Sega Controllers on a Commodore 64

[dvdguy]

Can you use Sega Master System and Genesis controllers on a C-64 without any modifications?

[ApolloBoy]

Yes you can, except only the D-Pad and Button B (Button 1 on an SMS controller) will work. However, Button B/1 acts as the fire button.

[Garak]

Not really a good idea unless you modify them first. The Sega pads (and even more specific the Genesis pads) aren't wired the same as your standard Atari/C64 joysticks - and you _can_ damage the CIA chip which handles joystick/keyboard handling with one. The damage most likely may occur when you press a keyboard key (ie to use a menu item or such) at the same time you press any directional/fire button on the pad. The result is a "tug-of-war" of the I/O lines between the CIA chip and the Sega pad and can fry the CIA chip.

 

The more specific technical reason and fix (requires some diodes) can be found here at the "Commodore Knowledge Base" http://www.floodgap.com/retrobits/ckb/ and look up article number 26 (use the "Enter an article number" link).

 

Garak

[tyranthraxus]

I used a SMS joystick for years in the late 80s and no problems. Its

very rare that you will ever have to move the joystick and press a

key.

[Garak]

I used a SMS joystick for years in the late 80s and no problems. Its

very rare that you will ever have to move the joystick and press a

key.

 

Not that rare. For example many games use the space bar as a second weapon or to switch a weapon. So if you have the fire button held down firing a weapon or holding a direction down while hitting the space bar for a secondary weapon or to bring up an item menu - this is when the CIA can be damaged.

 

With the chips in C64 no longer being made and are getting harder to find (and certainly will be) I believe it's better not to risk the chance of damage.

 

Garak

[Rockin' Kat]

I had one of the CIA chips in my C64 croak on me.... I had previously used Genesis ASCIIware joystick before I knew it was bad for the C64.... though I didn't have the stick attached at the time of CIA death.

 

Anway, I had explained the symptoms in a C64 mailing list and had the problem narrowed down to one of the CIA chips... I then bought a used chip from another member on the mailing list and had my C64 up and running again shortly.....

 

Anyway, I really don't recomend you use Genesis pads or joysticks on a C64 or C128.

 

On the other hand, SMS pads and joysticks should be perfectly ok.

[tyranthraxus]

So is this problem specific to Genesis or Master System controllers?

[Garak]

So is this problem specific to Genesis or Master System controllers?

 

Well, it seems that the above Commodore Knowledge Base article (written by one of the designers of the C64/C128's "SuperCPU" at CMD) seems to generally indicate any Sega game pad: Genesis or Master System.

 

Garak