JPAC + Matrox G450 + Linux won't sync

[andreasb]

Hi,

I have a Matrox G450 -> JPAC -> 25" polo. The computer is running linux 2.4.* with maxtrox FB driver. The JPAC has only one jumper on 15khz. When I use advcfg to setup my display, I select standard resolution and 15khz generic. This gives me the following modelines,

mode "256x240-60"
   # D: 5.544 MHz, H: 15.750 kHz, V: 60.115 Hz
   geometry 256 240 256 480 8
   timings 180375 32 32 16 3 32 3
   rgba 8/0,8/0,8/0,0/0
endmode

The problem is that JPAC still dont show "ON SYNC", only "SYNC IN". My LCD monitor goes out-of-sync, when connected, so I presume that the refresh rate changed in some way.

I allso tried to make a dos bootcd with advcfg on it, and got the same problem there, so I don't think its releated to the linux drivers.

Any ideas?

[whammoed]

I tried using a Matrox G400 with framebuffer and svga lib and I had trouble getting either to output resolutions like that with a low pclock (below 7).  Some people have said that they don't have a problem but I could never get it to work.  I am currently using a radeon 7000 with no problems.  Perhaps you are having a similar issue with your G450?

[andreasb]

I have tried

mode "640x240-60"
    # D: 12.084 MHz, H: 15.734 kHz, V: 60.053 Hz
    geometry 640 240 640 480 16
    timings 82756 64 16 14 5 48 3
    rgba 5/11,6/5,5/0,0/0
endmode

too without any luck...

Going to trying my other computer with radeon 9200SE, and see if it helps.

-Andreas