*** Adendum **

This patch creates a modified  USBUHCD.SYS for UHCI style USB host controllers. It should support mainboards equipped with an INTEL, VIA or ETEQ(?) chipset, as well as VIA USB addon cards.

To Install it get the newest USB Printer drivers from "The OS/2 Device Driver Repository" and install it according to the instructions.  copy the file included  "via.pat" to the \os2\boot directory then boot the computer the the os/2 command prompt.  change to the \os2\boot directory and type 

patch via.pat /A

This will patch the USBUHCD.SYS to work with the VIA Chipset.  When you reboot you should be able to see the USB Printer.  remember you also need the corect printer driver for your particular printer.


USB chipsets from OPTI, SIS, NEC, CMD, ALI/ACER or AMD are not supported,
as their OHCI architecture is totally different.


Summary of modifications
------------------------

* added workaround for VIA chipset bug
* added support and autodetection for upto 4 mainboard ports. (not tested)
* fixed load message to screen (also fixed by IBM in the 4/29/99 build)
* various stability enhancements


FAQ
---

1. Q: Will there be support for OHCI style USB chipsets soon?
   A: Most likely not. Use a cheap "VIA 83C572" USB addon card instead.

2. Q: Which USB peripherals are supported in OS/2?
   A: There are existings generic drivers for USB hubs, mice, keyboards, 
      modems, speakers and removeable disks.  Still, it might be possible
      that certain models of such devices are not or only partially supported. 
      It is up to the device manufacturers to make their products conforming
      to some USB device class specification, or to require individual drivers.

3. Q: An USB peripheral is recognized sometimes and sometimes not.
   A: From my experience, the device enumeration process is still not working
      perfectly, if multiple devices have to be initialized at the same time.
      Try to unplug and replug the peripheral. Or try to swap the connectors.
      Or try to use an additional hub.

4. Q: I want to use both USB ports on the mainboard, and an USB addon card.
   A: Duplicate the line "BASEDEV=USBUHCD.SYS" in config.sys.

5. Q: How can I display a load message from USBUHCD.SYS?
   A: Use the /V option. "DEVICE=This is a modified version of IBM's OS/2 driver (Jan-06-99) for UHCI style 
USB host controllers. It should support mainboards equipped with an INTEL, 
VIA or ETEQ(?) chipset, as well as VIA USB addon cards.

USB chipsets from OPTI, SIS, NEC, CMD, ALI/ACER or AMD are not supported,
as their OHCI architecture is totally different.


Summary of modifications
------------------------

* added workaround for VIA chipset bug
* added support and autodetection for upto 4 mainboard ports. (not tested)
* fixed load message to screen (also fixed by IBM in the 4/29/99 build)
* various stability enhancements


FAQ
---

1. Q: Will there be support for OHCI style USB chipsets soon?
   A: Most likely not. Use a cheap "VIA 83C572" USB addon card instead.

2. Q: Which USB peripherals are supported in OS/2?
   A: There are existings generic drivers for USB hubs, mice, keyboards, 
      modems, speakers and removeable disks.  Still, it might be possible
      that certain models of such devices are not or only partially supported. 
      It is up to the device manufacturers to make their products conforming
      to some USB device class specification, or to require individual drivers.

*** I have gotten an epson stylus color 900 printer to work in USB mode using
      the newest USB printer drivers from "The OS/2 Device Driver Repository" 

3. Q: An USB peripheral is recognized sometimes and sometimes not.
   A: From my experience, the device enumeration process is still not working
      perfectly, if multiple devices have to be initialized at the same time.
      Try to unplug and replug the peripheral. Or try to swap the connectors.
      Or try to use an additional hub.

4. Q: I want to use both USB ports on the mainboard, and an USB addon card.
   A: Duplicate the line "BASEDEV=USBUHCD.SYS" in config.sys.

5. Q: How can I display a load message from USBUHCD.SYS?
   A: Use the /V option. "DEVICE=USBUHCD.SYS /V"

6. Q: What about USB hot-plugging capabilities?
   A: USB devices can be plugged and unplugged at any time. They are not
      required to be present at boot-up. Still, it is required that all
      OS/2 device drivers (that might be required at runtime) are already
      loaded at boot-up. Also when plugging more than one device of the same
      device class, the assignment of physical devices to OS/2 device names
      might be not well predictable.

7. Q: After plugging and unplugging USB peripherals, the WPS hardware manager 
      tree is displaying "ghost" USB devices.
   A: This is a WPS bug. Use the text mode utility called RMVIEW.EXE instead.




******************************************************************
*** WARNING: This software is provived without any warranties. ***
***          It has not been proven to be free of defects.     ***
***          Any use is at the user's own risk!                ***
******************************************************************
  
"CMD", "VIA", "INTEL", "ETEQ", "OPTI", "SIS", "NEC", "ALI", "ACER", 
"AMD", "IBM", "USB", "OS/2", "WPS", "OHCI", "UHCI"
are trade marks of their respective owners.

October 1999     Robert Lalla, Loerrach, Germany         rlalla@stepnet.de 

August 2000      Bob Baleno, Ayer, MA. USA             bbaleno@ultranet.com
(all I did was take the patch that Robert Lalla so kindly gave me and added to this doc on how to use it)

Many thanks.
