as "II", and gas marked as "I", though they do appear blurry on the circuit.
 

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So I found another one of those Custom Shifter PCBs shipped from UK and I'm actually going to try interfacing that with a wheel that uses hand pedals (I GREATLY prefer these to the foot pedals due to the cheap quality of them & they slide around) on my Sega Rally stack. I always use WHITE (which Sega used) for any digital/common grounds, and zip tie my wires into a single harness to my DB15 breakouts so it doesn't confuse me. I will also try leaving the +5V and GND connectors into the small board so I don't short it by mistake like I did last summer.
When I first hooked it up I was only able to get the 3rd and 4th gears recognized but I think I may have not connected it properly.
Side story: The Mad Catz MC2 has good, smooth pots but it takes up a lot of space, and I've thrown several of them out already (one was busted through transit :cursing:). Well now that I use DB15 cables for these and wrote my own diagrams, I have a better system of hooking these up to make it universal across all of my arcade stuff.
 
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This is really strange. I connected my 2nd one of these today, following the wiring and even daisy chaining the ground of the shifter PCB to the ground of my breakout board, using Dupont connectors. I still only get gears 3 and 4 recognized. Testing my Mad Catz PS1 wheel and I've done a combination of different buttons.
Can anyone help me out? This one has a broken pin but it's not for anything anyway. Trying on my Scud Race board.
 

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nem

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Looks like your wiring is fine, at least for the shifter board and the Model 3 filter board.

Are you sure your shifter board is working? I have two Sega Rally uprights and one of mine was broken. Had to replace two of the ICs on it.

Double check that the filter board is OK. I've had busted inputs on mine. Wire pin 15 to ground.
 
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Looks like your wiring is fine, at least for the shifter board and the Model 3 filter board.

Are you sure your shifter board is working? I have two Sega Rally uprights and one of mine was broken. Had to replace two of the ICs on it.

Double check that the filter board is OK. I've had busted inputs on mine. Wire pin 15 to ground.
Yeah, my wiring seemed all good, however I noticed some questionable traces on the back of the PCB too. Ran a wire to the faded 5V trace and no go. The gears still stay in position & move 3 pins when just connecting the GND, so something must be wonky. Tested on my actual Sega Rally M2A board and it doesn't work there either. I did sent this one off for repairs and one of my modded wheels with a simple DB15 breakout.

I had spoke to Ken (irepairsega) about the little logic board and he told me that at Sega when they were making upright Daytona, they actually used a similar PCB inside for a 4-switch gear shifter (like the US JAMMA drivers such as Cruis'n) that emulates the inputs of the 3 switches and joystick combinations. He's actually looking forward to checking it out. :) Fingers crossed.

On my main DB15 breakout I even made me a cable to use either the 3-switch shifter or logic board, or connect directly to the filterboard for sequential games, using 2-pin and 3-pin JST SM connectors. For 5V and GND I just use Dupont connectors, but high quality ones make a huge difference from cheap ones.
 

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I didn't check. But I know when I moved the pins around, it would basically go from (in Scud Race) View 4, Shift 3, and Shift 4. Do you mean plugging the pins of 13 and 15 to the actual OUTPUT connector? I was always hesitant of doing something like that to avoid a possible short circuit.
Have a feeling a chip is probably bad too.
The shifter board is out for repairs so it isn't in my possession atm.
 

nem

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That's because Shift 1 and Shift 2 are a combination of inputs. Shift 1 for instance is 1P DOWN and 1P RIGHT.

Take a piece of wire with dupont connectors on the ends. One end of wire goes to pin 13 and the other to any one of the grounds that are on the filter board (like pins 6-11 on CN12). Do this with pin 15 also.

https://www.arcade-projects.com/threads/sega-model-2-and-model-3-filter-board-pinouts.1121/

This is how you make sure your filter board is OK. You don't need the shifter board for this.
 

waiji

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ep1339_repro_board.jpg


Made a repro board. It may work? Unfortunately, I just had a whole bunch of PCBs made in China, so it will be a while before I get to test it myself.

Parts list:

Code:
H1        2.54mm 10-pin header
D1-D8    1N4148 signal diode
R1-R2    1K resistor
R3-R6    10K resistor
C1-C2    0.47uF cap
U1        74HC14
U2        74HC193
U3        74HC03

1649262478907.jpg




Works really well! Thanks a lot nem!!
 
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