[rescue] Recommended 13w3 to VGA adapter

[Chase Rayfield]

On Sun, Jul 31, 2022 at 11:08:19PM -0400, Mouse wrote:
> But a new monitor on an old system - such as a flatscreen on a
> SPARCstation from the 32-bit pizza-box era - is a disaster.  Each end
> thinks it is the end who is supposed to specify what the video signal
> looks like.  I've been frustrated trying to get the cg14s in my SS20s
> to drive 1920x1080 monitors.  I've succeeded for two monitors

That said, one thing I haven't tried yet (since I was under the impression
that 13W3 to VGA adapters almost never work on non-multisync monitors... I
guess I'm wrong there) is trying to do 4BNC -> 13W3 -> VGA, specifically
for my sun3. Does anyone know if that'll work or if that actually will
require me to find a multisync monitor? 

So the deal is that Sun framebuffers are designed to operate at fixed frequencies... and so are Sun monitors. There are only a handful of frequencies and resolutions that are officially supported. You can hack the sun framebuffers via the prom to do other frequencies and resolutions however often enough but its always fixed preprogrammed frequencies. That is how people are able to run 1080p or 1920x1200 etc... which were never official resolutions.

Modern LCDs just tell the video card what they can do via EDID and the video card outputs one of those that is also within its specs. When connecting to a Sun it none of the sun framebuffers can do that part so they just blindly output whatever they are programmed to do and hope for the best.

So in practice yes you need a multisync monitor CRT or LCD (even though in theory you could get the timings just right to work with a non sun non multisync). A multisync monitor will sync up with whatever signals it is given as long as it is within it's sync range (I have seen sun framebuffers go outside of this and the monitor say "out of sync" etc... but I could hook it up to a monitor with a wider sync range change the res to one that the other monitor could sync and and swap it back and it worked fine). If it isn't multisync its just going to be much harder to get working unless it is a sun monitor that supports the official fixed frequencies. 


Chase



  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sunhelp.org/pipermail/rescue_sunhelp.org/attachments/20220801/695e60b9/attachment.html>