Subject: sega circuit

From: [email-masked] (andrew longhorn )
Date: Thu, 13 Aug 92 08:26:47 EST

HELP,
I have been talking to dave stampe and trying to get my interface working
with my toshiba glasses and rend386.

Firstly, anyone please tell me if they are using the circuit supplied with
rend386 (the quad XOR providing the ~400hz oscillator).

Has anyone used the circuit from the karazm ftp site (which uses a 555 timer)?

The problem is, my glasses work PERFECTLY with the segavga program (which
is supplied with 2 dual-image rendered scenes and creates a static 3d image),
from karazm.

But only 
he left eye works perfectly in rend386, the right eye regularly but
sparcely (i.e. once every 1/2 or 1/4 second) gets a flash of the left image
bleeding through.

I have tried flipping the image and slowing down the render code in version 3
and flipping it in version 4 demo but nothing works.

My impressions are that my hardware is faulty, and jim brain mentioned my
oscillator may not be clean, but why does it work perfectly every time
(without fail) using the segavga program then?

The only difference I can see in the software is that the segavga program
uses:

0 - clear
1 - left clear
2 - right clear
3 - black

and rend 386 uses:

0 - clear
1 - right clear
2 - black
3 - left clear

but this is used by another different program again and also by everyone else
using rend386. Changing these to match the segavga program didn't fix it
either?????!!???!??

So, I really am stumped, If worse comes to worse, I would like someone who
has a circuit that works to email me a diagram so I can build one from scratch
again. Otherwise, I think I'll join a monastry and gain enlightenment without
the use of VR (It takes a bit longer but maybe I could even learn to levitate)

Exasperated,
Andrew Longhorn.

And, NO, I don't feel like including my 3d .sig, It probably wouldn't work
either!

---

From: [email-masked] (Joseph D. Gradecki)
Date: Wed, 12 Aug 92 22:08:52 -0600

Hello,

  I am using the XOR cicuit and it works just fine with Rend386.  I created
a PCB circuit for the circuit as well.  All of which is documented in the
third issue of PCVR.

joe

---

From: [email-masked] (andrew longhorn )
Date: Thu, 13 Aug 92 21:17:58 EST

There are actually 3 circuits (that I have found) that use the quad
2 input XOR gates. I implemented the one the steals the 10 v from the
DTR to power the circuit. using only that 4030 IC. I went all over it
with a CRO today against rend386 and segavga. As near as I could figure
they worked the same, except rend386 supplied an AC to DTR at 10(+/-)10 volts
(which was equalised to ~11v by the diode) and segavga supplied a constant
+11v.
   Other than that the signals were very close from either program and I
could only attribute the bad performance to inexact driving oscillator
(the wave being output varied slightly because of the rounded AC power
I think).

I am now just about done building a new circuit that drives the oscillator
from a 555 timer and trimmed to ~400Hz by a trimpot. This circuit has the
disadvantage of needing an external 9v to 10v supply, but I think it will
be better being adjustable and clean.

I'll let you know how I go. If the new circuit works, I'll hook them both
up and test the differences.

The new circuit I am building comes from 2 supplied in a file called
"circuit.lcd" at plaza.aarnet.edu.au and was drawn by Glen Harris
[email-masked] (James Cook Uni. of North Queensland).

I have to go to Melbourne tomorrow but I'll be get it going saturday and
let you all know.

Andrew (patience is a virtuality) Longhorn.

---

From: Dave Stampe-Psy+Eng <dstamp@watserv1>
Date: Thu, 13 Aug 92 08:57:03 -0400

Actually, the power source SHOULD be constant!  Maybe there's something else
going on here (serial port screwy, or something...)

- Dave Stampe

---

From: [email-masked] (andrew longhorn )
Date: Thu, 20 Aug 92 08:16:26 EST

I have also had these messages coming my way,

-- From [email-masked] Wed Aug 19 11:31:04 1992
-- From: [email-masked]
-- Date: 18 Aug 92 18:06
-- To: [email-masked]
-- Subject: Glasses!
-- Content-Length: 765
-- 
--           Hello,
--           I have been following your trials with interest, until I
--           jumped into the same boat.  Now I'm sinking too!  A friend
--           just built the 4030 schematic.
-- 
--           I am noticing exactly the same thing, I think.  The left eye
--           is fairly clean, but the right eye allows the left image to
--           jump in every second or so.  Even when the -r option is used
--           to switch the left and right eyes from the software point of
--           view, the right eye is still screwed up.  It seems to say
--           that there is something wrong with the interface design or
--           the way REND386 is interfacing ( what else! ;-) ).  Have you
--           had any luck in isolating the problem??
--           Thanks much, James
-- 

and he wrote again:

-- From [email-masked] Wed Aug 19 11:31:09 1992
-- From: [email-masked]
-- Date: 18 Aug 92 18:22
-- To: [email-masked]
-- Subject: More testing
-- Content-Length: 370
-- 
--           I have also just tried demo4 and got exactly the same
--           results that you reported.
-- 
--           The left eye is very clean, no flickering.  But the right
--           eye is really bad.  Both the left and the right image seem
--           to be coming through.
-- 
--           Hmmmm....the plot thickens.
--           Cheers, James
--           [email-masked]
-- 

And I received another one from someone else this morning:

-- From [email-masked] Wed Aug 19 17:41:10 1992
-- From: [email-masked] (Eyal Lebedinsky)
-- Subject: Re: shutter problems - info
-- To: [email-masked] (andrew longhorn)
-- Date: Wed, 19 Aug 92 17:38:39 EST
-- X-Mailer: ELM [version 2.3 PL11]
-- Content-Length: 541
-- 
-- Hi,
-- 
-- I use the 4030-only circuit and have the same problems as you do. I have
-- the Sega glasses. My machine is 386/40. I checked the cuircuit on a 'scope
-- and it seems to be up to spec (I slowed the osc. down to 400Hz from the
-- 2KHz to reduce leakage. The .01u cap is now .05u in my curcuit).
-- 
-- Segavga works great. My own software works fine. demo4 fails with right eye
-- problems. Without glasses the left image looks darker (I use cube.plg) than
-- the right, is this the case with you too?
-- 
-- -- 
-- Regards
-- 	Eyal Lebedinsky		[email-masked]
-- 

It seems as though something is DEFINITELY a little screwy here.

Andrew Longhorn.

---

From: [email-masked]
Date: Thu, 27 Aug 92 08:09:09 MDT

>I have also had these messages coming my way,

stuff deleted
Andrew:

With respect to the "right eye bleeding problem."  After a much closer look
at my own setup (the 4030 circuit on a PS/2 70/16 running REND386) I do see
bleeding (and glitches in the right eye).  In particular, if you close your
left eye, I can see the" L" in the left screen AND the" R" in the right
screen.  If you close your right eye, the left image is clear and you do
not see anything but the" L".  Also see the same thing on a 486/33.  It
seemed to be more pronounced on the 486 machine but that may be due to my
increased awareness of the bleeding.

We are building a new 4030 circuit with a trim pot to see if the problem
persists.  Should get this done and tested today (8/27/92).  Will keep you
posted.
--
tkl
--
---------------------------------------------------
T. K. Larson, Idaho National Engineering Laboratory
P.O. Box 1625, M/S 2090
Idaho Falls, Idaho 83415-2090
Phone (208) 525-5334; Fax (208) 525-5996
INTERNET: [email-masked]
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