PS3 Downgrade a 40nm Frankenstein PS3?

[LucaXCECHA00]

So I watched @RIP-Felix video on the YLOD and I now recently got three Frankies, CECHE01 (40nm), CECHC03 (65nm) and a CECHA00 (40nm).

In his video he said that you cannot downgrade lower than 3.55 on the 40nm models.

However, is there any way to modify the RSX or something in order to downgrade to 2.80 for example for OtherOS?

 

[RIP-Felix]

So, I said 3.55 because that was the lowest FW tested and confirmed working. There is a theoretical lower FW possable. However there are multiple RSX revisions. CXD5300, 5301, and 5302. Baked into the RSX itself is a ROM revisions that is checked by the OS at boot.

It would stand to reason that the earliest revision CXD5300 would have a lower minimum firmware version compatible. Hovever, from what I understand none of those can go low enough for Other OS.

For simplicity we chose a 3.55 because we know all 40nm RSX's support it.

Now to answer your question, someone like @M4j0r or @zecoxao would have to explain if/how the ROM check is baked into the bootloader and FW. I suspect it could be possable to remove that check, or add the rom revisions to enable 40nm. But from what little I understood there wasnt much interest in making a Modified Firmware that does, simce we can use Other OS in current CFW. Albeit not as good as the original implementation. At least, I've heard it's buggy...but I hate linux so I'll let those guys explain.

 

[Joonie]

a while ago, I released an OOS enabled MFW v3.15 for DECR and it does appear to support 40nm rsx roms. at least judging by the lv1 strings in lv1.elf. So I'd think you can install 3.15-3.41 to try out the native OOS support without using OOS+.

The major difference since 4.xx is the support for 28nm RSX and it appears to be that at least 3.15 and up support 40nm RSX.

Notes : I never owned a frankie and never tested this theory to confirm my words.

 

[RIP-Felix]

Right, so if you wanne be the guinea pig we could find out. But if it doesn't work you'll get a GLOD with an RSX ROM abort. keep a hardware flasher handy!

 

[LucaXCECHA00]

Right, so if you wanne be the guinea pig we could find out. But if it doesn't work you'll get a GLOD with an RSX ROM abort. keep a hardware flasher handy!

Alright I'll buy myself a hardware flasher and be that guinea pig hahaha

To further explain my attempt here now that I can see the LV1 strings thanks to @Joonie : Would it be possible in theory to use the FW for 1.03 for example (lowest downloadable) and add the 40nm to the strings?

Because a 40nm 60GB PS3 with the original 1.XX FW installed would probably be the most nostalgic thing I can think of!

 

[Joonie]

Alright I'll buy myself a hardware flasher and be that guinea pig hahaha

To further explain my attempt here now that I can see the LV1 strings thanks to @Joonie : Would it be possible in theory to use the FW for 1.03 for example (lowest downloadable) and add the 40nm to the strings?

Because a 40nm 60GB PS3 with the original 1.XX FW installed would probably be the most nostalgic thing I can think of!

I don't remember trying just hex editing rsx revision.. I doubt it would work.. you can feel free to try if if you got a flasher. I don't think 1.03 can even do 65nm.. i think the lowest you can possibly go would be 3.00 and up. Don't bother going lower than 3.15… you can try checking lv1 on each FW to see which one supports 40nm like I did earlier.

On DECR 1000A, I was able to debrick via ebootrom flashing because my unit got bricked over 0.83 FW while back and my rsx was higher revision than what that 0.83 supported. But that's not an option for your unit. FSM may work but I haven't tried.

 

[RIP-Felix]

Alright I'll buy myself a hardware flasher and be that guinea pig hahaha

To further explain my attempt here now that I can see the LV1 strings thanks to @Joonie : Would it be possible in theory to use the FW for 1.03 for example (lowest downloadable) and add the 40nm to the strings?

Because a 40nm 60GB PS3 with the original 1.XX FW installed would probably be the most nostalgic thing I can think of!

I don't understand the desire for low FW. They don't have safe mode for one. That was added later. The game library will be limited. IIRC PS2 backwards compatibility wasn't as good, there were bugs out the gates that were patched and improved BC over time. And OFC, it's very risky.

I just don't see the appeal.

 

[LuanTeles]

@Joonie, is it possible to create a hybrid firmware with a newer coreOS (lv1 for the drivers) combined with older flash files?


I'd like to go back to around version 0.83 or so and run some firmware-related tests

 

[Joonie]

@Joonie, is it possible to create a hybrid firmware with a newer coreOS (lv1 for the drivers) combined with older flash files?


I'd like to go back to around version 0.83 or so and run some firmware-related tests

As long as VSH is forward compatible I'd think so.. I think you'll have to backport some stuff in LV2 to make it backward compatible with older VSH... if you got a unit with minv 1.00 I think you can at least try out DEX 0.96.. maybe 0.83 is so simple and old enough to be crosscompatible between DEH and CEX or DEX..

 

[Mystyqblaze347]

Alright I'll buy myself a hardware flasher and be that guinea pig hahaha

To further explain my attempt here now that I can see the LV1 strings thanks to @Joonie : Would it be possible in theory to use the FW for 1.03 for example (lowest downloadable) and add the 40nm to the strings?

Because a 40nm 60GB PS3 with the original 1.XX FW installed would probably be the most nostalgic thing I can think of!

Were you able to test/figure out what the lowest you can go on a 40nm frankie for other os/other os++? Debating on trying linux (red ribbon {unless something better}) on my a01 40nm frankie.