forums.ps2dev.org

Jabberwocky · Joined: 03 Aug 2005 Posts: 43

Has anyone had any luck writing a general purpose USB communications library between the PSP and PC? I've written a file server system using TCP/IP and WLAN, but data transfer speed is not as quick as I'd like, and it takes a while to setup in the first place. A USB connection would be far better in terms of both speed and setup time (juding by the USB stuff in the shell).

The probelm is, of course, drivers on the PC and PSP side. However there must be some PSP library code to read from the USB, as I've heard there's a way to communicate between PSP and PS2 via USB, but nothing on the PC.

I'm going to investigate further myself, but if anyone else has made any headway it will save me some time and effort.

Matrixdub · Joined: 13 May 2005 Posts: 60

This may be of no help at all, but isn't the PS2->PSP communication hosted by the PS2? I mean, isn't the PS2 reading off the memory stick simply as if it is a bog standard memory card?

I cannot verify because I do not have a PS2.

PspPet · Joined: 30 Mar 2005 Posts: 210

> Has anyone had any luck writing a general purpose USB communications library between the PSP and PC
The simple approach used often is to include the usb-storage code (from the PSPSDK sample) in your app. The PC sees the PSP's memory stick as a storage device to copy data to/from. The PSP can do the same. Good enough if you are happy with copying data to the memory stick first (and latency in "stat"ing files to see when things have changed)

For a more direct connection, there is a "usbpspcm.prx" module for PSP->PSP communications. This can be found in some games. I have yet to find a game that actually uses it [you can load it, initialize it, but I haven't figured out how to get it actually working]

Jabberwocky · Joined: 03 Aug 2005 Posts: 43

No, there is a realtime comms layer for the PSP<>PS2 juding by the different USB driver modes on the PSP. The PS2 may well act as a USB host, but the PSP is not just acting as a USB storage device.

Has anyone actually revered the USB driver code on the PSP to see how the handshaking works? It really would be bloody useful to have a USB PSP<>PC link for dev work.

Does anyone know if there is a way to sniff the data on a USB link ala serial or parallel sniffers? I'd guess not if you wanted to sniff a PSP<>PS2 link, though...

Jabberwocky · Joined: 03 Aug 2005 Posts: 43

Yep, the usbpspcm.prx is what I'm on about... sceUSB_PSPComm_Driver. If there are no PS2 games currently which use the other side of the link, though, it's not going to be possible to do much I don't think...

groepaz · Joined: 01 Sep 2005 Posts: 305

looks like usbpspcm.prx is indeed for psp<->ps2 communications.... from looking at the code i think you need to send some kind of "magic" from the ps2 to the psp to initiate the connection. i have no ps2 though so i've given up on looking at it more closely.....it shouldnt be too hard to reverse for someone with a ps2 game that uses that kind of communication i think.
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cheriff · Regular Joined: 23 Jun 2004 Posts: 262 Location: Sydney.au

The only game like that i've heard of that is msg:snake eater. But i always thought that it just mounted psp as mass storage and read the savegame file.. perhaps its more complex/interesting than that..
I do have the game, but not enough time to look into it.. hopofully one day .. :)

Just had a quick look, and there aren't any interesting irx files. Everything seems to be inside .img or .ipx files in /modules on the cd.. (neither have any plaintext strings in them so maybe i'd need a magic key to open the gate ... )
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DigitalFoundry · Joined: 20 Jan 2005 Posts: 47

I might be wrong but I've been informed that the forthcoming JakX Combat Racing seems to 'talk' with the PSP game Daxter.