Sega Megadrive official 6 Button Pad on CD32/A1200?!?

[Ebster]

Is it possible to make the official Sega Megadrive 6 Button Pad work like the original CD32-Pads? How do they work when unmodified?

Thanks for your answers!

[Ebster]

I just found this on amiga.org forum..

" Everyone probably knows that Sega Genesis Game pads work on Amigas and that they are available new at some of the game trading stores like GameStop. I've collected maybe a dozen of these. Usually, because Sega is different, only 1 fire button works, but it's still a usable joypad.

Whats new to me is that a very simple modification turns these into fully functional 6-button joypads. It was spelled out several years ago in the docs that come with ADoom, which was just re-released on Aminet. I did this last night. You simply swap the Vdd (+5 volts) and Sel wires inside the controller and connect a 470 ohm resister across these same 2 wires.

Of course, most games won't use all 6 buttons. But, it's nice to make these excellent controllers completely Amiga specific and compliant. Even the rapid fire functions work! These are better than the CD32 joypad. "

Has anyone tried this? It would be nice to get some clearer information..

[Ebster]

FOUND THIS IN THE ADOOM README:

Nick Croft <ncroft@enterprise.net> writes:
I have a SEGA Megadrive and two 6 button controllers, but I don't want to
alter one of the controllers as I still use the Megadrive and I don't feel
confident enough to do it anyway
So, I thought about an adaptor that could go between the controller plug and
the Amiga joystick port that swapped lines 5 & 7 and have the required
resistor in it. Would this work, and if it would where could I buy/get made
such an adaptor?

[keropi]

I have tried the swap line thing, didn't work for me, or the info I had was incorrect...
I also have read somewhere that there is a small chip on the cd32 pad that really makes all buttons available, and there was schematics of how to build your own... so after reading that, I just got a honeybee cd32 pad...

[Ebster]

maybe you swapped the wrong lines?? someone on eab said it was supposed to be 5 and 9. the above mentioned are 5 and 7... i will try to build and adaptor soon!

[keropi]

still I think that the PIC will be missing... unless they are compatible...
by swapping lines, the best u get is 2 buttons... but I maybe wrong, do your stuff, and inform us

[Ebster]

i´ll give it a try next weekend and keep you informed. hope that i don´t fry my new cd32...

only two things i still ask myself

1. from which side of which plug (male/female d-sub 9pin) do i count pins 1 to 9?

2. do you think i need one or two resistors, that means pin 5 and 7, pin 5 or pin 7??

maybe someone knows...

[Ebster]

oh my god, it´s getting more and more confusing... another one out of amiga.org:

"The Megadrive (Sega Genesis and Master System) both DEFINITELY work with NO hacks...........but only the joypad and buttons B and C because thats all the Amiga uses.........now, there is a Hack to enhance its use to all 6 buttons for CD32 games. I heard all you have to do is switch pin 9 and pin 6 on the joypad end where the cable ends.

The Spectrum jotpads.I dont think they will work...........the reason I say this is because there is a Joystick made by Cheetah called the BUG, wich has two connectors on it.one for Amiga and one for Spectrum..........which leads me to believe it wont work.otherwise why would they make and end for each on the Joystick.........I think its just a difference in wire config.

I have about 5 Sega Genesis 6 button pads here.which I use for Hired Guns......Dyna Blasters, and other 4 player games on my 4 player adaptor....but I also use them for 2 button games like Turrican 1, 2 and 3 as well as Project X."

[Ebster]

I promise this to be my last spam in this post, but according to this info right here i´ll definately try to swap 5 and 7 and ask my local electronic-equipment-shop for the resistors. makes sense to me!

Greetz, Ebster!

...

Sega Genesis Controller

9 PIN DSUB ??


PinName (Select=GND)Name (Select=+5V)

1UpUp
2DownDown
3Gnd / Left
4Gnd / Right
5+5VDC+5VDC
6Button AButton B
7SelectSelect
8GroundGround
9StartButton C

The chip inside the controller is a 74HC157. This is a high-speed cmos quad 2-line to 1-line multiplexer. The console can with help of the Select-pin choose from two functions on each input.

[redblade]

Hmm there is assembler source code on one of the Amiga Format coverdisks, during the Bull Frog assembler tutorial.

