[rescue] SS20 screen not found

[David McMackins II]

Great, thanks for the info! You're right that the 8MB modules are quite
expensive, and I can't even find a 4MB module for sale anywhere. I'm
thinking a better move for now would be to replace it with an SBus
framebuffer card, then I could even reclaim that socket for more memory
capacity.

Is there any good technical documentation on these VSIMM modules?
Unless there are proprietary components that can't be replicated, I
feel like it shouldn't be that complicated to design a replacement from
new parts. 8MB of fast memory should be easy to come by. The main thing
I'd need is some specification of how the module is supposed to
identify itself and provide the included logo image and such, as well
as the pinout. Exact board dimensions would also be nice but I can get
out the calipers if I have to.
-- 
Regards,

David E. McMackins II
www.mcmackins.org

On Wed, 2025-10-29 at 00:56 -0400, Mouse via rescue wrote:
> > I'm back again with yet more SPARCstation issues!  [...]
> 
> > I fired up my SS20 today [...]
> 
> > Looking in the serial output, I see "screen not found".  My first
> > suspicion is that the extra-long module with the video RAM has gone
> > bad, but I'd like some confirmation that that would cause this
> > symptom.
> 
> Indeed it could.  If that is missing (or, equivalently, so bad it
> appears missing, or bad enough for the ROM code to decide it's not
> usable), the machine will treat itself as having no framebuffer, and
> "screen not found" is exactly what I'd expect in that case.
> 
> > If that's the case, where's a good place to find replacements for
> > those, and what is the proper name I should search for?
> 
> Plausible search terms include cg14, cgfourteen, and VSIMM.  If you
> want one of the 8M ones (capable of more than a megapixel at >8bpp),
> prepare yourself for a certain amount of sticker shock.  4M VSIMMs
> are
> *relatively* cheap and available; the 8M ones somewhat less so.
> 
> > Will this happen only when the framebuffer itself is inoperable, or
> > would that also happen if it were functioning properly but there
> > were
> > no monitor connected?
> 
> No, no-monitor-connected is not normally an error condition and does
> not, in my experience, lead to the ROM code saying "screen not
> found".
> 
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