CPU to Cartridge Pinout for 2600

[rallyrabbit]

I am trying ti find a proper pinout for the cartirdge on both the cartridge and CPU side for the 2600. I have found a few schematics that seem to be almost compatible but not quite.

 

For the connector, I chose these two because of their compatibility to the 2600:

https://www.digikey.com/product-detail/en/sullins-connector-solutions/EBC12DRTH/S9669-ND/1317713

https://www.digikey.com/product-detail/en/sullins-connector-solutions/EBC12DCWN/S3304-ND/927256

 

They'll take a bit of mechanical work to pull off. So the dilemma is that I have found a few schematics that look ok, the best case seems to be this:

 

So overall this looks pretty good, except that the connectors I have lay out ping 1-24 differently, which makes me question the layout of the original connector.

 

The sullins connector I have looking at it from the bottom is:

1 3 5 7 9 11 13 15 17 19 21 23

2 4 6 8 10 12 14 16 18 20 22 24

 

I am kind hoping to get an idea of what's what before I power this thing up.

[rallyrabbit]

Let me add some more to this.

 

The sullins connector I have looking at it from the bottom is:

1 3 5 7 9 11 13 15 17 19 21 23

2 4 6 8 10 12 14 16 18 20 22 24

 

Looking at the bottom of a C015519 Rev 14 from a darth vadar units (NTSC) (see attachment). So if I look at this lined up with the sullins connector, it looks like:

23 = ground

21 = diode to Vcc

2 = diode to ground

 

Essentially this means that the atari lines up supposed pins to the board layout would be:

13 14 15 16 17 18 19 20 21 22 23 24

1 2 3 4 5 6 7 8 9 10 11 12

 

Doe anyone know if that is accurate?

[ChildOfCv]

By the orientation of your picture, the bottom is the 1-12 pins and the top is the 13-24 pins. You can tell because 12, 23, and 24 are wide traces, and 24 goes straight to the ground rail. When looking at the top of the board, flipped horizontally, left to right is 1-12 and 24-13.

I'm not sure why you care about the order of the pins as called out on the connector though. Each pin connects directly to the PCB hole below it. So on the connector you could label them with whatever numbers, letters, names, etc that you want. Well, you number them to match the pin assignments on the board you're connecting it to.

 

On Colecovision they do the counterclockwise numbering on the expansion slot, but do the across numbering on the cartridge slot. At least Atari only has one convention to worry about.

[ChildOfCv]

Also, those are wire coil chokes, not diodes.

[rallyrabbit]

You're right, they are coils.

 

Because I am trying to wire up something to read cartridges directly and none of the 24 pin female connectors had a numbering scheme that seemed remotely close to the way Atari laid it our on their schematics

[ChildOfCv]

Okay. Well, Atari's signals are numbered as if it were the counterclockwise pin assignment, so pretend the card edge connector uses the same thing.

[rallyrabbit]

So, roughly that means that this schematic:

 

 

That lines up with the below (upside down view of the board):

 

 

So that would mean top left to top right (schematic to numbering looking at the bottom of the board)

 

13 14 15 16 17 18 19 20 21 22 23 24

12 11 10 9 8 7 6 5 4 3 2 1

 

IF true, I haven't seen anyone number pins on a connector like that before and my company has products that go back 30 years.

 

 

[ChildOfCv]

Well, the schematic lines up with the picture.

 

If you're going to doubt what some random person on the Internet tells you anyway, then the next logical step is to grab the ohm meter and check it yourself.

[rallyrabbit]

You're right, after I posted I was tallying the lines on some of the other chips top side rather than bottom and realized the alignment is all just like on the schematic. So thank you for the help