Control packets (see pg 199 in usb1.1 spec)

00 01 02 03 04 05 06 07

00    - Request Type
01    - Request
02,03 - Value
04,05 - Index/Offset
06,07 - Data length


Request Type
80 - device to host; type standard; recipient device
c0 - device to host; type vendor  ; recipient device   
40 - host to device; type vendor  ; recipient device

c0, 40 are used for sony communication


Request 
06 - GET_DESCRIPTOR
80 - Sony proprietary. goes with 40 on first bit
81 - Sony proprietary. goes with c0 on first bit


Data length
Only the 6th byte seems to be used. The value of the 6th byte converted to decimal is the number of bytes to be read/written.