Atari 2600+ Cartridge teardown

[xinetic]

I haven't actually found a teardown of the cartridge yet, so here's a mini teardown.

You can easily remove the sticker with hot air.

And then the cartridge is secured with 2 screws and clicked in 4 places.

 

Unfortunately I haven't had time to make a trace route yet, but I was just very curious about what was inside.

But quickly speaking, this cartridge does not seem to be pin-compatible with the pinout of the 2600/7800 cartridge socket, so I think somehow the 2600+ detects whether there is an original 2600/7800 cartridge in it or whether there is a 2600 + cartridge is in it.

 

I have the impression that the 2600+ cartridge can be read, but it seems impossible to program it without opening the cartridge because the WE# is connected to VCC (high)

 

(google translate)

[Spanner]

It looks like a nand type IC with ram...

https://pdf1.alldatasheet.com/datasheet-pdf/view/105428/EON/EN29LV512.html

https://www.ti.com/product/SN74LS04

[+karri]

It is not 5V compliant. So it probably won't work on a real 2600 or 7800. It is a 64k rom only. With no bankswitching. So my guess is 16 games, 4k each. So there is a few unused banks also.

[fluxit]

1 hour ago, karri said:

It is not 5V compliant. So it probably won't work on a real 2600 or 7800. It is a 64k rom only. With no bankswitching. So my guess is 16 games, 4k each. So there is a few unused banks also.

That's what the resistor networks and vreg are for.

[+karri]

5 hours ago, fluxit said:

That's what the resistor networks and vreg are for.

The chips nominal voltage is 3V with an absolute maximum of 3.6V. The TTL "high" data has to be from 2 - 5V. So without active buffers I have a feeling that we are very close to the cart not working. Especially if the cart connector adds any resistance.

 

From the pictures the edge connector looks like it does not have a gold coating. It is just the plain pcb.

[boggis the cat]

On 12/5/2023 at 11:16 PM, karri said:

The chips nominal voltage is 3V with an absolute maximum of 3.6V. The TTL "high" data has to be from 2 - 5V. So without active buffers I have a feeling that we are very close to the cart not working.

The 4-in-1 that comes with the paddle controllers works fine on older ‘Vader’ age 2600s - both PAL and NTSC.

U3 looks like a voltage regulator, and appears to be driving the 74x logic.

[+karri]

The databus is connected directly to the console while the address bus goes through resistors.

 

It is nice to hear that the cart works on a real 2600!

[Blinky]

On 12/4/2023 at 7:21 PM, xinetic said:

I haven't actually found a teardown of the cartridge yet

I did a tear down of Mr. Run and Jump here but it's great to see the internals of the 4-in-1 cart 👍 I'm surprised to see they added an actual 74LS04 and not one of the modern single gate chips. I guess it was cheaper.

 

On 12/4/2023 at 7:21 PM, xinetic said:

it seems impossible to program it without opening the cartridge because the WE# is connected to VCC (high)

Yes but WE# is not connected to VCC but pulled up to VCC with resistor R1 so it's possible to reprogram the chip without desoldering it or lifting the WE# pin.

 

On 12/5/2023 at 3:53 AM, karri said:

It is not 5V compliant. So it probably won't work on a real 2600

3.3V can interface with TTL but on noisy systems a cart may not work as reliably.

 

[Blinky]

On 12/5/2023 at 11:16 AM, karri said:

From the pictures the edge connector looks like it does not have a gold coating. It is just the plain pcb.

Th finish is called HASL and it's cheaper than the gold looking ENIG finish.

[+karri]

8 minutes ago, Blinky said:

Th finish is called HASL and it's cheaper than the gold looking ENIG finish.

But HASL should be coloured like solder. In the photo it looks like the edge connector is not finished by anything. If it is not covered by anything then the acids found on your fingerprint will start corrosion on the copper. So just to be sure I would not touch the edge connector.

[Blinky]

3 minutes ago, karri said:

HASL should be coloured like solder

That's what it looks to me in the images. Solder(silver) color.

[+karri]

1 minute ago, Blinky said:

That's what it looks to me in the images. Solder(silver) color.

In that case it is ok. For me the silver on the vias looked like solder while the edge connector looked like copper. But it is hard for me to see because of the reflections.