Action Replay 4M Plus Dual Boot Mod

Hey guys here is a simple mod i have done to my Action Replay 4M Plus cartridge so i can dual boot the Action Replay firmware as well as the Pseudo Saturn Kai Lite firmware or a different firmware, For anyone interested here is the guide i've done.

This guide is for Action Replays with 2x 29EE020 eeproms, Board may look slightly different to mine.

Why do i need this?
If you're looking to get Pseudo Saturn Kai or try some other firmware and already own an Action Replay 4M Plus or you have already flashed Pseudo Saturn Kai Lite to your Action Replay 4M Plus then this maybe of interest to you, With this mod you will be able to flash/reflash the Action Replay firmware to your cartridge and then using the switch flash Pseudo Saturn Kai Lite or something else to it as well and then have the ability to switch between the two so you have the benefits of both.

Image:


Link:
Guide As PNG

PDF:
MEGA


If you have any questions please feel free to ask :)
 

Attachments

  • Sega Saturn Action Replay Board Mod Guide.pdf
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For anyone considering performing this mod, please note that @cafe-alpha has recently launched a Patreon campaign to support new versions of Pseudo Saturn Kai, and one of the planned features is backup memory storage for Action Replay cartridges. If this feature gets implemented, this mod won't be necessary for most users.

If you would like to see this (and other cool features) in Pseudo Saturn Kai, please consider pledging your support :)

Patreon page: cafe-alpha is creating a new Pseudo Saturn Kai | Patreon

Additional info: [Reddit] cafe-alpha launches Patreon campaign for new versions of Pseudo Saturn Kai
 
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lol you really have no idea

Care to elaborate? I didn't mean to cause offense as this is a cool mod but, for most users, it won't be necessary when the new firmware comes out. The whole point of this mod is to combine the features of Action Replay stock firmware (save data manager) and Pseudo Saturn Kai (CD-R support). Once PSK has a save data manager of its own, there won't be much need for Action Replay stock firmware unless you want the ability to add/edit cheats.
 
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Care to elaborate? I didn't mean to cause offense as this is a cool mod but, for most users, it won't be necessary when the new firmware comes out. The whole point of this mod is to combine the features of Action Replay stock firmware (save data manager) and Pseudo Saturn Kai (CD-R support). Once PSK has a save data manager of its own, there won't be much need for Action Replay stock firmware unless you want the ability to add/edit cheats.
cafe_alpha has already stated the whole reason he didn't implement save support is because there's a chance it could corrupt PSK and prevent it from working and the only save data manager that is included and will be expanded on is for PSK on something like the Gamer's Cartridge which allows saving to sd card.
also the main reason for this mod is to allow you to keep the action replay firmware in tact whilst still being able to have PSKL on it, as well as being able to use the cheats etc.
 
cafe_alpha has already stated the whole reason he didn't implement save support is because there's a chance it could corrupt PSK and prevent it from working and the only save data manager that is included and will be expanded on is for PSK on something like the Gamer's Cartridge which allows saving to sd card.
I am aware of his stance about that, but @cafe-alpha plans on adding backup memory storage for Action Replay cartridges in Pseudo Saturn Kai Lite, if his Patreon campaign gets enough support. Here is an excerpt from his Patreon:

For several years until now, my goal for Pseudo Saturn Kai was to provide an affordable and non-invasive mod to play Saturn games.
I consider this goal being complete but there are still some "side quests" remaining :

- Add backup memory storage feature for Action Replay cartridges
- Add in-game save data support for Satiator Optical Disc Emulator
- Improve support for Optical Disc Emulators

Patreon page: cafe-alpha is creating a new Pseudo Saturn Kai | Patreon
 
I am aware of his former stance about that, but @cafe-alpha plans on adding backup memory storage for Action Replay cartridges in Pseudo Saturn Kai Lite, if his Patreon campaign gets enough support. Here is an excerpt from his Patreon, which you can find here: cafe-alpha is creating a new Pseudo Saturn Kai | Patreon
that could be a long way off, if he decides to go through with it and it works to a point where he's comfortable releasing it but that could be a long way a way so for you to come here and advertise someone else's thread and patreon is rude at best and you're making out like that feature is coming soon when in reality it may never come you just don't know.
plus this mod isn't just for pseudo saturn kai lite, this mod will let you dual boot any two firmware that will fit on the flash chips.
 
that could be a long way off, if he decides to go through with it and it works to a point where he's comfortable releasing it but that could be a long way a way so for you to come here and advertise someone else's thread and patreon is rude at best...
I'm sorry that you took offense. My intention was to inform people about an alternative option (if the feature eventually gets implemented) for anyone stumbling across this thread, so with that in mind I would say I was being "helpful at best, rude at worst".

