Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!apple!ames!sgi!bennett@galois.esd.sgi.com
From: bennett@galois.esd.sgi.com (Jim Bennett)
Newsgroups: comp.sys.sgi
Subject: Re: Questions about Personal IRIS
Summary: Some answers
Message-ID: <45921@sgi.sgi.com>
Date: 7 Dec 89 17:54:43 GMT
References: <12939@polya.Stanford.EDU>
Sender: bennett@galois.esd.sgi.com
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 54

In article <12939@polya.Stanford.EDU>, loan@polya.Stanford.EDU (James P. Loan) writes:
> 
> (1) I assume that the Personal IRIS comes standard with a 19"
>     monitor

Yes.

>     (it doesn't say so on our quote), so we'll have
>     the old 19" (1024x768) monitor from the 2400T as well as
>     the new one (1280x1024). What we'd like to do is be able
>     to run graphics programs on one (or the other) cpu and display
>     them on either of the monitors. The scenario is that
>     someone sits down at one of the monitors and is able to
>     runs graphics programs located on either machine.
>     Is this possible? If so, does something need to be done
>     to the system before it is shipped to us?

Its not possible:  The 2400 doesn't support the 1280x1024 resolution.
The PI will eventually support both resolutions, but currently doesn't,
and the 1024x768 monitor we will support is a 14" Sony with different
timing than the old 19" monitor on the 2400.

> (2) We are getting the so-called Super Graphics Upgrade to
>     give a total of 56 bitplanes. Are the 24 z-buffer planes
>     ONLY for z-buffering, or can we use 48 for color w/o
>     z-buffering so that we can use RGB mode in double-buffer
>     mode?

Double buffered RGB mode is supported.  For this we divide the color
bitplanes into two 12-bit buffers, and use hardware dithering to
approximate true colors.  This works surprisingly well.

The Z-buffer can be used in a variety of ways, but only the color
bitplanes and the overlay/underlay and popup planes can be displayed.

> (3) Does the SGI WorkSpace software and Diagnostics software
>     come standard?

Yes.

> (4) Is the data cache write-through and/or virtual-addressable?

The data cache works on physical addresses and is write-through with
write buffers.

> Thanks in advance,
> Peter Loan
> 
> loan%roses.stanford.edu@sunrise.stanford.edu
> loan@polya.stanford.edu

Jim Bennett

bennett@esd.sgi.com