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RPG Maker - PS1 Larger Memory card support?

Started by krum110487, March 01, 2012, 01:28:29 PM

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I am going to start off by stating what I have done/tried:

Ok, so I recently collected a bunch of RPG maker games, some of which takes up to 9 memory cards, while most are around the 3 range.

So I got to thinking, man, I wish playstation would allow larger memory cards or more cards so I wouldn't have to worry about switching them! So I got a copy of PCSX-r source code, compiled it and started tinkering. I was hoping to use the built in bios, but RPG maker was not compatible with them.

I am pretty sure I can modify the emulator to use more than 2 memory cards, but since the original psx bios only look for 2, that will be an issue. So I attempted to disassemble the bios and figure out where it is loading, although I think I am doing this part wrong as it seems to show opcodes that didn't exist or weren't on the lists I found, although it could be that I was using documents that were incorrect.

long story short, I am stuck trying to figure out the asm for the bios to force it to recognize either more than 2 memory cards, or larger ones. I know I will eventually need to add support for more than 2 memory cards within the game as well, but for now I want to get the bios recognizing them.

Here are my questions to you:
Is it feasible to add more cards to allow the entire game to be loaded at once?

Anyone have suggestions of what program to use and the settings to decompile or disassemble playstation executables and the playstation bios? I have tried a couple, but as I mentioned above they seem to have different opcode names from what documents I have found, which confuses me a bit, and I think I may be doing something wrong.

Does anyone know of any documentation on playstation specific opcodes or is it simply an r3000 opcodes set? I have looked around, but haven't found anything worth while.

Alternate possibilities
RPG Maker comes with a game sample which is in COMDATA.bin, it seems to be a nearly 1:1 copy except the empty space was compressed, and it seems some words, although I haven't figured it out yet, this may be a much better solution, if I could simply take the games from memory card and compile them into a COMDATA.bin. The main problem with this seems to be that there are a lot of unknowns here for me, such as header data, how the format differs if at all etc...

If anyone is interested in helping at all, that would be awesome, even if it is just finding the asm or function that is checking for the memory cards, it would be a great help!

thank you for your time! ;D


Doesn't the PS1 technically support up to 8 memory cards via a use of two multitaps?

(With supported games referring to them in text as Port 1A~1D and Port 2A~2D)

Can't really think of any games off the top of my head that actually did support multiple memory cards (beyond 2) on the PS1, but maybe something like the sports games (at least the EA sports titles did on the PS2). Could be worth to take a look at some of those, in an attempt to try to comprehend how to feed the system more than just two cards at once. Guess Japan might've had some multitap enabled stuff too (best is to look for games with character customization and multitap support).


After some research, there is nowhere saying that RPG maker supports, multiple memory cards, I can't even find a game that would manage more than 2 at a time, I think the 4 memory card slots were just in case, so someone could program support for it in their game if they wanted.

which leads me to believe either the bios already supports 4 to 8 memory cards (un-managed, but recognized?) or the game itself would have to program access to them?

If anyone knows a game which supports more than 2 memory cards for saves, custom stuff...anything, that would be a great start, I am looking now.


Sorry for the OT... EA Sports supporting MULTIPLE memory cards? (So I hear) later EA Sports games taking up an ENTIRE 8 MB memory card just wasn't enough, they needed MORE? How greedy. :P
(not being a fan of "real" sports games, haven't played them myself. Though I could imagine a point for supporting multiple cards for multiplayer.)
"My watch says 30 chickens" Google, 2018


so EA sports on the PS1 use multiple memory cards? that would do, then maybe all I will have to do is add more memory cards on the emulator and try to get it to recognize them!

I will mess around with this.


If you are talking about a emulator solution only, would it not be more easy to just hack the memory card to be bigger (more than 15 blocks if my memory isn't wrong)??

As for an hardware solution, maybe modify the drivers of this to make real time save on the pc.


Well that memory card is great for a ps2, I have tried making my own memory card with 30 blocks instead of 15, but the emulator will simply ignore it, even when I modify the code to accept larger memory cards. (unless of course I simply did it wrong, which is also a possibility :-P)

I think this is due to the fact that the bios will only accept 15 blocks, I can also confirm that not one PS1 memory card is above 15 blocks, they have some that are like "9 memory cards in 1" but not truly more than 15 blocks, it has a button to change the memory card (assuming all memory card access goes through the bios, I am still kinda wondering that too).

so I have one of three options.

A) make the memory card larger, and make the bios support it, as well as the game to support it.
B) make more memory cards available and make RPG maker look for them (not sure if this would include editing bios, yet)
C) figure out how to take the saves and compile them to work in place of the sample game, which seems to be the easiest, although I can't get a handle on the compression to the memory card saves vs the comdata.bin

does anyone have any input or good documentation on PlayStation assembly and PlayStation disassembly?


Oppss...sorry..I forgot memor32 is for ps2 and not ps1.

From what i know, the 9in1 memory cards, have multi layer of 15blocks so i believe there is a limit on the bios.

I would send a PM to Gemini.
He probably never have done something like that either but he is the PS1 Guru here and sure can help you in some ways.