Are you using the IIsi with the upgraded MoBo RAM for this test? If so, try it on an unmodified IIsi. The extra RAM in Bank A may be messing with the Vampire Video DRAM buffering setup.
Too many variables and not enough specific information:
< or not enough coffee |) >
Which NuBus Video Card, 16bit or 24bit capable?
Is 640 x 480 @ 16bit for MoBo video on the IIsi in the Monitors Control Panel is available and works without the NuBus VidCard on board?
First (sleepy) guess is that having the NuBus Card installed gives the Monitors Control Panel the chance to poll the extra 7MB of RAM on the MoBo as a great big byte that the Vampire Video subsystem is incapable of chewing. Hence, the choking on the part of the MoBo's Video Buffering attempts at ingesting and excreting pixels at various settings.
If it's not working at 640x480, try 16bit at 12" RGB resolution, maybe MoBo Vampire Video won't choke trying to chew less pixels?
Dunno, strange stuff, it probably requires taking the trouble to do methodical troubleshooting to figure it out.
p.s. as regards the
Too many variables and not enough specific information:
< or not enough coffee |) >
Which NuBus Video Card, 16bit or 24bit capable?
Is 640 x 480 @ 16bit for MoBo video on the IIsi in the Monitors Control Panel is available and works without the NuBus VidCard on board?
First (sleepy) guess is that having the NuBus Card installed gives the Monitors Control Panel the chance to poll the extra 7MB of RAM on the MoBo as a great big byte that the Vampire Video subsystem is incapable of chewing. Hence, the choking on the part of the MoBo's Video Buffering attempts at ingesting and excreting pixels at various settings.
If it's not working at 640x480, try 16bit at 12" RGB resolution, maybe MoBo Vampire Video won't choke trying to chew less pixels?
Dunno, strange stuff, it probably requires taking the trouble to do methodical troubleshooting to figure it out.
p.s. as regards the