Memory card system not compatible with save states

[tcaudilllg]

While playing Valkyrie Profile on pSX v.1.10, I came upon an obscure issue of relationship between the save state system and the digital memory cards system. Particularly, the save state system records the memory card status along with the rest with the hardware. When a save state is recalled, the memory card is recalled along with it, even if the memory card is not currently in use by the virtual machine. This "ghost" memory card is unable to save information; further, it seems impossible for a save state to work the memory card system. Even if one removes the current card file and replaces it with another file, the save state will be unable to work with the new file.

There are also issues with instruments shorting out during select dialogue scenes (conversation with Gannos at the Dragon Temple, and the A-Ending sequence) and subsequent unresponsiveness. (although the music continues to play and the dialogue recall window continues to be operational, strangely enough) Obviously these latter issues are matters of incompatibility, but I digress....

[patrickp]

I'm not sure exactly what you're trying to say here, tcaudilllg. Some emulators (AIR ZSNES does this) certainly do have the regular saves linked to save states: load from a save state with different regular saves in ZSNES, and you find your old regular saves are overwritten and lost. Can be very annoying. This is not so with most emulators, though, and certainly not with pSX.

I think what you may be referring to is a well known problem that running a game on save states for some time without saving to a memory card, and loading the game anew from the save state, allows errors to creep into the game. Regular saving to a memory card and restarting the game from the memory card save tends to eliminate these errors. I warn people about it quite often.

This is not so much a bug as an inevitable consequence: running on save states is like running the game continuously: with such a complex activity, there is room for errors to accumulate. Saving to a save state preserves these errors and thus they are still present - and becoming worse - when you load the game again from the save state. One consequence of this is that the game may now deviate sufficiently from what it should be to prevent the player being able to make memory card saves.

However, a memory card save is not a 'snapshot' of the game, as a save state is, but a record of various parameters in the game. Hence, if you save to a memory card, restart the game and reload the memory card save, it's not like continuing the old game, it's like starting a new one, but at the point in the game where you were before restarting. This will normally eliminate any errors that might have occurred while playing.

My advice is to use save states as much as you like during a game session, but always to save to a memory card at the end of the session, and restart from the memory card save.

I think you need to elaborate a little more on the way you're using save states and memory card saves: it's not really clear what you're trying to describe. In particular, I don't think that a save state records anything in hardware: pSX emulates entirely in software and the software state is what will be recorded in a save state.

Have you done a search on Valkyrie Profile? I'm not sure, since I don't have the game myself, but I think the issues you refer to in your last paragraph have been reported before; possibly several times.

Also, it would help if you could provide a little more information on how you're playing: for instance, since you seem to be referring specifically to Valkyrie Profile, which version of the game you're using (i.e. the game ID), what BIOS you're using and whether you're playing from CDs or images. Is there any reason you're using v1.10 of the emulator rather than the current v1.11?

[tcaudilllg]

I don't think that a save state records anything in hardware: pSX emulates entirely in software and the software state is what will be recorded in a save state.

And that's exactly what I meant to say. I was refering to the "hardware" metaphorically. Particularly I intended to convey that the memory card information is saved along with the state.

The solution to me seems quite simple: cut out the memory card data from the save state. And I am certain that is the case, that the memory card data is being saved along with the rest of the simulated hardware status. I see where you are coming from with your "free radical" hypothesis, but it seems to me those "errors" would bring the system to a total halt. But I don't want to argue with you about it.

I'm just making the recommendation that the save state system's relevant contents be carefully scrutizenized in preparation for the next version.

As it is I'm at the end of VP on Hard Mode after some 50 hours of play, (my intention is to finish the Seraphim Gate in full) and unable to get past the A-ending sequence. No problem if I could save the game and play the scene on another emulator, but....

Now why I save my game to a save state in the first place? Because the cards I had were full and I never suspected the relationship between the save states and memory card systems was flawed. A weakness of mine, admittedly. I just never expected to be in this position from the start.

I should say further, that I have programming experience and am at least somewhat aware of how these systems work. (though again, I'm not looking for an argument with anyone.)

[patrickp]

You can create as many memory cards as you want, tcaudilllg. No need to stop saving because your cards are full - just create some more!

So what makes you think a 'phantom memory card' is saved in a save state? It doesn't really sound that likely to me - particularly as it has been established that the scenario I described, that errors start occurring in a game session that is protracted in save states, does occur - and the errors often do not bring the system to halt, but can affect the likelihood of being able to make a memory card save successfully and cause other problems in the game.

As I said, some emulators - most notably ZSNES - certainly do retain regular save information in save states. I don't think this occurs in any Playstation emulator, though, apart from the fact that, obviously, the parameters loaded by the memory card form part of the game 'snapshot' saved in a save state.

Also, you can change memory cards in the course of a game and they'll still work fine - certainly in games that I've done it with. This would suggest to me that the emulator cannot be recording any information about the memory card, certainly not in a way that would interfere with the use of different memory cards. You may have noticed that it's usual for a Playstation game to check the memory card when you go to load or save a game - this suggests that it doesn't keep a record of it, or it should be able to access the memory card without a delay.

It's possible, I suppose, that there are certain games that may retain memory card information as part of the game, as you describe, but in that case, it would be a function of the game, not the emulator.

