The new Atari cart hardware

[Blinky]

 

I've been curious about what hardware is actually inside these new carts and been searching for information about them.

 

What I found out from the Official PCB renders posted  by @alex_79  and the official blog post is that the Limited Editon carts with LED marquee have a T-shapped PCB and other carts have a normal sized PCB.

 

From the production picture @Mockduck   posted, the carts contains:

 

• 128K flash chip (SST39SF010A)

• room for a RAM chip (probably 8K SRAM)

• Xilinx CPLD (probably XC9536XL)

• voltage regulator (probably AMS1117 3.3V)

• Oscilator (probably 50MHz active Oscilator)

 

 

On the back of the PCB are some configuration jumpers. one to enable or disable the RAM and two more to configure the banswitch mode (probably 4K/8K/16K/32K).  The official documentation says "The multi-mapper replaces five variations of three existing mappers" these variations are most likely:

 

• 4K ROM

• 8K ROM

• 16K ROM

• 16K ROM with RAM

• 32K ROM with RAM

 

 

 

 

Since the RAM jumper is not grouped with the bankswitch jumpers, it wouldn't surprise me if  RAM could also be enabled with 4K and 8K ROMs.

 

 

Other interesing things of the PCB is that there is a JTAG header for programming the CPLD.

 

Pin 12 of the cart, which is normally connected to GND has a special function. It is not connected to GND but connected to R1 and then (most likely) to the CPLD. A reason to do something like this is if the cart is programmed through the cart slot. The resistor R1 is a so called pull down resistor as it is connected to GND. They've probably done this for systems that use this pin as a way to detect a cart.

Oops! Did they make a mistake?

 

While looking at photos and frames of @swlovinist youtube video to see if I could identify the CPLD partnumber I noticed something odd about resistor R1. The text on the SMD resistor reads 104 meaning it is a 100K resistor. This is a very high value for a pull down resistor.

 

Systems using pin 12 as cart detect will have a pull up resistor connected to this pin so a 'low' pin of the cart can be properly detected. The value of that pull up resistor will usually be from somewhere around 10K (external resistor) to 50K (internal pull up of micro controllor pin). So the 100K resistor on the cart is not able to pull the pin low enough to be detected.

 

I think someone accidently made a mistake with the BOM (Bill Of Materials) list and entered 104 for the resistor instead of 102 (for a 1K resistor) as 104 is a common value used for decoupling capacitors (also on the PCB) )

 

I think when resistor R1 is replaced with a 1K resistor (102 text on 805 SMD resistor) the cart will be properly detected on troublesome systems.

 

That's all I found out sofar. If anyone has more info or better pictures. PLease post them here!

I'm looking forward to get some of the new carts and have a look under the hood myself

 

 

 

 

[Thomas Jentzsch]

56 minutes ago, Blinky said:

So the 100K resistor on the cart is not able to pull the pin low enough to be detected.

Does that mean the carts will not work in a classic console? 

[Blinky]

1 minute ago, Thomas Jentzsch said:

Does that mean the carts will not work in a classic console? 

It doens't matter for a classic console. The pin on those is normally grounded and not used as a cart detect. However if you have a system that plays built in games when no cart is inserted then such a system will likely have a problem playing the new carts (unless they changed the resistor value)

 

[Blinky]

Got Mr. Run and Jump with my new 2600+ and teared down the cart to see what's inside.

Interesting to see is that they used a PAL20V8 PLD (Programable Locic Device) for the F6 bankswitch scheme (I dumped the game before tear down)
and used a 64K 3.3V flashchip PM39LV512 of which only 32K can be used (Highest addressline A15 connected to GND).  There's also a 3.3V voltage regulator to supply the flash chip with 3.3V and a bunch of 1K resistor arrays to interface the 3.3V logic (flash chip) to the 5V logic (PLD and cart slot).

Unlike I hoped, the flash is not reprogramable through the cart connector and there are no test pads either to (re)program them through those.

The Write enable pin of the flash chip (to program the chip) is pulled up with a 10K resistor though so with some hackery it could be reprogrammed.
 

 

TaDa!:

Removed from the cart, top side.

Bottom side:

[Bakasama]

I was wondering if new Atari carts shells designs are any different from older Atari carts.

Edited November 19, 2023 by Bakasama

[Thomas Jentzsch]

4 hours ago, Bakasama said:

I was wondering if new Atari carts shells designs are any different from older Atari carts.

Me too. Is there a screw behind the label? Doesn't look like that, right?

[Blinky]

8 hours ago, Bakasama said:

are any different from older Atari carts

Yes they are. biggest difference is that there are two screws holding the cart together instead of one.

 

Label side.

Back side:

The screws are different too: Left from original (dust cover) cart, Right: New cart

 

[Bakasama]

Assuming that Albert can get supply of cart shells from Atari, that might mean new homebrew circuit boards might have designed that fit in the these new shells.

[+groundtrooper]

4 hours ago, Bakasama said:

Assuming that Albert can get supply of cart shells from Atari, that might mean new homebrew circuit boards might have designed that fit in the these new shells.

Al already has his own custom injection molded shells for 2600 and 7800 games. I believe he is occasionally still using donor Atari Inc shells(locking dust-cover) for his melody board releases as the new shells don't hold the PCB's well enough but he is working on a revised shell to remedy this issue.