...and you're making out like that feature is coming soon when in reality it may never come you just don't know.

In my previous post I said that this feature will come "if his Patreon campaign gets enough support." The key word being "if".

plus this mod isn't just for pseudo saturn kai lite, this mod will let you dual boot any two firmware that will fit on the flash chips.

That's a good point, thanks for clarifying.
 
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cafe-alpha

Established Member
Sorry to pollute this thread with this unrelated post. After this one, there won't be another post from me here.


that could be a long way off, if he decides to go through with it and it works to a point where he's comfortable releasing it but that could be a long way a way so for you to come here and advertise someone else's thread and patreon is rude at best and you're making out like that feature is coming soon when in reality it may never come you just don't know.

Yeah, the "let's make everyone waiting for more than three years to get the thing done and my mortgage being paid" is an extreme nobody want, including me. On the other side, I don't want the "comfortable releasing" being "95% implemented" to be done for free, and the remaining 5% to finally be crowdfunded for 10 bucks.
If you don't like me doing crowdfunding, then that's your opinion. But please stop thinking that open source software is something people are doing for free on their spare time just for the pleasure (and bank account) of hardware resellers.


Oh, BTW, let's take a tour on ebay. There is currently an auction for Action Replay cartridge with Pseudo Saturn Kai v6.324 (latest version) pre-installed. Unit price is USD 60, 7 cartridges are in stock and 74 cartridges are already sold.
Now let's go on play-asia. Price for one Action Replay cart is around USD 30.
Now, quick math time ! 74 * (60 - 30) = USD 2220 gained so far. Not bad for pre-installing a free software that everyone can download from my homepage.


Back to the main subject : if I open a cowdfunding page to get some specific features to be implemented, that's for good reasons :
- I won't implement these features for free ... see above for the reasons why
- I'm confident these features can be implemented in a reasonable amount of time : if I'm not sure about a given project then I usually don't write about it on my homepage or in my blog



cafe_alpha has already stated the whole reason he didn't implement save support is because there's a chance it could corrupt PSK and prevent it from working and the only save data manager that is included and will be expanded on is for PSK on something like the Gamer's Cartridge which allows saving to sd card.

You don't need to detail about Save Data Manager and Gamer's Cartridge details : @privateye knows about them way more than you.

So, I stated that Save Data Manager won't be available in lite firmware, but that was a long ago. After that, I lost time to assemble more Gamer's Cartridge and "all-in-one" carts have their own hardware issues. As a result, there are currently very few solutions to get both Pseudo Saturn exploit, cheat codes and backup memory feature available on a single cartridge.
I still have few time for firmware development, so in exchange of Gamer's Cartridge not being available I would like to provide a similar feature for lite firmware. It won't be as convenient as in Gamer's Cartridge (because of lack of in-game support, and not being able to access SD card etc), but better than nothing.


also the main reason for this mod is to allow you to keep the action replay firmware in tact whilst still being able to have PSKL on it, as well as being able to use the cheats etc.

Of course, let's install Pseudo Saturn Kai on the cartridge. You can even install it twice, which is great ! But let's no forget to claim when its developer begs for a penny.


Last but not least, a forum is a place to share where to share information and everyone's opinion; if you want to unilaterally post something, then an homepage or a blog with comments disabled shall be more convenient.
I'm taking care of Pseudo Saturn Kai official thread, where a lot of people arrive to ask why a game doesn't boots (usually a lens or CD-R problem), or why it doesn't play correctly (because expansion RAM of their cartridge is defective), and I don't kick them because "your post is rude, get out of my thread, bwah bwah !".


End of discussion from me here. Sorry for the trouble caused and I wish you an happy cartridge modding.
 
Sorry to pollute this thread with this unrelated post. After this one, there won't be another post from me here.




Yeah, the "let's make everyone waiting for more than three years to get the thing done and my mortgage being paid" is an extreme nobody want, including me. On the other side, I don't want the "comfortable releasing" being "95% implemented" to be done for free, and the remaining 5% to finally be crowdfunded for 10 bucks.
If you don't like me doing crowdfunding, then that's your opinion. But please stop thinking that open source software is something people are doing for free on their spare time just for the pleasure (and bank account) of hardware resellers.


Oh, BTW, let's take a tour on ebay. There is currently an auction for Action Replay cartridge with Pseudo Saturn Kai v6.324 (latest version) pre-installed. Unit price is USD 60, 7 cartridges are in stock and 74 cartridges are already sold.
Now let's go on play-asia. Price for one Action Replay cart is around USD 30.
Now, quick math time ! 74 * (60 - 30) = USD 2220 gained so far. Not bad for pre-installing a free software that everyone can download from my homepage.


