> Many details need to be investigated and decided, but they're not on the > critical path to OGC1. That's important.
If we are depending on a DDC injection box, we should build and test a prototype to make sure it works. This can be mostly done by different people, freeing up the people designing the OGC board itself. > One question is whether there's a PCB-mount mating connector for the DVI > connector on the video board, with low reflections. I poked around a bit with google, and found DVI connectors with solder connections. They appear to be intended for cables. Connector is listed as 1.95 and the hood is 1.50. I assume that is the price in US$. If so. DVI connectors aren't as expensive as I thought they might be. http://www.action-electronics.com/computerconnectors.htm You could take a cable with the correct connectors for your monitor (BNC / 13W3 / HD-15) and solder the coax to this DVI connector. Solder a ribbon cable to the DDS pins on the DVI connector and run them to the DDC box. (or use twisted pair if it needs that.) If we put a connector on the ribbon cable at the box, we could use the same DDC box with DVI, HD-15 or 13W3. Just change the coax to one with the right connectors. > On the cable side, probably the latter. Assembling that connector to the > coax lines without fouling up the impedance m >atch has to involve some esoteric black magic. Any connector will introduce an impedance mismatch. At least that's what the prof said in transmission line class, back in the dark ages. The question is how can it be minimized. > > The first question is what do monitors have? Some small chip that just > > does the DDC? Problem is it might be one-time programmable, and/or > > require a specialized burner machine. > > Probably doesn't help us. We don't want a specialized programmed chip, we > want direct user access to the data bits. I agree that we will probably end up not using the chip they use in monitors. But a data sheet for the chip would be useful to have, so we know what to emulate. > It could be done either way, but I just find it easier to work on DIPs For the most part I agree. De-soldering a DIP from a board without destroying it is the exception. The legs love to stick to the walls of the hole, even with the use of solder-suckers and solder-wick. And even high-quality boards with experienced rework people are only good for about 5 replacements. With a low quality board you're lucky to replace a chip once without destroying the lands. So I never solder DIPs to a board, I always use sockets. _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
