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Easier Way For Usb Nand Dump Than Lpc2148?


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#1 firebuddie

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Posted 15 December 2009 - 12:27 AM

Folks, I have just puckered up courage to share my thoughts and risk ridicule...

Well I have jasper 512nand. As we know it is a ballache to dump using LPT so 'high performance' olimex lpc2148 usb now supported in nandpro2b. I'm guessing the nandpro performance is all down to port throughput data rates, whereby USB has 12Mbps data throughput compared to standard parallel port throughput rate of 150kbs.

But if it is ALL down to LPT port data thru put limitations, then why use the complicated olimex usb lpc setup? Why not simply connect the male db25 connection from the xbox mobo to a female db25 parallel printer cable which has a usb connection to pc? Or would a Parallel Printer Port Cable 25 pin female connector not be compatible with nandpro2b libusb driver? If not, surely we could find a cable driver that would work with nandpro.

Using this simple single usb Parallel Printer Port Cable 25 pin female connection would sure make life easier for big blockers and a lot cheaper to boot!

I am conveniently ignoring any of the voltage considerations on the premise our good friend mr resistor could help us it out if required.

PS No doubt this idea has been thought off before but I thought I'd ask the gurus anyway...

Edited by firebuddie, 15 December 2009 - 12:39 AM.


#2 DiaM0nd99

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Posted 15 December 2009 - 12:47 AM

QUOTE(firebuddie @ Dec 15 2009, 12:27 AM) View Post

Folks, I have just puckered up courage to share my thoughts and risk ridicule...

Well I have jasper 512nand. As we know it is a ballache to dump using LPT so 'high performance' olimex lpc2148 usb now supported in nandpro2b. I'm guessing the nandpro performance is all down to port throughput data rates, whereby USB has 12Mbps data throughput compared to standard parallel port throughput rate of 150kbs.

But if it is ALL down to LPT port data thru put limitations, then why use the complicated olimex usb lpc setup? Why not simply connect the male db25 connection from the xbox mobo to a female db25 parallel printer cable which has a usb connection to pc? Or would a Parallel Printer Port Cable 25 pin female connector not be compatible with nandpro2b libusb driver? If not, surely we could find a cable driver that would work with nandpro.

Using this simple single usb Parallel Printer Port Cable 25 pin female connection would sure make life easier for big blockers and a lot cheaper to boot!

I am conveniently ignoring any of the voltage considerations on the premise our good friend mr resistor could help us it out if required.

PS No doubt this idea has been thought off before but I thought I'd ask the gurus anyway...


The best way is to dump the nand completly overnight a few times, Then flash Xell onto it and boot into linux and dump or flash your nand. It will dump 512 in about 2 minutes.

#3 torne

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Posted 15 December 2009 - 12:58 PM

It's slow because the LPT port is being used to drive the SPI serial bus directly, by toggling the lines on and off in the proper sequence. This is slow, because there is a limit on how fast you can toggle the state of the port, and to send or receive one byte of data over SPI this way you need to toggle the lines a dozen or more times to control the SPI data and clock lines. Having a USB LPT port is not going to make this faster, even if nandpro supported it; if anything it will make it slower. The actual LPT device on the end of the USB connection still has a limit on its switching speed.

SPI itself can be clocked very fast, and the USB SPI interface has proper hardware to directly speak the SPI protocol, so the PC can just send and receive bytes and the hardware takes care of the actual switching of the SPI lines at a high rate.




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