Back to the main subject : if I open a cowdfunding page to get some specific features to be implemented, that's for good reasons :
- I won't implement these features for free ... see above for the reasons why
- I'm confident these features can be implemented in a reasonable amount of time : if I'm not sure about a given project then I usually don't write about it on my homepage or in my blog





You don't need to detail about Save Data Manager and Gamer's Cartridge details : @privateye knows about them way more than you.

So, I stated that Save Data Manager won't be available in lite firmware, but that was a long ago. After that, I lost time to assemble more Gamer's Cartridge and "all-in-one" carts have their own hardware issues. As a result, there are currently very few solutions to get both Pseudo Saturn exploit, cheat codes and backup memory feature available on a single cartridge.
I still have few time for firmware development, so in exchange of Gamer's Cartridge not being available I would like to provide a similar feature for lite firmware. It won't be as convenient as in Gamer's Cartridge (because of lack of in-game support, and not being able to access SD card etc), but better than nothing.




Of course, let's install Pseudo Saturn Kai on the cartridge. You can even install it twice, which is great ! But let's no forget to claim when its developer begs for a penny.


Last but not least, a forum is a place to share where to share information and everyone's opinion; if you want to unilaterally post something, then an homepage or a blog with comments disabled shall be more convenient.
I'm taking care of Pseudo Saturn Kai official thread, where a lot of people arrive to ask why a game doesn't boots (usually a lens or CD-R problem), or why it doesn't play correctly (because expansion RAM of their cartridge is defective), and I don't kick them because "your post is rude, get out of my thread, bwah bwah !".


End of discussion from me here. Sorry for the trouble caused and I wish you an happy cartridge modding.
i don't know who privateye is so i don't know the extent of his knowledge and i'm sorry if i came across rude i just didn't appreciate him posting links to someone else's stuff here, maybe i over reacted and if i did i apologise.

as to you having crowdfunding i have nothing against it and i'm glad you do, so if you thought i felt otherwise then i just want to to know i don't.
you deserve all the support people can give you.
 
Just wanted to add with this mod it's possible to enable direct save support on the second bank by flashing a Memory Card Plus firmware to it. Since I rarely use codes I just leave it on bank 2 and am able to both save to cart and use RAM games with no issues. Pairs great with a Fenrir.
 
Does this mod maintain the ability to use the 1/4 MB ram expansion, or is there any other loss in features? Why does the board have two eeprom chips? I'm planning on doing this mod for my AR cart and I'm just curious to understand more about it. Thanks for the great post and excellent instructions!
 
I have a technical question that doesn't seem to have been addressed fully.

How is this mod even possible?
I assumed that the pair of EEPROM chips were being used as one storage space for the cart's ROM.
With each chip having 256KB each, totalling in 512KB.
And this storage is not only used for the Action Replay ROM, but also where the backup save data was stored.
I also understood it as the Pseudo Saturn ROM actually used the majority of that (total) space in the past, thus why the old versions of Pseudo Saturn omitted the cheats engine and save backup function, as the space that was allotted to the Action Replay as writable storage for additional cheats and save files was partially filled with Pseudo Saturn data, and thus the corruption issues of old.

But, from what I have taken from this mod has changed how I think about the way the cart is constructed.
From what I now assume are the EEPROM chips actually 'clones'. And act as a kind of backup for one another?
And that is how the 'switching' is implemented?
So in 'stock' configuration the cart sees both EEPROM chips as one single chip. Similar to having 2 drives in RAID 1, with both drives having identical data, acting as a 'backup' for each other.
But, this mod 'separates' the EEPROMS to act as independent storage, with the switch physically disabling one chip at a time.

I guess what I'm actually asking is that in performing this mod; when running in 'stock' Action Replay mode is there any added limitation in the extra codes/save space storage available to the user?
And are there any long-term issues that could present themselves in the future by 'separating' the EEPROMs?

Although I'm a competent electrician; EEPROMs and their capabilities are a little outside my knowledge base.
 

antime

Extra Hard Mid Boss
But, from what I have taken from this mod has changed how I think about the way the cart is constructed.
From what I now assume are the EEPROM chips actually 'clones'. And act as a kind of backup for one another?
And that is how the 'switching' is implemented?
The eeprom/flash chips are connected in parallel. The cartridge bus is 16 bits wide, and one chip stores the most significant 8 bits of every address, and the other the least significant 8 bits.

