Modchip install for playing PS1 backups only

[jmjohnson85]

The way I see it, PS2 modchips are essentially pointless anymore with OPL/ESR/HDL etc..

As far as playing PS1 backups, however, modchips still have the upper hand.

Yes I know you can use PSXLAUNCHER.ELF or even uLE, but this still doesn't give you the ability to play multi-disc games like Xenogears without using a modded system or emulator to handle the disc switch.

So my question is: Does anyone know if it is possible to install a simple modchip that only adds the ability to play PS1 backups?

When this thought crossed my mind I was thinking it might even be possible to use an old MM3 (12c508a) modchip.

If not that idea, well I found these super cheap $4 Modbo chips at ***********. I was thinking if I connected only the Y S Pos Neg and Reset wires, this should allow PS1 backups... Hopefully..

Any insight into or maybe even experiences with this?

[TnA]

As far as I know, atleast some if not all PSX-Chips should work in a PS2, too.
All they're doing is sending the SCEX-Signal thought.

Yepp, such a 30-50ct-PIC with some code on it as a PS1-modchip + FMCB and some Homebrew is the cheapest and also the best solution thought.

1. You can start PS1-Imports&Backups directly.
2. Nothing in RAM is patched thought, so it stays fully Homebrew-Compatible (all modchips interferre with Homebrew in some way).
3. I guess the old swap-method like with Action-Replay-Max and the old Neo-Chip is possible this way also, so you could even load PS2-Nonpatched-Backups/Direct 1:1-Copies with it (after you pre-booted with a Retail-Disc, but atleast this method will let you use the EJECT-Button there-after... I think uLE would come in extra-handy here.).



So my conclusion is,...
If I really would need to use the laser, while playing all sorts of backups&imports with various ways and while keeping the highest compatibility for Homebrews, I definetly would go for a cheap PIC and flash it myself.

It's not that hard to solder the SCEX to the drive, then for example doing it perfectly for the BIOS-PINs.

Maybe others post their opinions, too?!

Btw.: Maybe HDPRO would be something for you.
The CDVD-Patch-Points should still work (as stated by someone related to the HD-PRO-Team).

[jmjohnson85]

As far as I know, atleast some if not all PSX-Chips should work in a PS2, too.
All they're doing is sending the SCEX-Signal thought.

Well that's what I was hoping for, but I am not sure which pin on the PIC to connect to SCEX (same as SX point right?)

Yepp, such a 30-50ct-PIC with some code on it as a PS1-modchip + FMCB and some Homebrew is the cheapest and also the best solution thought.

Not sure if I completely understand you here. My goal is to directly boot PS1 backups without any homebrew or exploit other than the programmed PIC modchip. Also, the mod needs to have the ability to constantly inject the boot code so that multi-disc games are still accessible after the disc switch.

So my conclusion is,...
If I really would need to use the laser, while playing all sorts of backups&imports with various ways and while keeping the highest compatibility for Homebrews, I definetly would go for a cheap PIC and flash it myself.

Well I have a bunch of 12c508a chips laying around, some already programmed with MM3 hex that I got from the eurasia.nu downloads page. If MM3 works for this then that would be fantastic. I think most (if not all) of the old PIC mods use the 12c508 so I should be good on that either way.

It's not that hard to solder the SCEX to the drive, then for example doing it perfectly for the BIOS-PINs.

As long as SCEX is the same as SX, then I totally agree with you.

Btw.: Maybe HDPRO would be something for you.
The CDVD-Patch-Points should still work (as stated by someone related to the HD-PRO-Team).

I'm quite certain HDPro doesn't allow PS1 backups from HD. Plus it requires a full install of Modbo4, which is exactly what I am trying to avoid.

I am very content with using OPL for playing PS2 backups. I enjoy the idea of a purely softmodded console, but given the somewhat lacking functionality for playing PS1 backups on such a console, I am hoping to resort to a simple hard-mod that can accomplish this.

Well it sounds like I am on the right track at least. But what I really need to know now is which pin on the PIC to connect to SX on the PS2 board? (I suppose I could figure it out through process-of-elimination but a conclusive answer would be nice)

[TnA]

Well that's what I was hoping for, but I am not sure which pin on the PIC to connect to SCEX (same as SX point right?)

