Franc Zabkar wrote in message
...
On Thu, 20 May 2010 14:17:20 +0100, "N_Cook" put
finger to keyboard and composed:

I got back to this today. Saved to disc the existing (corrupted ?) data
in
the serial EEPROM and cut the SDA line to the Ez-usb chip.
The EZbus mixer is no longer "Becoming Ezbus" and a blank screen.
But windows recognises a USB device connected and by UVCView/USB view the
USB is working up to the USB chip , reading

---===Device Information===---

ConnectionStatus:
Current Config Value: 0x00 - Device Bus Speed: Full
Device Address: 0x00
Open Pipes: 0
*!*ERROR: No open pipes!

===Device Descriptor===
bLength: 0x12
bDescriptorType: 0x01
bcdUSB: 0x0100
bDeviceClass: 0xFF - This is a Vendor Specific
Device
bDeviceSubClass: 0xFF
bDeviceProtocol: 0xFF
bMaxPacketSize0: 0x40 = (64) Bytes
idVendor: 0x0547idProduct:
0x2131
bcdDevice: 0x0004
iManufacturer: 0x00
iProduct: 0x00
iSerialNumber: 0x00
bNumConfigurations: 0x01

ie Cypress VID/PID

Where to now? presumably forcing a pipe somehow

You already know more about USB than I do. :-)

However, I wonder if the data in the serial EEPROM are checksummed, in
which case it may be possible to confirm its integrity.

ISTM that you've at least confirmed that the EZ-USB chip has sanity,
if you weren't already convinced by your scope tests.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.


Switching SDA line after 3 seconds still keeps the USB open but wrong
identity for the mixer firmware installer. Not had a chance to connect it up
to a pc but I'm assuming it will not software connect if expecting the mixer
VID/VID/endpoint. When next I have some time I will load the installer.exe
into hex_reader_XVI32 and see if I can swap VID / PID hex-codes to fool it
into thinking it is an EZbus rather than EZusb it is hooked to. Probably
checksummed there but simple enough to try.