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

[KCgamester]

I'm still having very little success with dumping my 7800 carts.. I have hardware version 5 with RTC, Clock Generator, firmware V15.4, and Vselect. Roughly 90% of my 7800 games will not dump properly. Any advice would be appreciated.

[bootsector]

I'm still having very little success with dumping my 7800 carts.. I have hardware version 5 with RTC, Clock Generator, firmware V15.4, and Vselect. Roughly 90% of my 7800 games will not dump properly. Any advice would be appreciated.

I'm also having issues dumping Atari 7800 cartridges. I have the same version dumper. I have v1 of the 7800 cart adapter. I ordered version 2 of the 7800 cart adapter from eBay. I'm hoping that will make a difference. A.R.T.I. is listed in the A7800 dump list, but I can't get a good dump.

Update: I was able to dump a working copy of A.R.T.I. After I set the header I was able to load and run on my MiSTer FPGA.

7800 A78 Header Info : atari.a78

embedded game name : A.R.T.I
rom size           : 262144
cart format        : SuperGame ram@4000
controllers        : 7800joy1 7800joy2
save peripheral    : none
xm/xboard          : not enabled
tv format          : NTSC

Did you remove the clock generator from your OSCR or did you just disable it in Config.h?

[NML32]

I didn't remove the clock generator or disable it in the config after I dumped A.R.T.I. I used 7800header.exe to set the header to SuperGame ram@4000. Then I could load the game on my MiSTer FPGA.
These are the settings I'm using.

[bootsector]

That's interesting. Are you able to get the same ROM contents dump (hash verified) three times in a row? From looking at the current code, the clockgen will interfere with PH1 and getting a good dump would be just luck?

[NML32]

I dumped 4 times and got the same hash CRC32 ebe905a1
I didn't build my OSCR. I checked with the person who built it to verify that it has a clockgen module.

[bootsector]

Thanks! Just figured out that not all games use the bank-switching mechanism that uses the clockgen, so for those games they should dump just fine.

[bootsector]

Waiting for a couple of new released Atari 7800 games to arrive. Got myself a v2 Atari 7800 adapter. What should I do in order to make the dumping process more reliable while I wait? Would disabling CLOCKGEN and RTC in Config.h help?

[bootsector]

Taking a look at the code here, I'm wondering why is RTC affecting the 7800 functionality at all? I see references in the code to the CLOCKGEN but not RTC.

[bootsector]

Just opened a PR that might help with this: #1150

[smesgr9000]

yes sorry the Clockgen not the RTC is the issue. I was distracted writing the post. Your PR will likely not helping. If I recall correctly the Clockgen pulls the PIN either low or high if disabled. Thus the Ardurino still can't control the PIN. My Workaround was to instead pull the PIN itself use the Clockgen to move into a constant high or low state. But this isn't really good coding standard. I was thinking on disabling the clockgen in high impedance state and than use the non-clockgen code. But for some reason this didn't work. But I haven't had enough time yet to figure out whats going on, maybe just a silly bug.

[bootsector]

Oh, so we need to physically remove the clock gen from the OSCR? Yep, my PR won’t work for sure then.

[bootsector]

@smesgr9000 thanks for your insights. I've updated my PR with the code that should put the clock gen in HI-Z mode if disabled. This is fully NOT tested yet though as I'm still waiting for my carts to arrive.

[bootsector]

Stupid question: do we need a clock generator for dumping any 7800 game at all?

[KCgamester]

For the record, disabling the RTC or physically removing the battery does not work.

[bootsector]

Yep. The issue is not related to the RTC but the clock generator

[bootsector]

@KCgamester @cmcm711 just in case you (or anyone else having a HW5 with a clock generator) want to give my PR a try, just download the current release zip package and update the files from the zip attached to this post before configuring/building/flashing.

Please make sure your config has ENABLE_CLOCKGEN enabled.

Test reports are hugely appreciated. Thanks!
PR.zip

[sanni]

Try this 7800.zip

It mimics how HW3 with "CLK1 switch set to off" does bank switching but uses the clkgen: clk pin is set high by default and only pulses a couple of times during bank switching.

Top HW5, bottom HW3:

I set the clk to 10 kHz to get 9 pulses similar to the 8 on HW3.

[NML32]

Yes, my Tiger-Heli dump before the header applied.
MD5: 5d9ac066e685432825d968f166b042ec
SHA1: 7f96ba3e9e497bd220098146dedbe8f1a3c250f8
SHA 256: acc64ed224e026e271c26fd7b734dd3f642ab951516f2b7972c622483d475544

[bootsector]

@NML32 the scores from your screenshot look crazy high. I can't reproduce the issue here. It allows me to put my initials just fine and I see no graphical glitches.

This is what I get on the Atari7800 (24.04.23) MiSTer core:

This is the header info according to 7800header version 0.21 Aug 10 2023 13:57:54:

[NML32]

@bootsector Thank you for testing. I found the issue. If I have Save Key enabled, I have the high-score issue.
Under Atari 7800 settings
Peripherals > Port2 Input: SaveKey
I set it back to Auto, and all is good.
Weird.

[KCgamester]

Update!

1. I've discovered that my cart reader (Aliexpress) has a small gap in the SNES port, making the connection unrealiable. I have to ensure that the 7800 adapter is adjusted furthest to the left in order to dump properly.
2. All my carts with no mapper now work in both the Mister FPGA and the 7800 Game Drive, with the exception of Pole Position II. I was able to get Ballblazer's pokey to work by entering pokey@4000 in the header.
3. By using the header info provided by @bootsector and the .ino file provided by @sanni , Bently Bear's Crystal Quest and Tiger Heli both now work in Mister FPGA and the 7800 Game Drive.

Thanks!!!

[bootsector]

Another report about Pole Position II not dumping correctly! That's very weird! Looking forward to my cart to arrive from eBay so I can take a look at it myself.

[bootsector]

@sanni wondering if the additional 1 pulse would affect anything? For functionality parity and peace of mind, would it be possible to slow down the frequency of the clockgen a little bit aiming for 8 pulses in that interval?

[PW5190]

I'm considering on getting a 7800 adapter to dump new cartridges produced by Atari. I'm thinking of getting two from Atari directly: Mr. Run and Jump 2600 and Pac-Man Double Feature 7800.

[bootsector]

Had no issues dumping Pole Position II, although we do have two reports here from people not being able to dump it:

Wondering what could be causing issues to some people as this game doesn't use bank-switching at all. 🤔

[KCgamester]

I was able to dump Pole Position II using adapter v 0.1, but not on v 0.2. Weird.

[bootsector]

Pretty sure this is something physical related to the connector and the cartridge and not software/firmware related.

[KCgamester]

Agreed.