nfg.forums

NFG Forums => Controllers and Joysticks => Controller Technic => Topic started by: Pepper on May 06, 2012, 06:20:32 AM

Title: SNES/SFC Controller PAL-compatibility resistor-values (and locations?)
Post by: Pepper on May 06, 2012, 06:20:32 AM
Hi,

That again?! >:(
I know..

But! ;D
I haven't found anything about this specific "problem". :o

I built clumsily threw together an adapter to use Neo Geo (well, something similiar to the Super NEO GEO Controller Pinout (http://gamesx.com/controldata%2Fsuperneo.htm)) on an SNES/SFC a few days ago, and today i wanted to make it compatible with my PAL SNES. When i opened up two third party controllers, which are PAL-compatible, i found they didn't use a 1.2kΩ and a 3kΩ resistor, but two 1kΩ (brown, black, red, gold) resistors connecting P/S (Latch) and Clock to Vcc +5Volt, if i remember correctly.
I adapted my adapter ( :D ) the same way and it works.

So my questions are:

Thank you!

edit: Thanks to micro! I meant 1 kilo Ω, not just 1 Ω.
Title: Re: SNES/SFC Controller PAL-compatibility resistor-values (and locations?)
Post by: micro on May 06, 2012, 07:25:53 PM
Using 1 Ohm as pullup resistor is not safe by any means. But I guess (or hope) you got the color rings wrong. Brown-black-red-gold should result in an 1 kOhm resistor.

If I were you I'd use a 10 kOhm resistor, that's just the most common value for a normal pullup resistor. If the resistor is lower then the line gets pulled up faster, but there's also more current through the resistor. Lower resistor -> pull-up slower but also lower current & power consumption.
Title: Re: SNES/SFC Controller PAL-compatibility resistor-values (and locations?)
Post by: Pepper on May 06, 2012, 09:47:14 PM
What i got wrong was the Ω-value in my first post. Phew!

I used 10 kΩ as pullups for the buttons, like in the wiki (http://www.gamesx.com/wiki/doku.php?id=controls:nes_snes_controller).
The resistors i found in the third-party controllers, and those i used myself are 1 kΩ (brown, black, red, gold), the missing k was an unfortunate typo.

So do i just need some kind of pullup for a PAL SNES to talk to my controller? The exact value doesn't seem to matter much?
So i guess i'm on the safe (if not very power-efficient?) side with 1 kilo Ω.
Title: Re: SNES/SFC Controller PAL-compatibility resistor-values (and locations?)
Post by: micro on May 06, 2012, 11:17:48 PM
Just a typo, good :D

1 kOhm pullup resistors probably won't damage your SNES but I'd still use 10 kOhm resistors instead.
Title: Re: SNES/SFC Controller PAL-compatibility resistor-values (and locations?)
Post by: Pepper on May 06, 2012, 11:35:48 PM
I might replace them.. some day  :)

Would you also recommend replacing the resistors inside the third-party controllers?
Title: Re: SNES/SFC Controller PAL-compatibility resistor-values (and locations?)
Post by: micro on May 08, 2012, 04:17:45 AM
Hmm, I guess I wouldn't replace them, but if I'm about to make new circuit be myself I'd definitely use the 10 kOhm resistors.