Yes, SCEX = SX.
Some modchips state SX and a few SCEX.

Not sure if I completely understand you here. My goal is to directly boot PS1 backups without any homebrew or exploit other than the programmed PIC modchip.

Yes, that was just to explain that it also would be the perfect extention for FMCB.
You do not actually need anything beside the PIC 'connected' and PS1-Imports&Backups should run.

Also, the mod needs to have the ability to constantly inject the boot code so that multi-disc games are still accessible after the disc switch.

I think not all hex&sources have the ability.
But I guess (at least if I remember correctly), garyopa's sources should include it.
Maybe it is worth to look at 'xianaix's old website', too.

Well I have a bunch of 12c508a chips laying around, some already programmed with MM3 hex that I got from the eurasia.nu downloads page. If MM3 works for this then that would be fantastic. I think most (if not all) of the old PIC mods use the 12c508 so I should be good on that either way.

Yepp, that should be fine.

As long as SCEX is the same as SX, then I totally agree with you.

Then we are on the same line.

I'm quite certain HDPro doesn't allow PS1 backups from HD.

Nope. PS2PSXe is the only thing, which supports loading PS1-Games from other 'mediums'/devices, than CD.

Plus it requires a full install of Modbo4, which is exactly what I am trying to avoid.

Actually, it does not require a full install.
You can leave the CDVD-Points, whitch ptch the cdvd-controller.
I'm not sure, which BIOS-Points are needed thought...

I certainly understand why you're looking into an 'as-modfree-as-it-can-be'-solution, hence why I even posted some pro's of using this PICs, for example with FMCB or if you still want to start other Homebrew.

I am very content with using OPL for playing PS2 backups. I enjoy the idea of a purely softmodded console, but given the somewhat lacking functionality for playing PS1 backups on such a console, I am hoping to resort to a simple hard-mod that can accomplish this.

I think one of those PICs, will do it nicely.

Well it sounds like I am on the right track at least. But what I really need to know now is which pin on the PIC to connect to SX on the PS2 board? (I suppose I could figure it out through process-of-elimination but a conclusive answer would be nice)

Well,... there aren't to many wires,...
But I suppose, you can find pictures about those PICs, using google, or whatever you prefer.

If I stated something wrong, someone hopefully corrects me.

[jmjohnson85]

After looking through all of the diagrams for the MM3, I decided that SX was probably either pin 5 or 6.

I connected pin 1 to 3v and pin 8 to ground. Then I proceeded to connect SX here were my results:

pin 6,5,3 - both originals & backups not playing
pin 4 - only originals play (just like no mod)
pin 2,7 - laser won't even light up

So apparently I must need to connect more than just SX... I thought point Y (modbo diagram) had something to do with booting PS1 games. Am I wrong?

[Klink]

the easy way to solve this problem is connect all the wires to the correct places and bam everything you wanted should work

all this time you have taken to try and find the wires only needed for PS1 backups to work

you could of used that time wasted to just install all the wires to the correct places and have a working modded PS2 to play PS1 backups

am i right or are you on a shortage of wires or something

[jmjohnson85]

Are you thinking I am trying to install a PS2 modchip? If you read the thread you would know that I am trying to install a MM3 (12c508a) PS1 modchip into a PS2 - which of course there are no diagrams for.

[TnA]

I think, there might be some diagrams for that somewhere.

[jmjohnson85]

Really? Well then please hook me up because they are nowhere to be found!

Edit:
Wait... Why didn't you mention this earlier? ::evil stare::

[Klink]

Are you thinking I am trying to install a PS2 modchip? If you read the thread you would know that I am trying to install a MM3 (12c508a) PS1 modchip into a PS2 - which of course there are no diagrams for.

yep sorry I just read your post wrong

have you tried looking at PS1 diagrams too see if you can find any tips or compairisons i know it will be completely different then a PS2 but it might help some how and it woulden't hurt. That modchip is a 8 pin right? if so you could use this site too look at 8 pin installs in to a PS1 the stealth2 they name on there site is the MM3 they use if i remember right

http://www.mod-chip.bz/Playstation/installe.html