SUMMARY: Vertical refresh rate on GX-based 4/75 color monitors?

From: Art Hays - PSTAFF (lsr-vax!
Date: Thu May 16 1991 - 15:07:02 CDT

        My original query:

> I am considering integrating non-Sun supplied color monitors on some black
> and white machines I am upgrading to GX-based color SS2's (these monitors are much
> cheaper than Sun's). I have figured out what cables to order, but
> I cant discern from the manuals I have whether the GX drives the color
> monitor at 66Hz or 76Hz. Some literature suggests one, some the other. The
> SS2's I have looked at dont seem to be running at 76Hz by judging flicker
> with the eye. I need this info to determine if the monitors will work, and would
> appreciate if someone could let me know. Respond to me, and I will summarize.

        From the replies I received (thanks to those who responded) some things
are clear, and some are not. What is clear is that Sun has been transistioning
from 66Hz GX boards to 76Hz GX boards recently (note that a 16" SS2 system we
took delivery on app. 2 months ago was still 66Hz). What is not clear is how
the various components may be mixed. I have conflicting info in this area.
This summarizes the possibilities:

        1.) Some monitors shipped with 66Hz GX systems may be capable of 66Hz only.
        2.) Monitors shipped with 76Hz GX systems may be capable of doing both
            frequencies, or 76Hz only.
        3.) New 76Hz GX boards may operate only at 76Hz, or might be able to sense
            what type of monitor is connected and drive it at 76Hz or 66Hz. It is
            not clear how the sensing is done, perhaps thru the extra pins on the
            13W3 connector.

        The non-Sun monitor I was looking at is the Sony GDM-1936. It is
a 20" multiscanning monitor that, according to the specs (not actual experience :-)), would handle the freq. of the GX at 66Hz. The GX at 76Hz, however, requires a
horiz freq of 71.7KHz. The GDM-1936 goes up to 71KHz. My rep said that Sony would
not guarantee it would work at 71.7KHz. I can get it for app. $1400 less than
Sun's monitor (qty 15 price).

        I had a query about the cables I would use. Sun sells adapter cables
to go from their 13W3 connector to BNCs. What is needed (note I havent ordered
these and cant verify that it is accurate):

        #530-1440 13W3 male to male 4' cable
        #530-1446 13W3 to BNC adapter

        Using the above adapters might present a problem is the 76Hz GX wants
to sense the monitor type thru the extra pins on the 13W3 cable.

        Please post any followup messages to me and I will summarize again if
it seems warranted.

Art Hays, Nat. Eye Institute, uunet!lsr-vax!art
Nat. Institutes of Health, Bethesda, MD (301) 496-7143


This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:06:14 CDT