I finally cracked how the PSP-1000 controls its voltage rails — it goes through
the **Pommel*\*, a DC-DC converter chip sitting behind the syscon. This is the
mechanism behind the overvoltage control in PSPFatSave v981.

**⚠️ This is a hardware-damage warning, not a joke.*\* You can permanently damage
your PSP with this. Only try it on a unit you can afford to lose, back up the
Memory Stick first, and if anything seems wrong hit the Rail Defaults restore.

## How the voltage actually works

The PSP's core (Allegrex), DDR, and several other supply rails aren't set by the
main CPU directly — they're programmed through the **syscon*\, a small serial
microcontroller, which drives the ***Pommel**** DC-DC controller. So the chain is:

```
CPU -> syscon (serial) -> Pommel (DC-DC) -> actual rail voltage
```

There's no datasheet for the Pommel (MB44C001), so this was all worked out from
the firmware and measured on hardware.

## What I found

- **Rail selectors.*\* `sceSysconCtrlVoltage(selector, code)` addresses one rail at
  a time. On a TA-081 Phat: selector 1 = Tachyon core, selector 3 = DDR, and
  selectors 2/4/5/7 are **unidentified*\* rails. Each maps to a Pommel register as
  `reg = 0x0F + selector`.
- **The codes.*\* Voltage codes are `level << 8` (step 0x100; the hardware ignores
  the low byte). For the core rail, **smaller code = more volts*\.
- ***Factory binning.**** Stock voltage isn't fixed — it's read from a fuse register
  (`0xBC100098`), and Sony bins each chip. Some units have zero headroom above
  stock; the stock code is already 0x000.
- **The Pommel never forgets.*\* This is the sneaky part: the Pommel **keeps its
  register values across a warm reboot AND a syscon hard reset**. Only pulling the
  battery and AC clears it. The core rail hides this because the IPL reprograms it
  from the fuse every boot — but DDR and the unknown rails don't get reprogrammed,
  so whatever you last wrote is still live on the next boot. That's why an
  overvolt that "should" be gone can silently come back.

## The actual overvolt

`sceSysconCtrlVoltage(1, code)` on the Tachyon core, stepping the code below stock,
raises core voltage. Combined with the existing raw-PLL overclock this is what lets
a Phat push past 333 MHz more stably than stock voltage alone.

## Where it lives

This is all built into **PSPFatSave v981*\* — the Overclock page now has Tachyon /
DDR / unknown-rail voltage control, plus a **Rail Defaults*\* one-press restore that
puts every rail back to safe values (core to fuse stock, the rest to the console's
measured power-on reference).

GitHub Source
Release

*Everything rail-specific here is measured on a single unit (TA-081v5). Re-verify on
your board before trusting any mapping. Voltage control is NOT recommended for normal
use — it exists for tinkering, and it can damage hardware.*

Code generated 100% with AI. If you can't stand AI, please try to ignore it and don't use my work.

I checked AliExpress and didn’t found anything with good amount of reviews, and on Amazon there’s only ones with bad reviews. Maybe some of you have links? (I live in Germany)

Ps. If you recently ordered shells in other colors and they turn out to be good, leave a comment too pls

I'm looking for a reputable & reliable guide so that I can install CFW on my PSP 3000.

Does anyone have a link to one? Not sure what everyone is using.

I'm trying to upgrade the firmware on my PSP Go from 6.61 Pro-C2 (Infinity) to Ark-5, but for some reason it's reporting that "You're running OFW from a x000 series, it should be for the GO OFW". I'm not sure what I should do to fix this, I'm not even sure the error is correct, since I definitely have Go-specific features like the analog clock and bluetooth. Is there anything I can do to downgrade to OFW and get Ark installed? I've tried several versions of Chronoswitch and tried running the app from both internal storage and the M2 card (Running it from the card causes the error to instead say that it can't find /GAME/UPDATE/EBOOT.PBP) but I still can't get it working. I made sure to download the Go version of the 6.61 firmware from PSPPunk and put it in the appropriate directory renamed to EBOOT.PBP, as well. I am certain this is the correct firmware, since I just used the same firmware file to downgrade a friend's PSP Go yesterday.