The mod simply forces the highest address bit high or low, changing which flash memory location the Saturn sees at a particular address. One obvious downside is that any software that assumes the full memory range is available may end up writing over the wrong flash locations.
 
The eeprom/flash chips are connected in parallel. The cartridge bus is 16 bits wide, and one chip stores the most significant 8 bits of every address, and the other the least significant 8 bits.

The mod simply forces the highest address bit high or low, changing which flash memory location the Saturn sees at a particular address. One obvious downside is that any software that assumes the full memory range is available may end up writing over the wrong flash locations.
I appreciate the reply, and your explanation of what is going on.
However, it's still somewhat unclear to me.
Although not intentional the way I'm interpreting your explanation is a little contradictory.

Allow me to elaborate...

If the chips are in "parallel", I would assume that they are seen by the device as one single chip, with the pins of one chip physically connected to the same tracks as the pins of the other.
And they are read and written to simultaneously.
The same as I understand the fundamental way Raid 1 in HDD's works with both storage devices having identical data on them, but is accessed from the entire array to speed up transfer rates. Only these EEPROMs are using a system on a more basic level.
So even though both chips are present the total storage is the capacity of only a single chip. In this case 256KB (2Mbit).
And from your description half of the data is read from one chip and the other half from the second chip. Again, similar to how Raid 1 works.

Or have I misunderstood?

Because in your next sentence referring to how the software may overwrite data.
I assume you mean like how a fake-flashed USB/SD storage device 'loops' back over itself when the data being written goes beyond the 'real' capacity limit but the software doesn't know.
And the way I interpreted your words is that something similar occurs in this mod; once the 'real' storage space of one chip is full; it just 'loops' back over to the start again, and keeps writing, oblivious and regardless of what data it is writing over.
So, that suggests that the chips are more similarly set up in a Raid 0 configuration with the data being spread over both chips in segments, meaning that the total 'true' capacity of the EEPROM is both chips together; 2 x 256KB = 512KB (4Mbit).
And the mod instead forces, or 'fools' the cart to just keep accessing the same chip for both halves of the data, rather than accessing the first half on one chip then moving to the second for the second half.
Which suggests that the chips don't store the same data in the default setup. Just as how a Raid 0 array spreads it's data across all of the connected devices, with the theoretical capacity of the entire setup as all the available space of each individual device added together.

As I mentioned I'm not all that familiar with EEPROM chips, and how they are implemented and used does confuse me a little.
They are confusing components; like how some chips larger capacities are split into 'banks'. And all of the 'banks' aren't accessible at the same time, and need the chip to be signalled to allow access to each one.
I get the principle; it's like changing any kind of storage disc, but the selection is redirected electronically instead of having to physically replace the 'visible' storage.
And from what you have written I kind of get that these EEPROM chips are set up as 'banks' individually. And the cart swaps between the two.

Another possibility is that I am completely misinterpreting how the cart is constructed and the 'storage' I am referring to isn't part of the EEPROM chips at all, but actually contained in the other chips on the board.
So, although each EEPROM chip can function independently, they actually share the 'extra' storage accessible for save data and the cheat code database, so whatever software is 'flashed' onto one EEPROM chip is totally oblivious to what data the other chip has written.
 

antime

Extra Hard Mid Boss
One chip holds all even-numbered bytes, the other all odd-numbered bytes. With two 2-megabit chips, the total storage is 4 megabits.
The memory is presented as a linear array of addresses, and this mod essentially cuts it in half. The position of the switch determines if you're using the first or second half. The risk of error is that the next flash address after 0x1FFF... isn't 0x2000... as expected, but 0x0000...
 
Hey guys here is a simple mod i have done to my Action Replay 4M Plus cartridge so i can dual boot the Action Replay firmware as well as the Pseudo Saturn Kai Lite firmware or a different firmware, For anyone interested here is the guide i've done.

This guide is for Action Replays with 2x 29EE020 eeproms, Board may look slightly different to mine.

Why do i need this?
If you're looking to get Pseudo Saturn Kai or try some other firmware and already own an Action Replay 4M Plus or you have already flashed Pseudo Saturn Kai Lite to your Action Replay 4M Plus then this maybe of interest to you, With this mod you will be able to flash/reflash the Action Replay firmware to your cartridge and then using the switch flash Pseudo Saturn Kai Lite or something else to it as well and then have the ability to switch between the two so you have the benefits of both.
If you have any questions please feel free to ask :)
Very Good

Mine is already with pseudo saturn. If I do this schematic, how would I put the original ActionReplay flash back into the cartridge?

Thanks
 
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