New USB host controller drivers: usbhcd183.zip
March 16, 2012 by email@example.com
I have updated the USB host controller drivers
USBUHCD.SYS, USBOHCD.SYS, USBEHCD.SYS, USBD.SYS
I have now placed these on hobbes.
They will eventually make it into directory:
a.) USBEHCD.SYS: changes in resetting the HC on system boot / HC reset
b.) IMPORTANT: changes to USBD.SYS. version 10.162 has a fundamental design
flaw that prevents it from handling devices that return configuration data >
1024 bytes. In practice, many USB 2.0 web cams have > 1024 bytes of
As a first step, I had to change the USBD interface towards client drivers
(something like usbprt.sys, usbmouse.sys, usbser.sys etc.) .
There might be client drivers around that act as filter drivers and these
can be affected.
It is possible that these will subsequently trap this updated USBD.SYS. If
this happens, I would be interested to know.
I still haven't updated USBD.SYS to support > 1024 bytes of config data
(this will be the next step) but I have added some code to prevent
the traps that used to happen with USBD.SYS 10.162 when you'd attach such
web cam device with > 1024 bytes of config data.
In any case, USBD.SYS is still experimental.
Important note: make sure that USBEHCD.SYS goes after
USBUHCD.SYS/USBOHCD.SYS in config.sys !
I have not yet succeeded in coming up with a solution that would render
config.sys sequence irrelevant.