Hi.  I'm a student here at Penn State, and am working on a group project
to build a low-speed computer-based oscilloscope.  To achieve this, we
are using a PIC 16C745 to sample an analog signal, and transmit the data
over the USB bus.  We verified that the microcontroller (uC) worked
properly by making it toggle the output of a port -- so we know the uC
is working properly.

Next, we uploaded the sample code provided with the USB firmware
(assembly version) into the chip, and wired it up exactly as described
in the last page of the firmware's documentation.  When we plugged the
USB cable into the computer, the circuit powered up just fine using the
USB's 5volt source.  I also checked V-USB, and it is a good 3.3 volts.
We tried running the chip with a 24 MHz crystal, and with the same 6 MHz
resonator as drawn up in the firmware documentation.  From the hardware
side, everything looks like it should...

On the computer, however, win98 recognizes that a new USB device is
attached, called %USB\UNKNOWN.DeviceDesc%.  It also says "no driver
files loaded".  The device manager initially has the device disabled. If
we enable it, the device then appears as being "malfunctioning" with a
yellow exclamation point next to it.  We tried 2 win98 second-edition
machines, and a win2k laptop -- they all respond the same way.

Because everything appears to be functioning properly in the hardware,
we are thinking this may be a driver problem.  Is there a driver for
windows we need to install to make the sample code work?  Is there some
debugging utilities you guys have that can help us determine the
problem?  Do you have any suggestions re: what may be wrong?

Thank you very much for your time,
Justin Mierta

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