View Full Version : Something to consider re: coding for psp

April 14th, 2005, 14:40
There seems to be a bit of a problem coding for the psp, beyond the obvious fact that we don't know how to do it yet, seeing as the dev kit costs $25k and no one (to my knowledge, anyway) has reverse engineered the system to the point of being able to write useful code yet. This discussion is hypothetical.

We do know that code can be executed from the memory stick: you can write an application and run it from there. In fact, the memory stick is bootable, that is to say a bios update from the memory stick will run if you turn on the psp with a memory stick in it.

The problem here is that the memory sticks are either small, expensive, or both. I mean, assuming everything goes well, we'll be able to write programs in a shell that lets us run them by dropping it onto a mem stick, sticking it in our PsP, and running it. Great: so pray homebrew games don't exceed 32 megs of resources? (Yes, I know the sticks go up to a gigabyte, but even that's limiting. It also gaurentees that even if we can make a copy of the data from a UMD onto a PC, we can't take that same UMD and put it onto a memory stick, because the UMD is abou 700 megs bigger than the largest memory stick sony will ever make).

Well, obviously this is good from the perspective of keeping pirating to a minimum. UMD is not a writeable format, and since we can't copy ad write our own disks, it shouldn't be a problem. But it also means that homebrew software can never exceed a certain size: this is a bit of a problem.

I was thinking about the problem of getting additional media onto the PsP: what about the USB connectivity? Supposedly it's their so you can drop network updates from your PC, or store photos/videos to a memory stick, but what if we could do more? How fast, exactly, can UMD read data in when accessing a contiguous segment? How fast is USB 2.0? I wonder if a bit of clever coding would let us feed media from UMD disc images on a hard drive through USB, basically treating the latter as native media. I'm sure someone could write an interphace and a buffer for that...

Second thought. If you could get apps running through the USB cable, why use your PC's hardrive? There are open source drivers for the Ipod, the Nomad Jukebox Zen: what if we used those drivers as part of the interface, and wrote code that let us run UMD disc images from the root directory of an Ipod? We'd have a completely writeable media format that's just as portable as the PSP, and almost as common as a computer.

Basically: could we write a soft mod app that runs on the memory stick and lets us use either a computers HD or a USB based portable drive? It'd be to homebrew on the PSP what writeable game carts were to homebrew on the GBA. If not better, because this setup uses something many people already have (and can use for something other than running homebrew Code, which makes the price tag a bit more justifiable).


April 14th, 2005, 15:04
First roadblock: open source devkit needed. nothing else that you discussed really matters unless you can write code and compile it for it.

April 14th, 2005, 17:09
2Gb Memory Sticks are here but cost $380

April 14th, 2005, 17:26
2 gb mem cards? Interesting... not made by Sony, I'll wager.

And again with the $380 price tag...

But of course, you're right. We need a dev kit.