It tells you which wires to swap. Look on nth dimension and look at the pics and try to find one with a sega joypad on it.

Coverdisk 44 I think.

[Dizzy]

dont know if this picture is of any help

[Ebster]

thanx redblade, i found the cover disk and the right doc... they speak about the sega 3 button pad and it says wires 5 and 7 have to be swapped. nothing about resistors. i will give it a try on my 6 button pad as soon as it arrives with and without resistors and keep you informed.

[keropi]

I still insist it won't work... you will only gain a 2nd button with the wire swap.. you need the 74LS165 PIC to sent all those buttons encoded to the amiga so they will be recognised....

[Ebster]

did you swap 5 and 7? did you use the 470ohm resistors? i am still waiting for the two brandnew pads i got from ebay. still cannot try yet...

[keropi]

the resistors and all are components that needed to work WITH the PIC... if the PIC does not encode the buttons and sends them to the amiga, then there is no point really for resistors... resistors do not send data. As I said, the best u could do without the pic is 2 buttons.
I mean, really, thinking of that, if it was so simple as a 2 wire swap, everyone would have done that, and there would be tons of info... don't believe everything they say about cost-free mods that do wonders.

[Ebster]

I still might be proven wrong, but the key seems to be that you don´t only swap the two lines.. it seems that you have to bridge them as well. i read that in a thread about a psx to genesis-pad-adapter thread on amiga.org forum. that is the way they made this special adapter work for the amiga - not for every button as far as i know but i think they got a working two button psx joypad for the amiga using the hacked adapter.

i will

1) swap lines 5 and 7
2) bridge them (don´t know if they have to be swapped in the first place then) with the 470 ohm resistor as mentioned in the following adoomppc docs from aminet:

"
SEGA Genesis Controller
=======================
To use a SEGA Genesis controller, use the -sega3 option for a three
button Genesis controller, and the -sega6 option for a six button
Genesis controller.
The button mapping is as follows:
Start = Space (Action)
A = Strafe Right
B = Fire
C = Strafe Left
On the 6 button controller you also get
Mode = Esc (Menu)
X = Return (Enter/Show last message)
Y = Shift (Fast/Run)
Z = Tab (Map on/off)
A Sega Genesis controller may be use on the Amiga as long
as you swap lines 5 & 7, and put a 470 ohm resistor
between lines 5 & 7.
The controller plug pinout is:
1 2 3 4 5
6 7 8 9
The best way to switch the lines is to open up the
controller and change them on the circuit card.
Note: doing this will make the controller incompatible
with SEGA equipment; if you make the changes, you
are on your own; I will not be held responsible for any
damage incurred by performing the above procedure.
If you aren't comfortable doing your own conversion
and don't know anyone who can help, DON'T TRY IT!
Get yourself a CD32 joypad. This is ONLY for people
who know what they are doing and want the range of
controllers available for SEGA equipment."

3) ...and keep reporting

(@Keropi: i found the thread where you described exactly the same problem - WISH ME LUCK! )

CHEERS, Ebster.

[keropi]

good luck!
I have 2 new genesis 6button pads spare, lol

[chaoticjelly]

I tried the procedure as described on the DOOM faq, swapped lines 5 and 7 at the control pad PCB (I found out which points were 5 and 7 by putting a little bit of wire in the part of the 9 pin socket that corresponded to 5, and then pressing multimeter on end of wire, and then other prong of multimeter on pcb points for data and testing for continuity.. and same for 7.

I swapped the two and bridged them with a 470 ohm resistor.

My CD32 kept resetting when certain buttons was pressed, and kept moving up and down of its own accord..

Conclusion : the mod does not work.. perhaps its only for DOOM on an A1200??? (after all, it is a DOOM faq)

[Jope]

Please be careful when doing those mods, those certain buttons probably shorted +5VDC to ground, thus causing the machine to reboot..

[Ebster]

ok ok ok... you were right - without the modification the sega megadrive 6 button pad did not work at all on my cd32... strange behavior! with the modification mentioned above it works as a 2button pad, like cd32 pad with red and blue button. no problem for games like turrican3 or mortal kombat2 but somehow not for e.g. banshee... i´m a little disappointed but at least it works somehow - button b for red and c for blue...

it was worth the try!!


now back to honey bee