PSP Flash Chip Facts: The Good, the bad and the ugly

[wraggster]

McZonk has posted this great article :



With the help of some university lecturer I have removed the flash chip from a psp board. Neither the board nor the chip are damaged. My idea is to build a PSP with 2 flash roms. If I brick one, I can restore it with other one. Everybody how has a bricked PSP can help Team Emergency Exit with giving us the board. I also need some money for build a circuit board to attach two on. Contact: [email protected]

The Good Facts

The chip is a standard chip from Samsung: K5E5658HCM . There is nothing secret with the chip. Everybody can buy it, if you take 1000

The Bad Facts

The chip is not only the flash rom (256 mbit nand rom). It is also the ram (256 mbit ddr ram). If you read though the datasheets of the chip, you will find there figures. The flash is built from nand gates. It won't be as easy as access nor gates. So direcly writing into the flash is not easy.

The Ugly Facts

If you look at the board, you will see the wire loops from processor to the flash/ram chip. These wires are made to keep all wires in the same length. This is important for the timing of the ram and timing is very very cirical. If I brought back the flash/ram on the board with just some small wire brigdes, it could disturb the timing of the ram. The flash is not critical, but the ram is.

I will also try to build a two flash psp.

It seems that the article that was posted here exclusively by McZonk has yet again been stolen and worse the site who stole it is getting credited, our apologies to McZonk about these sites

[jwilds73]

So what is the idea here to add a second chip to the psp and keep one at say 1.5 OS and then the second whatever the newest version is and just have someway to toggle between which chip (OS) you boot?

[jimjamjahaa]

possibly, tho i think maybe it is so you can f**k with the firmware as much as you like and not end up with a brick (backup flash chip)

so you could make your own firmware based on sony's or linux or whatever

[LampDev]

Yeah, if he expects money and psps to test, he should really explain his full purpose.

What does he want these to do? To start an unbricking service for PSPs? To flash PSPs back to 1.0 or 1.5 the hard way?

[eretsua]

would be interesting to see where this could lead. though, i agree that a more elaborate explanation is necessary.

[Hidavi]

256MB RAM? Then why do all the spec lists say 32MB RAM? I think that Sony might've ordered a special version of the K5E5658HCM chip with only 32MB because no way the PSP has 256MB.

[danhans115]

The PSP does have 256Mbits(Megabits) of RAM which equals 32mb (megabytes). Something to do with there being 8 bits in a byte or something..

[alexh]

This seems a bit of a waste of time. As said DDR timing is VERY sensitive, moving the chip onto a second board probably wont work.

I would imagine though there is a test header / JTAG port to allow the Flash to be programmed as the PCB is being assembled (without using the PSP's CPU) that would be the place to look for.

[LampDev]

From the guy's site:

The concept is to build a PSP with two flash chips on. This will be very helpful vor developer because if one firmware is damaged it can be reseted.

I wouldn't give anyone anything who screws up the english language that much in two short sentences. On top of that, there's STILL no information as to what they plan to do once they do get one working. I'm guessing they plan on selling the modded PSPs.

[PSP_Newbie]

I would assume the grammatical and spelling errors might be due to living in another country in which english is not the primary language
just wanted to bring this up as almost every time i see bad spelling in a release comment like this it is due to them not being a native english speaker, and someone always brings up their ability to speak english with the unrelated software/hardware-related comment, but then i could be wrong