Sega Megadrive official 6 Button Pad on CD32/A1200?!? - Page 3

robinsonb5 · 06 September 2017, 01:35

Quote:

Originally Posted by Akira

Have you done any changes since the version I have, mate? Should I update the software on the prototype board?

I think the version you have is the latest one, but I couldn't swear to it now. I know I changed the button mapping after your initial feedback, but I think I sent you an updated version with that change?

Amiga1992 · 06 September 2017, 02:08

Yeah we went back and forth with changes, now I don't remember if I ever managed to flash it, I think I did! I will have to check again.

Higgy · 23 May 2018, 10:17

I got one built and just about fitted it into the smallest case I could find!

Thanks to robinsonb5 for the help in answering some questions.

robinsonb5 · 23 May 2018, 11:46

Quote:

Originally Posted by Higgy

I got one built and just about fitted it into the smallest case I could find!

That's looking very tidy - nice work!

Higgy · 23 May 2018, 13:09

It was a tight squeeze! The file had to be brought out

Question - (sorry if I am not explaining this correctly) does the PSOC produce 3.3v signals on the AMIGA side? As I would like to know if I can plug it into my FleaOhm FPGA running MiniMig. The Flea creator told me I can't use an AMIGA mouse because it uses 5v signals and the Flea is only 3.3v tolerant.
I assume the chip in the Sega pad produces 5v signals.
Thanks

Valken · 23 May 2018, 16:35

Really good work... Wondering if there is a USB adapter for these controllers? Would be fantastic on the PC and WinUAE.

I'm still on my PS2 to USB controllers for the PC.

Sephnroth · 23 May 2018, 19:33

This looks the bomb diggy. I might have to build one.

Amiga1992 · 23 May 2018, 19:46

It is a great project indeed, I'm really happy with my adapter! Hopefully more people get into this train because Sega 6B pads are the best things in the world. The official ones, though, don't bother with anything else.

robinsonb5 · 24 May 2018, 00:41

Quote:

Originally Posted by Higgy

Question - (sorry if I am not explaining this correctly) does the PSOC produce 3.3v signals on the AMIGA side? As I would like to know if I can plug it into my FleaOhm FPGA running MiniMig. The Flea creator told me I can't use an AMIGA mouse because it uses 5v signals and the Flea is only 3.3v tolerant.

I will have to double-check by loading the project in PSOC creator and checking the pin settings, but I *think* the outputs are all set so that the pin is left high-impedance for the high state, and not driven to either 3v3 or 5v. If so, then it'll be fine. I'll double-check.

EDIT: It turns out I was thinking of the older PIC-based version of the adapter, which never worked very well. The PSOC version currently has "resistive pullups" enabled on all pins - except pin 9 which is set to "strong drive". Which means that all pins will present 5v in the high state - so you can't currently connect it to the Flea.
Setting all pins to "Open Drain, drives low" will prevent that from happening, but I suspect Pin 9 will no longer switch quickly enough to transmit the CD32 button states if you do that.

If I can dig out (since my move a couple of years ago) my Sega pads and remaining adapter I will try it out when I get a chance - but if you want to try it yourself, look at the TopDesign schematic view, double-click each group of pins surrounding the CD32Shifter and set the pin mode on the General tab.

Also note, as far as I know (I'd love to be proved wrong here!) the Flea Minimig core currently only has pin mappings for two of the three fire button lines, and (probably) only supports input mode on those two pins - so the core will need some extra work to support CD32 pads.

gjb1985 · 31 October 2019, 11:21

does a megadrive controller work without modding it? Either the regular one, of the 6 button one? It doesn't frie or break any ports?

Shatterhand · 31 October 2019, 12:20

Quote:

Originally Posted by gjb1985

does a megadrive controller work without modding it? Either the regular one, of the 6 button one? It doesn't frie or break any ports?

It works, but with just 1 button (B). For games using a 2nd button, (C) sometimes will work, sometimes it won't ,depends on how the game was programmed.

Some people will say there's some risk on using it, some people will say its safe, people have been using Mega-Drive pads on Amiga for decades now and there was never a report of it frying anything.

Gordon · 31 October 2019, 12:24

It does use a different pin to draw power from than a normal one button controller but it is fine. Some Amiga designed peripherals user it too. If you have a cd32 I would recommend getting an adapter so you can use all the buttons on a 6 button MD pad.

robinsonb5 · 31 October 2019, 12:44

Quote:

Originally Posted by gjb1985

does a megadrive controller work without modding it? Either the regular one, of the 6 button one? It doesn't frie or break any ports?

There's definitely a problem using them with a C64, but they shouldn't pose any risk to an Amiga.

Daedalus · 31 October 2019, 15:12

The only risk to the Amiga is if the game continuously tries to read it as a CD32 pad, which can lead to contention situations where the logic in the controller fights the logic in the Amiga. The vast majority of the time it's perfectly safe. However, as said, it draws power from one of Paula's ADC pins rather than the Amiga's 5V supply, which isn't the right way to go about things. It also means that the pin needs to be in the correct state for the pad to work - some Kickstart & game combinations don't do this, meaning the pad won't work. A simple adaptor can get around this though by powering the pad correctly and locking it in 2-button mode, and adding a few diodes to the adaptor will also make it safe for use on a C64.

idrougge · 31 October 2019, 23:58

How does one lock it in 2-button mode?

lord of time · 01 November 2019, 09:39

I dont know if this is of any help to anyone but Amstrad CPC PLUS controllers work a treat with a simple wire swap!

Daedalus · 01 November 2019, 09:46

Quote:

Originally Posted by idrougge

How does one lock it in 2-button mode?

