Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!batcomputer!cornell!uw-beaver!mit-eddie!media-lab!wave
From: wave@media-lab.MEDIA.MIT.EDU (Michael B. Johnson)
Newsgroups: comp.sys.next
Subject: Towards a cheap Head Mounted display
Message-ID: <5599@media-lab.MEDIA.MIT.EDU>
Date: 3 Apr 91 20:45:17 GMT
Reply-To: wave@media-lab.media.mit.edu (Michael B. Johnson)
Distribution: comp
Organization: MIT Media Lab, Cambridge MA
Lines: 38

I was having a discussion with a friend of mine who builds head mounted
displays (Private Eye).  He was showing me the chip he (and another guy)
had designed and built to allow the Private Eye to look like a CGA display
so that people could just plug it into their PC.  Pointing to the size of
the ASIC chip, he pointed out that there was a reasonable amount of silicon
devoted to transposing the data from CGA format to the Private Eye's 
on-the-side-format (similar to transposing data on the CM-2).  We talked 
about what it would take to put the Private Eye into another machine, namely
a NeXT machine.  

Since you can also address the Private as a 720 X 2?? display, it seemed 
feasible that if you could convince the Window Server to render to a bitmap
of that resolution, you'd then have to transpose the data and get it to 
the Private Eye.

We came on the idea that it might be possible to use the DSP to transpose
the data and you could then shove it out the DSP port.

So I guess I have two questions:  Does anybody have any ideas where to look
about getting the Window Server to render to a bitmap of a particular 
resolution?  I assume this is very similar to the problem of writing a driver
for a printer.

The other question involves DSP use:  have people done anything like this, 
i.e. using the DSP to transpose a stream of data moving through it?  I assume
this isn't that strange a notion of using a DSP chip...


Any pointers would be appreciated; e-mail is probably a better idea than
posting - there's too much traffic here already.  If there is sufficient
interest in the answers, I'll post a summary of the useful data I get.


-- 

-->  Michael B. Johnson
-->  MIT Media Lab      --  Computer Graphics & Animation Group
-->  (617) 253-0663     --  wave@media-lab.media.mit.edu