🚀 go-pugleaf

In <592ta3$2ni@usenet.rpi.edu> johnse2@rpi.edu (Eric Nels Johnson) writes:

>What different "CG" designators go with each Framebuffer type?  As best I
>can tell, CG6 == GX, but what is a CG12, CG3, etc?  Do both TurboGX and GX
>show up as CG6 at boot time?

These are also part of the 'cg6' grouping. The original 'cg6' is a P4-bus
vector-accelerated colour framebuffer, and the original Sbus GX was just a
copy of this with Sbus logic substituted for the P4-bus logic. That's why
the original Sbus GX's cover the space of two Sbus slots.

The cg12 is a 24-bit colour framebuffer. Like all of Sun's 24-bit products
(there were P4-bus cards, and the cg9 VME bus card, as well as the Sbus
cg12), they are supported in the version(s) of X/openwindows supplied with
the various releases of SunOS/Solaris. If you grab the X source distribution
from ftp.x.org, it doesn't support any of Sun's 24-bit frame buffers - only
the raw cg3/4's, and the cg6 line, are supported with code that works.

>Also, what are the relative performances?  I.E. will a CG3 be unbearably slow
>when compared to a CG6.  I have a chance to put a CG3 in my SS2, but I don't
>know if it will be fast enough to be worth it.

A cg3 is essentially the same as the P4-bus cg4, ie. a non-accelerated 8-bit
frame buffer, except it is more compact. It's as fast as the machine it's
installed in. I have a Sparc LC here with an on-board cg3, and it's much
faster in video performance than a cg3 fitted into an SS1.

The cg6 line are vector-accelerated. The P4-bus and original Sbus GX's used
the same 'lego' chipset (two very large ceramic packages), but I think Sun
either licensed the core architecture of these chips, or Legotec (?) just
produced newer, more integrated designs. I don't know very much about the
TurboGx, etc.

Regards,

Craig.

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            Craig Dewick. Send email to 'cdewick@lios.apana.org.au'
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