SUMMARY: Q: SS5 and broken graphics adapters?

From: Henrik Martin (euamhk@eua.ericsson.se)
Date: Thu Oct 06 1994 - 10:02:32 CDT


I received one answer on my question about the "broken" graphics
adapter cards in the SS5. It seems to be a sync problem as
Mike Fischbein says. BTW, I use the "standard" 19" color monitor that
comes with the SS5 (I believe it's a Sony inside?).

Rgds,

Henrik Martin
Ellemtel Telecommunication Systems Laboratories Sweden
Office phone: + 46 8 727 36 04 Fax: + 46 8 647 82 76
Email: Henrik.Martin@eua.ericsson.se

Here's the reply from Mike:

In article <36tb87$cf0@euas20.eua.ericsson.se> you wrote:
: Hi! Has anyone had problems with the SBus graphics adapters (MX)
: shipped with the SS5/85MHz boxes? We've had about 10 boxes from
: different batches which had their adapter cards broken. When the power
: was switched on, the screen looked like if the monitor sync was lost.
: You could see that some characters were output, but they were
: impossible to read.

Your graphics adapter wasn't broken; it had lost sync with
your monitor.

The newer frame buffers from sun (MX certainly qualifies) are
able to put out a variety of screen sizes and refresh rates.
That is, a given "graphics card" can, depending on several
items, generate different screen resolutions and refresh rates.

Note that there are also monitors (you never say which
monitor you use) that can switch between radically different
screen resolutions and refresh rates.

As long as the card and the monitor pick the *same* combination
(or reasonably close to it), you get a good picture. If they
don't, you don't. This is done on the card's power-up, and
rebooting Unix probably won't change it.

Some of the small (that is, non-coax) pins in the 13W3 cable
that Sun uses provide monitor capability sensing to the frame
buffer; of course, the monitor has to have the appropriate
combination of signals. All Sun monitors, and other monitors
*designed to work with Suns* have the appropriate signals;
other monitors may not. If the frame buffer does not detect
a signal, the usual default resolution is 1152x900 at 66 Hz.
If your monitor can't handle that (such as many SVGA monitors),
you can drop sync. If it can, then your frame buffer may be
getting a different signal, and trying to put out, say,
1280x1024 at 76 Hz, or even 1600x1280. If the monitor is
designed to work with Suns, ensure that it is turned on
at the same time or slightly before the CPU, and of course
that it is properly connected. If it isn't, and puts out
signals that the Sun finds misleading but can handle
1152x900 at 66 Hz, you can disconnect the video cable when
power cycling.

You can also write a program that diddles the appropriate registers
on the frame buffer to set the refresh/resolution within whatever
limits you desire (whether the attached monitor supports it or
not). If you know how to do that, fine; if not, you may wish
to contact your local Sun office or User's Group to see if they
have one available or know of a device-driver programmer who
can create one for you

        mike

-- 
Henrik Martín                     | 
Networked UNIX systems support    | "emacs is a fine operating system, 
Email: euamhk                     |  but I still prefer UNIX"
Tel  : 3604                       |



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:09:11 CDT