Hello,
We have developed a monitor (LCD display) for use displaying certain
windows of our software remotely. We are using proprietary means to
transmit our video signal to the monitor itself. These means of
transmission do not allow the identification from the monitor to make
it back to the PC.
We have a small box (referred to heretoforth as the box) that is
hooked up via a standard SVGA cable (HD-15 with all pins) to the PC.
We believe that we would like to implement DDC in this box and
transmit an EDID 1.3 structure back to the PC to identify the monitor
as being ours and to give Windows default configuration values for it
- we would like the monitor to be plug and play and also identified,
in Windows, as being one we made.
Computers are required to be running Windows XP Pro and to have second
monitor capability built in.
We have a Microsoft-supplied vendor id.
We are generally familiar with the DDC and EDID as well as other VESA
standards. We have read the VESA EDID Implementation Guide and the
VBE/DDC Standard documents (that does not mean that we understand what
is written in them or how to implement them). We used Phoenix to
generate EDID 1.3 data for the box.
In the box we have put an EEPROM (a Motorola 24LC02B) that we think
should implement DDC. It is connected with data set to pin 12 of the
SVGA connector, clock set to pin 15, power (+5v) set to pin 9 and with
ground from pin 10. We have pull-up resistors set on data and clock.
We loaded our EDID structure directly on the chip and in order.
When we use the Windows "Display Properties"/"Settings" control panel
we can see (using an oscilloscope) that the box is being queried by
Windows and we can see that the clock is functioning and data is being
transferred but Windows only recognizes the box as a default monitor
(and allows many settings outside of the range that we chose in our
EDID structure).
We have the Microsoft DDK and have perused it and the Microsoft Driver
Development site and not found any useful resources for building INF
files that might be used to identify/use our monitors.
Questions:
The one big, general question is what do we need to do in hardware and
software to have a device that we can plug in to a Windows machine
that will be recognized as being our own device and with certain
characteristics?
More specifically, what are we missing in our implementation of the
DDC/EDID? The VBE/DDC Standard document speaks of reporting
capabilities - do we need to implement this as well and what specific
hardware do we need to use to implement this if so? Is it sufficient
to implement one or both of those (DDC and VBE) correctly, or do we
also need an INF file and/or a display driver in Windows? Are there
any easy-to-use programs that can quickly generate this/these for us?
We have already spent a frustratingly large amount of time researching
this so we already have the general documentation on much of this.
We're not looking for general documentation - we'd like specifics.
Step-by-step instructions (or a flow chart - but specific and
step-by-step). Wiring diagrams. Simple byte orders. The VESA
documentation is -too- specific, here, in a sense. We have an EDID
data structure that was generated for us and don't feel that we need
to understand it intimately (perhaps we're wrong!).
Your assistance is appreciated. |
