Well, I got three replies to my questions - and thank you, you know who
you are. :-)  A few points were brought up that could use replies,
though:

>> The -3/150, as far as I can tell, does not drive anything out the
>> video connector at all - the display is solid black and stays that
>> way, even if I flip the switch to DIAG mode and press e for echo
>> mode when the self-test finishes.  (That machine has no other
>> framebuffer.)

One person said
> Check EEPROM settings.  Console can be on either serial port, bw2 or
> cg2.  You will get a blank screen unless the setting is correct.
Another said
> My first comment would be that Suns normally boot to their serial
> ports when they're in diag mode.  You should try connecting a
> terminal (or a null-modem to whatever you can scrounge if you don't
> have a terminal) to it.

Yes, I had a terminal on ttya when I did the DIAG mode stuff; that
terminal is how I "press[ed] e for echo mode".  And the message on the
terminal said that output would go to video too - but the video was
still displaying solid black.  And I tried mmap()ing /dev/bwtwo after
booting and scribbling all over it, and _still_ got solid black.

Everyone said the monitor cannot be readjusted for 1600x1280; the
reason I brought this up is that it certainly appeared to be capable of
approximately the right scan frequences - the characters were about the
correct size both vertically and horizontally; they were just broken up
horizontally, as if horizontal sync were badly mis-adjusted.  What _is_
the difference between the 1152x900 and the 1600x1280 monitors?
(Besides price. :-)

One person said

> I believe that the cgtwo and bwtwo drivers both check the eeprom
> settings for video size.  It has nothing (or not much) to do with the
> actual size of the card.

If this is true (I haven't checked the sources myself), it's a
moderately serious bug, because there's only one eeprom location for
screen size, and it can't always describe both screens at once. :-(

On the other hand, SunOS 3.5 on the (other) -3/260 says
	bwtwo0 at obmem ff000000 pri 4
	bwtwo0: resolution 1152 x 900
so in this respect we're no worse off. :-/  (SunOS 3.5 doesn't give
resolution figures for the cgtwo.)

					der Mouse

			    mouse@collatz.mcrcim.mcgill.edu