When pin 7 is high, the MD pad configuration will coincide with the 2-button Amiga operation setup. That's why it mostly works on the Amiga, since pin 7 is the 5V power line. What I do though is connect pins 7 & 5 of the MD pad with a 1K resistor, and connect pin 5 of the MD pad to pin 7 of the Amiga. This ensures it has the correct power supply and also remains in 2-button mode.

Quote:

Originally Posted by lord of time

I dont know if this is of any help to anyone but Amstrad CPC PLUS controllers work a treat with a simple wire swap!

And Sega Mastersystem controllers work as a 2-button controller without any modification.

Shatterhand · 01 November 2019, 14:34

You can build your own 2 button controller very easily. There's no circuit, you just need to wire buttons and directions to the DB9 connector.

Jami · 20 December 2021, 18:11

Quote:

Originally Posted by Daedalus

When pin 7 is high, the MD pad configuration will coincide with the 2-button Amiga operation setup. That's why it mostly works on the Amiga, since pin 7 is the 5V power line. What I do though is connect pins 7 & 5 of the MD pad with a 1K resistor, and connect pin 5 of the MD pad to pin 7 of the Amiga. This ensures it has the correct power supply and also remains in 2-button mode.

@Daedalus : I'd like to mod my megadrive controller following your advice (6 buttons pad -- the blue one licensed by Retro-bit). I have been using it on my Amiga 500.

Click image for larger version

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I am wondering what kind of 1 KOhm resistor to buy.

What power for this resistance? 3W, 1W, 1/4W... ?
And what precision? 10%, 5% or less ?

Daedalus · 27 December 2021, 21:57

Neither the power not the precision are critical - even the value isn't that critical. 0.25W, 5% is fairly common and will do just fine.

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06 September 2017, 02:08	#42
Amiga1992 Registered User Join Date: May 2001 Location: ? Posts: 19,645	Yeah we went back and forth with changes, now I don't remember if I ever managed to flash it, I think I did! I will have to check again.

23 May 2018, 10:17	#43
Higgy Registered User Join Date: Jan 2014 Location: Somerset, UK Posts: 547	I got one built and just about fitted it into the smallest case I could find! Thanks to robinsonb5 for the help in answering some questions.

23 May 2018, 13:09	#45
Higgy Registered User Join Date: Jan 2014 Location: Somerset, UK Posts: 547	It was a tight squeeze! The file had to be brought out Question - (sorry if I am not explaining this correctly) does the PSOC produce 3.3v signals on the AMIGA side? As I would like to know if I can plug it into my FleaOhm FPGA running MiniMig. The Flea creator told me I can't use an AMIGA mouse because it uses 5v signals and the Flea is only 3.3v tolerant. I assume the chip in the Sega pad produces 5v signals. Thanks

23 May 2018, 16:35	#46
Valken Registered User Join Date: Feb 2009 Location: Amiga Posts: 465	Really good work... Wondering if there is a USB adapter for these controllers? Would be fantastic on the PC and WinUAE. I'm still on my PS2 to USB controllers for the PC.

23 May 2018, 19:33	#47
Sephnroth Registered User Join Date: Oct 2014 Location: England Posts: 77	This looks the bomb diggy. I might have to build one.

23 May 2018, 19:46	#48
Amiga1992 Registered User Join Date: May 2001 Location: ? Posts: 19,645	It is a great project indeed, I'm really happy with my adapter! Hopefully more people get into this train because Sega 6B pads are the best things in the world. The official ones, though, don't bother with anything else.

31 October 2019, 11:21	#50
gjb1985 Registered User Join Date: Dec 2012 Location: netherlands Posts: 109	does a megadrive controller work without modding it? Either the regular one, of the 6 button one? It doesn't frie or break any ports?

31 October 2019, 12:24	#52
Gordon Settler Join Date: Feb 2007 Location: Serf City Posts: 1,760	It does use a different pin to draw power from than a normal one button controller but it is fine. Some Amiga designed peripherals user it too. If you have a cd32 I would recommend getting an adapter so you can use all the buttons on a 6 button MD pad.

31 October 2019, 15:12	#54
Daedalus Registered User Join Date: Jun 2009 Location: Dublin, then Glasgow Posts: 6,334	The only risk to the Amiga is if the game continuously tries to read it as a CD32 pad, which can lead to contention situations where the logic in the controller fights the logic in the Amiga. The vast majority of the time it's perfectly safe. However, as said, it draws power from one of Paula's ADC pins rather than the Amiga's 5V supply, which isn't the right way to go about things. It also means that the pin needs to be in the correct state for the pad to work - some Kickstart & game combinations don't do this, meaning the pad won't work. A simple adaptor can get around this though by powering the pad correctly and locking it in 2-button mode, and adding a few diodes to the adaptor will also make it safe for use on a C64.

31 October 2019, 23:58	#55
idrougge Registered User Join Date: Sep 2007 Location: Stockholm Posts: 4,332	How does one lock it in 2-button mode?

01 November 2019, 09:39	#56
lord of time Banned Join Date: Mar 2016 Location: wolverhampton Posts: 153	I dont know if this is of any help to anyone but Amstrad CPC PLUS controllers work a treat with a simple wire swap!

01 November 2019, 14:34	#58
Shatterhand Warhasneverbeensomuchfun Join Date: Jun 2001 Location: Rio de Janeiro / Brazil Age: 41 Posts: 3,450	You can build your own 2 button controller very easily. There's no circuit, you just need to wire buttons and directions to the DB9 connector.

27 December 2021, 21:57	#60
Daedalus Registered User Join Date: Jun 2009 Location: Dublin, then Glasgow Posts: 6,334	Neither the power not the precision are critical - even the value isn't that critical. 0.25W, 5% is fairly common and will do just fine.

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