> |        and     c) Are Apollo monitors likely to be usable with a sun?
> 
> No.  The scan rates are completely different and they aer fixed-frequency.
> I've tried.

Depends on the type. The monochrome, 19" monitors work with some fumbling quite
well with the old ECL monitor signals. I've just an old DN4500 mono at home,
and I was able to use an old SparcStation1 bw2 ECL framebuffer with a gender
changer. As they early monitor versions Sun shipped were quite similar to the
Sun 3/60 monitors we had, I'd guess that the CPU board graphics of the 3/260
will be the same.
You need to change the horz. frequency somewhat, and depending on the monitor
the pot will not reach far enough for this. I had to put a 200pF film capacitor
in parallel to the capacitor just below that pot to have the screen centered
correctly.

For color monitors, I also don't believe the 'original' old Apollo color ones
(1024x768 for DN3500 etc, 50.5 kHz * 50Hz) will work, their scan rates are
definitely different.
Color monitors of HP400 and Sun can be made to work, but they use different
sync mechanisms: HP uses sync-on-green, whereas Sun uses seperate sync. But the
scan rates seem to be the same (at least for the older CG3 and such).

Michael