What's new

ConversusWV

Student
Joined
Feb 18, 2021
Messages
28
Reaction score
11
Location
Spartanburg, SC
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
 
Last edited:

nem

Legendary
Joined
May 29, 2016
Messages
4,307
Reaction score
3,587
Location
Finland
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.
 

ConversusWV

Student
Joined
Feb 18, 2021
Messages
28
Reaction score
11
Location
Spartanburg, SC
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

Legendary
Joined
May 29, 2016
Messages
4,307
Reaction score
3,587
Location
Finland
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.
 
Last edited:

nem

Legendary
Joined
May 29, 2016
Messages
4,307
Reaction score
3,587
Location
Finland
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
 

Attachments

  • ep1339_repro_board.zip
    13.6 KB · Views: 6
Last edited:

nem

Legendary
Joined
May 29, 2016
Messages
4,307
Reaction score
3,587
Location
Finland
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
 
Last edited:

ConversusWV

Student
Joined
Feb 18, 2021
Messages
28
Reaction score
11
Location
Spartanburg, SC
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"?
 
Last edited:

nem

Legendary
Joined
May 29, 2016
Messages
4,307
Reaction score
3,587
Location
Finland
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.
 

ConversusWV

Student
Joined
Feb 18, 2021
Messages
28
Reaction score
11
Location
Spartanburg, SC
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.
 

ConversusWV

Student
Joined
Feb 18, 2021
Messages
28
Reaction score
11
Location
Spartanburg, SC
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.
 

Attachments

  • 20210716_165720.jpg
    20210716_165720.jpg
    95.7 KB · Views: 6
  • 20210716_162651.jpg
    20210716_162651.jpg
    142.7 KB · Views: 8
  • 16266380862304143528527080275875.jpg
    16266380862304143528527080275875.jpg
    118.9 KB · Views: 8
Last edited:
Top