[jking]

patrickp said:

Some emulators (AIR ZSNES does this) certainly do have the regular saves linked to save states: load from a save state with different regular saves in ZSNES, and you find your old regular saves are overwritten and lost. Can be very annoying.

This is a relatively new mis-feature, as I recall. In any case it can be turned off from the "Saves" dialogue ("Load state w/SRAM"). Snes9X used to (and still does?) do that back in the day, too---it made SRAM saving virtually useless.

[patrickp]

Ah, thanks for that, jking - no more losing saves for me!

[tcaudilllg]

Well I intended to get the attention of psxauthor, and I'm sure I have. He'll know better than anyone. Perhaps in a later release of the emulator we'll see this problem mentioned or dealt with?

It's possible, I suppose, that there are certain games that may retain memory card information as part of the game, as you describe, but in that case, it would be a function of the game, not the emulator.

VP doesn't seem to do this. I've got an intuitive hunch that the save state information is recording memory card information. (if not even all of it.)

You say the issue is a problem of accumulating free radicals (errors) corrupting the save state. This question can be solved quite easily: start a new VP game; save the state data with a full memcard file loaded; recall the data; change the card file; and attempt saving. I will try this and report my results.

[patrickp]

That should do it, tcaudilllg.

BTW, could you provide the information I asked for earlier, please?

Also, it would help if you could provide a little more information on how you're playing: for instance, since you seem to be referring specifically to Valkyrie Profile, which version of the game you're using (i.e. the game ID), what BIOS you're using and whether you're playing from CDs or images. Is there any reason you're using v1.10 of the emulator rather than the current v1.11?

[tcaudilllg]

I just hadn't updated. In particular, because I usually the internet away from home. (at the community college I attend) I've got to save it to a media form... I just hadn't gotten around to it.

BIOS: SCPHBIN1001.

How do I find the game ID?

[patrickp]

Thanks, tcaudilllg - game ID is a number on the spine of the game case in the format S###-***** where # is a letter and * a number. It's often on the label of the CD, as well, especially if it's a multi-CD game.

Otherwise, if you browse the CD or mounted image, you'll find a file, almost always on the root but occasionally in a subfolder, with a name in that format. That's the game ID.

Edit: the game ID tells us what video format and region the game is, and also which specific version when there have been more than one issue.

[Deleted]

And here's a picture to boost that post.




Also, déjà vu!

[Ultima]

I've had this same thing happen to me in other emulators. Seeing as how save states are only dumps of the emulated hardware's RAM, it has nothing to do with it saving the memory card data. My guess? It's an issue with the games storing whatever data they want in RAM, and in your particular case, it's probably storing the memory card data (or the list of saves in the memory card) in RAM, and pSX is simply writing that data to RAM.

Wikipedia

Memory
Main RAM: 2 MiB
Video RAM: 1 MiB
Sound RAM: 512 KiB
CD-ROM Buffer: 32 KiB
Operating System ROM: 512 KiB
PlayStation Memory Cards have 128 KiB of space in an EEPROM

That's 2048+1024+512 KiB = 3584 KiB of main, video, and sound RAM. Now, save states are 3721 KiB, but those are probably other bits and pieces of data that pSX stores (and maybe file storage formatting, though I doubt that), but it almost certainly isn't the memory card, as having zero, one, or two memory cards inserted nets the same result: 3721 KiB for the save states.

[tcaudilllg]

Well I tried reproducing the error by means of the Seraphic Gate. There were no issues until I tried loading in a full memory card in place of the one I loaded the Seraphic Gate from. VP projected the previous card's save headings (which seem to include only location, with everything else, even experience level, reported as 0 and the game rank set to "Easy") onto the full card, highlighting the corresponding save blocks in turquoise blue. This, even though the card was loaded with 15 FFVIII save files. VP saved its data over the FFVIII data.... When examined in the bios the VP save file was not discernable, however.

Furthermore, it was possible to save the game state (via quicksave) before this illegal overwrite took place. When this happened the memory card's state was "restored" to its non-illegal state. Also interestingly... the illegal save is treated by VP as a perfectly legitimate save file which can be loaded from right away, even though it does not physically exist on the card file.

It was possible to reproduce this scenario in the lastest public release of PSXeven. (1.7? I forget... it's the one at Zophar.net) This seems to indicate that either the issue is unrelated to pSX specifically...or that both emulators use a very similar save state mechanism.

I am further perplexed by the nature of my original problem; that is, how did erroneous data enter my VP Hard Mode game? I experienced my problem early on... on the first disc, in fact, Chapter 3 at the latest as evidenced by my quicksave. That must mean that for someone to fully explore the early stages of the hard mode... means they cannot save their data!? All of this is perplexing and confusing.

[patrickp]

As I said before, this sounds to me like a game issue rather than an emulator one. Can anyone else reproduce this behaviour, and can it be reproduced in a Playstation?

tcaudilllg: could you post your game ID, please? Also, have you tried what you said you would do earlier?

start a new VP game; save the state data with a full memcard file loaded; recall the data; change the card file; and attempt saving. I will try this and report my results

[jking]

patrickp said:

Ah, thanks for that, jking - no more losing saves for me!

Win!