On Feb 4, 1:49 pm, Valter Prahlad <valter.prah...@fastwebnet.it> wrote: > Il giorno 4-02-2012 10:54, pdimage ha scritto: > > > Both the X800 and the X850 will convert to mac but I gather they are > > very troublesome and the dvi port never works as far as I know. > > As far as I can remember, the problem with a flashed PC X800 DVI port is it > won't drive a DVI monitor, but it will still work with a VGA one (provided > you use a DVI to VGA adapter on the port, of course). > In other words, after flashing the card, the two display ports still work, > but only for VGA monitors. > > I'm not 100% sure, but that's what I understood after getting an used PC > X800 for 25£. > (I didn't flash it yet, though, because it's working in my gaming PC right > now :-)
I went and read the 29 page thread about X800/X850 conversion on Strange Dogs. Themacelite forum may be gone, but Strange Dogs is still around. Yay! According to the long thread, things are as the previous poster wrote. As with many of these conversions, there's a reduced Firmware to fit in the PC 64K Flash. The full Mac Firmware requires a 128K flash chip, which usually means replacing the 64K Flash chip on the PC versions of the card. The X800 and X850 can be converted, but while the PC models have one DVI port and one VGA port, the DVI port will only work with a DVI to VGA adapter. The reason is that the GPU has the circuitry for the DVI (or ADC) output built in. On an Apple card with ADC/DVI outputs, the card uses the built-in circuitry to drive the ADC port and there is a separate Silicon Images DVI chip on the card to drive the DVI port. So, Apple card: ADC port driven by GPU. DVI port driven by dedicated chip. PC card: DVI port driven by GPU. VGA port doesn't need extra circuitry. And when you replace the PC X800/X850 BIOS with Mac Firmware, it tries to program the GPU to output ADC format to the DVI port -- which doesn't work. And there's no dedicated chip to drive DVI on the other port, and there's just a VGA connector there anyway. Now, ADC is electrically compatible with DVI. The converters between the two just rearrange the wires. They don't massage the signals -- except that DVI to ADC requires the addition of the 28V supply. So this suggests that the DVI port on a converted X800/X850 probably has the proper signals, but on the wrong pins. The HP Fire GL X3 has two DVI ports and has the dedicated DVI chip on board. Apparently, conversion of the Fire GL X3 does yield two working DVI ports. It may require the full Mac firmware (Flash chip replacement) to get that functionality. I can't remember any more. The Fire card is rated for a slower clock speed than the X850XT PE but gets good benchmarks, nevertheless. -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
