How does a Genesis controller work on an Atari 2600?

[napabar]

I'll admit, I'm a bit of a noob when it comes to how controllers work.

 

Question:  How does a Genesis controller work on an Atari 2600 when the pins don't match up?  On the Atari compatible ports, VCC is pin 7.  On the Genesis, it's pin 5.  Yet, a Genesis controller works just fine on a 2600.  How is this possible with the power on a different pin?

 

I currently have an Atari Flashback 2.  The port are compatible with the old Atari standard.  A Genesis gamepad works just fine with this system (and a real Atari 2600), but 8BitDo's Bluetooth receiver for the Genesis port doesn't power up in the Flashback.  No LED light comes on.  I assume this is because the VCC is in a different pin than it's expecting, but then why does the Genesis controller work?  Doesn't it need power too?

 

Again, I'm a noob on this.  Go easy on me.  

 

 

 

 

Edited March 2, 2021 by napabar

[R.Cade]

Because applying +5v to pin 7 (select) on a Genesis controller still is enough to "power" it, backwards through the 74157. It ends up acting the same as putting VCC on pin 5...

 

 

 

Edited March 2, 2021 by R.Cade

[napabar]

15 minutes ago, R.Cade said:

Because applying +5v to pin 7 (select) on a Genesis controller still is enough to "power" it, backwards through the 74157. It ends up acting the same as putting VCC on pin 5...

 

But not enough to power an accessory like 8Bitdo's Bluetooth receiver for the Genesis port?

 

 

[R.Cade]

6 minutes ago, napabar said:

But not enough to power an accessory like 8Bitdo's Bluetooth receiver for the Genesis port?

I assume it's wired so that the +5v is actually required on pin 5 to power the 8Bitdo... unlike the original Genesis design "flaw".

 

 

Edited March 2, 2021 by R.Cade

[Zap1982]

I have always wondered if a 2600 paddle will work on a Sega Master system.. same plug again but Master System paddle controllers are extremely scarce, probably as only a handful of games used them like Alex Kidd BMX Trials.

[+SpiceWare]

25 minutes ago, Zap1982 said:

I have always wondered if a 2600 paddle will work on a Sega Master system..

 

Never knew SMS had a paddle controller, looks like it was only released in Japan.  Based on the info here the SMS paddle sends a digital position value, so the 2600 paddle would not work:

Quote

The position of the knob on the paddle is converted to a 8 bit digital value and has therefore 256 possible values. The current value is transmitted to the console in two blocks of 4 bits (nibbles). The four wires normally used for the directional pad are used for this (DB9 pin 1 to 4).

 

 

 

[Danjovic]

9 hours ago, Zap1982 said:

Master System paddle controllers are extremely scarce,

There are at least two DIY SMS paddle alternatives:

https://www.raphnet.net/electronique/sms_paddle/index_en.php

 

https://hackaday.io/project/167338-smsx-paddle

[Zap1982]

59 minutes ago, Danjovic said:

There are at least two DIY SMS paddle alternatives:

https://www.raphnet.net/electronique/sms_paddle/index_en.php

 

https://hackaday.io/project/167338-smsx-paddle

Loving the wooden one?

We need more wooden peripherals!