Hello there, as the title suggests I am looking for advice about modding. So i found my old psp which had some issues and would not turn on(but works with charger just fine and im waiting for some replacement batteries as well.). How easy is it to mod the PSP by myself and how advised is it if it is an old device that had no parts changed ever? Will that make any difference? It did not use to have any issues at the time, it just randomly did not turn on without being plugged in, but as later discovered the batter was bloated as well.
Also, I have one of those dual slot memory stick duo adapters and what is the maximum storage I can use safely so that it does not cause any issues? and what to consider while modding the console?
P.S. if you could put links of helpful tutorials and the material I will need to use will be even greater help!

Thanks in advance

It took me a couple of hours more but eventually found out I plugged the joystick badly, and now it’s perfectly fine

Hi all,

just yesterday I installled ARK5 and TempGBA with FireRed.
I was gaming all Day and saved multiple times. Had about 5 hrs of Gametime on Pokemon and when I turned it on today the last file it saved was after 3:28hrs. Anyone know what happened there ?

Is there a way to import my game onto the PSP? I have my own small project made with RPG Maker MZ, and I want to import it onto the PSP. How can I import it into the ISO format so that it works?

Hello, I know a bit about Software and Hardware but would like to get your input on a highly specific hardware mod I'm researching.

I’m looking to physically overvolt the CPU of a PSP 1000. My idea is to hack the "Pommel" (Sony's custom power management IC / DC-DC converter) or modify the surrounding hardware. Rather than swapping out standard voltage divider resistors, it looks like this circuit relies on feedback filters. My goal is to manipulate these filters to trick the regulator into delivering a higher core voltage to the processor.

I have the official schematics and PCB layout for reference here:https://smallpdf.com/share-document#r=result&t=10743861ab24e78cf571f03022870b5a&i=share

Since this is deep into uncharted territory for this console, I’d love to get some general advice from people experienced with altering DC-DC feedback loops on densely packed boards:

• Target Voltage: Looking through the schematics, I am targeting the CORE_+1.2V rail. Do you agree that this is the right and only voltage line I need to raise to successfully overvolt the processor? Or are there secondary rails that need to scale alongside it for stability?
• Analyzing the feedback loop: How would you approach pinpointing the specific feedback filter components tied to the CORE_+1.2V generation?
• IC Protections: Does anyone have experience with Sony’s custom power management chips from this era? I'm wondering how aggressive the internal overvoltage protection (OVP) might be if it detects an anomaly on that 1.2V rail.
• General Approach: Any advice or warnings on methodology before I start testing or altering the traces around the Pommel?

(Note: I'm fully aware of the standard CFW 333MHz software overclock; this project is strictly about exploring a physical hardware voltage mod).

Thanks for any insights or help analyzing the schematic!
Maybe a collaboration would be possible where I buy another PSP 1000 and test the hardware mod and someone helps me identifying how to do it.

To anyone whos using the large extended battery in the PSP 2000/3000:

Do you have an issue with keeping the UMD drive closed/the battery compartment fully closed, when you have the big battery in?

I have the extended battery and extended cover on my 3000, but a lil bit of the battery cover sticks out and if i push it in it opens the UMD drive slightly

anyone else have this issue?

I've already made the txt files for games, dlcs, etc.. but the app won't read any of them besides games. Anyone know how to fix it?

I have a Japanese PSP 1000 that got bricked during a software update around a decade ago. I do not remember much about what happened, but I believe I was updating to 6.60.
It turns on, shows the Sony Computer Entertainment logo, then goes to a white screen. No recovery menu.

I also lost the battery years ago, but have charger.

Any way to save it?