Some Atari 7800 carts dump fine with hw3, not with hw5

[PsyK0p4T]

Hey people,

Creating this thread to share some behaviors I had here.
I've got two kits here, one hw3 and a hw5. None of them were built by me, so won't be able to precisely discuss about the components used in both. Just never had any particular issues with them until now, and I've dumped a large quantity of games/systems.

My issue came with Atari 7800. I'm using the A7800 to SNES adapter.
Carts for this system come in different capacities.
Smallest ones (Donkey Kong Junior, Super Huey...) are 48KB, and can be dumped fine on hw3 AND hw5.
Higher ones, like 128KB (Commando, Ace of Aces...) recquire bank switching. For these ones, only my hw3 managed to dump them fine. The hw5 seems to not bank-switch properly.

With these results, the code seems out of cause, as the SNES slot and A7800 adapter.
So the problem would be more coming from the reader itself, hardware side ?
Could the voltage be the problem here ? Is the hw3 known to deliver a bit more than hw5 in general ?
I don't have big equipment like an oscilloscope here. But if there are some tests I can do on the SNES slot, with a voltmeter for example, just tell me. Maybe old systems/chips are more greedy and ask for more power to run properly. Any of you ever encoutered this ?

[sanni]

On HW3 the SNES slot's CPU CLOCK pin can be connected to either the Adafruit Clock Generator or the Atmega2560's PH1 pin by the CLK1 switch.
HW5 behaves like a HW3 with the two CLK switches constantly set to the ON position (=connected to clock generator).
With the switches set like this your HW3 should also fail to dump Atari 7800 cartridges that need a bank switch.
The reason being that the bankSwitch_7800() function uses the PH1 pin.
This means the code and the 7800 adapter PCB need to be updated to work on HW5.

[PsyK0p4T]

Thanks for your feedback sanni !
Unfortunately, I won't be able to test your point for the moment. I had borrowed these carts from a friend, and had to return them. I'll try to buy some for future uses.

[sanni]

It could also be possible to leave the adapter PCB as is and try to use the Clock Generator in the bankSwitch_7800() function. Possibly the preferred way.
I think we had something like this before with some other system and there using the Clock Generator instead of PH1 did indeed work.

[smesgr9000]

thanks for the hint @PsyK0p4T . I will try to investigate further.

[smesgr9000]

I got the following games working with this and the dump is identical to the Atari Max:
Supergames:
Crack'ed
Mat Mania Challenge
Motor Psycho
Scrapyard Dog

Normal:
Ballblazer
Donkey Kong

PATCH.txt

[smesgr9000]

@PsyK0p4T do you have a chance to test the above patch?

[PsyK0p4T]

Hey,
Unfortunately, not yet. I don't have the cartridges in hands at the moment, and must borrow them back from a friend. I hope to get them soon...
Can you maybe post the full 7800.ino file with your updates already merged in ? It will be faster ;)

[smesgr9000]

Hey
sure, but be aware if other stuff changes the file may not be compatible anymore. You have to rename it back to ino due to github doesn't allow ino file endings.
7800.txt

[PsyK0p4T]

Good news here !
I had the time to get back some cartridges and test your code. It's working perfectly ! With previously supported games, and also the ones which had timing problems. Thanks for this contribution, it will be merged soon :)

Tested and working : Crack'ed, Ikari Warriors, Donkey Kong Junior, Super Huey, Commando, Ace of aces.

[smesgr9000]

nice thanks